Oracle Linux 8 Security Technical Implementation Guide

  • Version/Release: V1R9
  • Published: 2023-12-01
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This Security Technical Implementation Guide is published as a tool to improve the security of Department of Defense (DOD) information systems. The requirements are derived from the National Institute of Standards and Technology (NIST) 800-53 and related documents. Comments or proposed revisions to this document should be sent via email to the following address: disa.stig_spt@mail.mil.
b
The OL 8 audit package must be installed.
AU-3 - Medium - CCI-000130 - V-248519 - SV-248519r853745_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030180
Vuln IDs
  • V-248519
Rule IDs
  • SV-248519r853745_rule
Without establishing what type of events occurred and their source, location, and outcome, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. Audit record content that may be necessary to satisfy this requirement includes, for example, time stamps, source and destination addresses, user/process identifiers, event descriptions, success/fail indications, filenames involved, and access control or flow control rules invoked. Associating event types with detected events in OL 8 audit logs provides a means of investigating an attack, recognizing resource utilization or capacity thresholds, or identifying an improperly configured OL 8 system. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000038-GPOS-00016, SRG-OS-000039-GPOS-00017, SRG-OS-000040-GPOS-00018, SRG-OS-000041-GPOS-00019, SRG-OS-000042-GPOS-00021, SRG-OS-000051-GPOS-00024, SRG-OS-000054-GPOS-00025, SRG-OS-000062-GPOS-00031, SRG-OS-000122-GPOS-00063, SRG-OS-000254-GPOS-00095, SRG-OS-000255-GPOS-00096, SRG-OS-000337-GPOS-00129, SRG-OS-000348-GPOS-00136, SRG-OS-000349-GPOS-00137, SRG-OS-000350-GPOS-00138, SRG-OS-000351-GPOS-00139, SRG-OS-000352-GPOS-00140, SRG-OS-000353-GPOS-00141, SRG-OS-000354-GPOS-00142, SRG-OS-000358-GPOS-00145, SRG-OS-000365-GPOS-00152, SRG-OS-000392-GPOS-00172, SRG-OS-000475-GPOS-00220
Checks: C-51953r779121_chk

Verify the audit service is configured to produce audit records. Check that the audit service is installed with the following command: $ sudo yum list installed audit If the "auditd" package is not installed, this is a finding.

Fix: F-51907r779122_fix

Configure the audit service to produce audit records containing the information needed to establish when (date and time) an event occurred. Install the audit service (if the audit service is not already installed) with the following command: $ sudo yum install audit

b
OL 8 audit records must contain information to establish what type of events occurred, the source of events, where events occurred, and the outcome of events.
AU-3 - Medium - CCI-000130 - V-248520 - SV-248520r853746_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030181
Vuln IDs
  • V-248520
Rule IDs
  • SV-248520r853746_rule
Without establishing what type of events occurred and their source, location, and outcome, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. Audit record content that may be necessary to satisfy this requirement includes, for example, time stamps, source and destination addresses, user/process identifiers, event descriptions, success/fail indications, filenames involved, and access control or flow control rules invoked. Associating event types with detected events in OL 8 audit logs provides a means of investigating an attack, recognizing resource utilization or capacity thresholds, or identifying an improperly configured OL 8 system. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000038-GPOS-00016, SRG-OS-000039-GPOS-00017, SRG-OS-000040-GPOS-00018, SRG-OS-000041-GPOS-00019, SRG-OS-000042-GPOS-00021, SRG-OS-000051-GPOS-00024, SRG-OS-000054-GPOS-00025, SRG-OS-000062-GPOS-00031, SRG-OS-000122-GPOS-00063, SRG-OS-000254-GPOS-00095, SRG-OS-000255-GPOS-00096, SRG-OS-000337-GPOS-00129, SRG-OS-000348-GPOS-00136, SRG-OS-000349-GPOS-00137, SRG-OS-000350-GPOS-00138, SRG-OS-000351-GPOS-00139, SRG-OS-000352-GPOS-00140, SRG-OS-000353-GPOS-00141, SRG-OS-000354-GPOS-00142, SRG-OS-000358-GPOS-00145, SRG-OS-000365-GPOS-00152, SRG-OS-000392-GPOS-00172, SRG-OS-000475-GPOS-00220
Checks: C-51954r818593_chk

Verify the audit service is configured to produce audit records with the following command: $ sudo systemctl status auditd.service auditd.service - Security Auditing Service Loaded:loaded (/usr/lib/systemd/system/auditd.service; enabled; vendor preset: enabled) Active: active (running) since Tues 2020-12-11 12:56:56 EST; 4 weeks 0 days ago If the audit service is not "active" and "running", this is a finding.

Fix: F-51908r779125_fix

Configure the audit service to produce audit records containing the information needed to establish when (date and time) an event occurred with the following commands: $ sudo systemctl enable auditd.service $ sudo systemctl start auditd.service

c
OL 8 must be a vendor-supported release.
CM-6 - High - CCI-000366 - V-248521 - SV-248521r779129_rule
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
OL08-00-010000
Vuln IDs
  • V-248521
Rule IDs
  • SV-248521r779129_rule
Configuring the operating system to implement organization-wide security implementation guides and security checklists verifies compliance with federal standards and establishes a common security baseline across the DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example, registry settings; account, file, and directory permission settings; and settings for functions, ports, protocols, services, and remote connections.
Checks: C-51955r779127_chk

Verify the version of the operating system is vendor supported. Check the version of the operating system with the following command: $ udo cat /etc/oracle-release Oracle Linux Server release 8.2 Current End of Premier Support for Oracle Linux 8 is July 2029, while Extended Support might consider an extended term. If the release is not supported by the vendor, this is a finding.

Fix: F-51909r779128_fix

Upgrade to a supported version of the operating system.

b
The OL 8 operating system must implement the Endpoint Security for Linux Threat Prevention tool.
SI-2 - Medium - CCI-001233 - V-248522 - SV-248522r943103_rule
RMF Control
SI-2
Severity
Medium
CCI
CCI-001233
Version
OL08-00-010001
Vuln IDs
  • V-248522
Rule IDs
  • SV-248522r943103_rule
Adding endpoint security tools can provide the capability to automatically take actions in response to malicious behavior, which can provide additional agility in reacting to network threats. These tools also often include a reporting capability to provide network awareness of the system, which may not otherwise exist in an organization's systems management regime.
Checks: C-51956r943102_chk

Check that the following package has been installed: # rpm -qa | grep -i mcafeetp If the "mcafeetp" package is not installed, this is a finding. Verify that the daemon is running: # ps -ef | grep -i mfetpd If the daemon is not running, this is a finding.

Fix: F-51910r779131_fix

Install and enable the latest McAfee ENSLTP package.

b
OL 8 vendor-packaged system security patches and updates must be installed and up to date.
CM-6 - Medium - CCI-000366 - V-248523 - SV-248523r779135_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010010
Vuln IDs
  • V-248523
Rule IDs
  • SV-248523r779135_rule
Timely patching is critical for maintaining the operational availability, confidentiality, and integrity of information technology (IT) systems. However, failure to keep operating system and application software patched is a common mistake made by IT professionals. New patches are released daily, and it is often difficult for even experienced System Administrators to keep abreast of all the new patches. When new weaknesses in an operating system exist, patches are usually made available by the vendor to resolve the problems. If the most recent security patches and updates are not installed, unauthorized users may take advantage of weaknesses in the unpatched software. The lack of prompt attention to patching could result in a system compromise.
Checks: C-51957r779133_chk

Verify the operating system security patches and updates are installed and up to date. Updates are required to be applied with a frequency determined by the site or Program Management Office (PMO). Obtain the list of available package security updates from Oracle. The URL for updates is https://linux.oracle.com/errata/. It is important to note that updates provided by Oracle may not be present on the system if the underlying packages are not installed. Check that the available package security updates have been installed on the system with the following command: $ sudo yum history list | more Loaded plugins: langpacks, product-id, subscription-manager ID | Command line | Date and time | Action(s) | Altered ------------------------------------------------------------------------------- 70 | install aide | 2020-03-05 10:58 | Install | 1 69 | update -y | 2020-03-04 14:34 | Update | 18 EE 68 | install vlc | 2020-02-21 17:12 | Install | 21 67 | update -y | 2020-02-21 17:04 | Update | 7 EE If package updates have not been performed on the system within the timeframe that the site/program documentation requires, this is a finding. Typical update frequency may be overridden by Information Assurance Vulnerability Alert (IAVA) notifications from CYBERCOM. If the operating system is not in compliance with the Information Assurance Vulnerability Management (IAVM) process, this is a finding.

Fix: F-51911r779134_fix

Install the operating system patches or updated packages available from Oracle within 30 days or sooner as local policy dictates.

c
OL 8 must implement NIST FIPS-validated cryptography for the following: To provision digital signatures, to generate cryptographic hashes, and to protect data requiring data-at-rest protections in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards.
AC-17 - High - CCI-000068 - V-248524 - SV-248524r928551_rule
RMF Control
AC-17
Severity
High
CCI
CCI-000068
Version
OL08-00-010020
Vuln IDs
  • V-248524
Rule IDs
  • SV-248524r928551_rule
Use of weak or untested encryption algorithms undermines the purposes of using encryption to protect data. The operating system must implement cryptographic modules adhering to the higher standards approved by the federal government since this provides assurance they have been tested and validated. OL 8 uses GRUB 2 as the default bootloader. Note that GRUB 2 command-line parameters are defined in the "kernelopts" variable of the "/boot/grub2/grubenv" file for all kernel boot entries. The command "fips-mode-setup" modifies the "kernelopts" variable, which in turn updates all kernel boot entries. The fips=1 kernel option needs to be added to the kernel command line during system installation so that key generation is done with FIPS-approved algorithms and continuous monitoring tests in place. Users must also ensure the system has plenty of entropy during the installation process by moving the mouse around, or if no mouse is available, ensuring that many keystrokes are typed. The recommended amount of keystrokes is 256 and more. Less than 256 keystrokes may generate a nonunique key. Satisfies: SRG-OS-000033-GPOS-00014, SRG-OS-000125-GPOS-00065, SRG-OS-000250-GPOS-00093, SRG-OS-000393-GPOS-00173, SRG-OS-000394-GPOS-00174, SRG-OS-000423-GPOS-00187
Checks: C-51958r928549_chk

Verify the operating system implements DOD-approved encryption to protect the confidentiality of remote access sessions. Check to see if FIPS mode is enabled with the following command: $ fips-mode-setup --check FIPS mode is enabled If FIPS mode is "enabled", check to see if the kernel boot parameter is configured for FIPS mode with the following command: $ sudo grub2-editenv list | grep fips kernelopts=root=/dev/mapper/ol-root ro resume=/dev/mapper/ol-swap rd.lvm.lv=ol/root rd.lvm.lv=ol/swap rhgb quiet fips=1 boot=UUID=25856928-386b-4205-9a0e-a2953ae2712d audit=1 audit_backlog_limit=8192 pti=on random.trust_cpu=on slub_debug=P page_poison=1 If the kernel boot parameter is configured to use FIPS mode, check to see if the system is in FIPS mode with the following command: $ sudo cat /proc/sys/crypto/fips_enabled 1 If FIPS mode is not "enabled", the kernel boot parameter is not configured for FIPS mode, or the system does not have a value of "1" for "fips_enabled" in "/proc/sys/crypto", this is a finding.

Fix: F-51912r928550_fix

Configure the operating system to implement DOD-approved encryption by following the steps below: To enable strict FIPS compliance, the fips=1 kernel option must be added to the kernel boot parameters during system installation so key generation is done with FIPS-approved algorithms and continuous monitoring tests in place. Enable FIPS mode after installation (not strict FIPS-compliant) with the following command: $ sudo fips-mode-setup --enable Reboot the system for the changes to take effect.

b
All OL 8 local disk partitions must implement cryptographic mechanisms to prevent unauthorized disclosure or modification of all information that requires at-rest protection.
SC-28 - Medium - CCI-001199 - V-248525 - SV-248525r917893_rule
RMF Control
SC-28
Severity
Medium
CCI
CCI-001199
Version
OL08-00-010030
Vuln IDs
  • V-248525
Rule IDs
  • SV-248525r917893_rule
OL 8 systems handling data requiring "data-at-rest" protections must employ cryptographic mechanisms to prevent unauthorized disclosure and modification of the information at rest. Selection of a cryptographic mechanism is based on the need to protect the integrity of organizational information. The strength of the mechanism is commensurate with the security category and/or classification of the information. Organizations have the flexibility to either encrypt all information on storage devices (i.e., full disk encryption) or encrypt specific data structures (e.g., files, records, or fields). Satisfies: SRG-OS-000185-GPOS-00079, SRG-OS-000404-GPOS-00183, SRG-OS-000405-GPOS-00184
Checks: C-51959r917892_chk

Verify OL 8 prevents unauthorized disclosure or modification of all information requiring at-rest protection by using disk encryption. If there is a documented and approved reason for not having data-at-rest encryption at the operating system level, such as encryption provided by a hypervisor or a disk storage array in a virtualized environment, this requirement is not applicable. Verify all system partitions are encrypted with the following command: $ sudo blkid /dev/mapper/ol-root: UUID="67b7d7fe-de60-6fd0-befb-e6748cf97743" TYPE="crypto_LUKS" Every persistent disk partition present must be of type "crypto_LUKS". If any partitions other than the boot partition or pseudo file systems (such as "/proc" or "/sys") are not listed, ask the administrator to indicate how the partitions are encrypted. If there is no evidence that these partitions are encrypted, this is a finding.

Fix: F-51913r779140_fix

Configure OL 8 to prevent unauthorized modification of all information at rest by using disk encryption. Encrypting a partition in an already-installed system is more difficult because existing partitions will need to be resized and changed. To encrypt an entire partition, dedicate a partition for encryption in the partition layout.

b
OL 8 must display the Standard Mandatory DoD Notice and Consent Banner before granting local or remote access to the system via an SSH logon.
AC-8 - Medium - CCI-000048 - V-248526 - SV-248526r858561_rule
RMF Control
AC-8
Severity
Medium
CCI
CCI-000048
Version
OL08-00-010040
Vuln IDs
  • V-248526
Rule IDs
  • SV-248526r858561_rule
Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. System use notifications are required only for access via logon interfaces with human users and are not required when such human interfaces do not exist. The banner must be formatted in accordance with applicable DoD policy. Use the following verbiage for operating systems that can accommodate banners of 1300 characters: "You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details." Use the following verbiage for operating systems that have severe limitations on the number of characters that can be displayed in the banner: "I've read & consent to terms in IS user agreem't." Satisfies: SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088
Checks: C-51960r858560_chk

Verify any publicly accessible connection to the operating system displays the Standard Mandatory DoD Notice and Consent Banner before granting access to the system. Check for the location of the banner file being used with the following command: $ sudo grep -ir banner /etc/ssh/sshd_config* banner /etc/issue This command will return the banner keyword and the name of the file that contains the SSH banner (in this case "/etc/issue"). If the line is commented out, this is a finding. If conflicting results are returned, this is a finding. View the file specified by the banner keyword to check that it matches the text of the Standard Mandatory DoD Notice and Consent Banner: "You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details." If the system does not display a graphical logon banner or the banner does not match the Standard Mandatory DoD Notice and Consent Banner, this is a finding. If the text in the file does not match the Standard Mandatory DoD Notice and Consent Banner, this is a finding.

Fix: F-51914r779143_fix

Configure OL 8 to display the Standard Mandatory DoD Notice and Consent Banner before granting access to the system via the SSH. Edit the "/etc/ssh/sshd_config" file to uncomment the banner keyword and configure it to point to a file that will contain the logon banner (this file may be named differently or be in a different location if using a version of SSH that is provided by a third-party vendor). An example configuration line is: banner /etc/issue Either create the file containing the banner or replace the text in the file with the Standard Mandatory DoD Notice and Consent Banner. The DoD-required text is: "You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details." The SSH service must be restarted for changes to take effect.

b
OL 8 must display a banner before granting local or remote access to the system via a graphical user logon.
AC-8 - Medium - CCI-000048 - V-248527 - SV-248527r779147_rule
RMF Control
AC-8
Severity
Medium
CCI
CCI-000048
Version
OL08-00-010049
Vuln IDs
  • V-248527
Rule IDs
  • SV-248527r779147_rule
Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. System use notifications are required only for access via logon interfaces with human users and are not required when such human interfaces do not exist. Satisfies: SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088
Checks: C-51961r779145_chk

Note: This requirement assumes the use of the OL 8 default graphical user interface, Gnome Shell. If the system does not have any graphical user interface installed, this requirement is Not Applicable. Verify OL 8 displays a banner before granting access to the operating system via a graphical user logon. Determine if the operating system displays a banner at the logon screen with the following command: $ sudo grep banner-message-enable /etc/dconf/db/local.d/* banner-message-enable=true If "banner-message-enable" is set to "false" or is missing, this is a finding.

Fix: F-51915r779146_fix

Configure the operating system to display a banner before granting access to the system. Note: If the system does not have a graphical user interface installed, this requirement is Not Applicable. Create a database to contain the system-wide graphical user logon settings (if it does not already exist) with the following command: $ sudo touch /etc/dconf/db/local.d/01-banner-message Add the following lines to the [org/gnome/login-screen] section of the "/etc/dconf/db/local.d/01-banner-message": [org/gnome/login-screen] banner-message-enable=true Run the following command to update the database: $ sudo dconf update

b
OL 8 must display the Standard Mandatory DoD Notice and Consent Banner before granting local or remote access to the system via a graphical user logon.
AC-8 - Medium - CCI-000048 - V-248528 - SV-248528r779150_rule
RMF Control
AC-8
Severity
Medium
CCI
CCI-000048
Version
OL08-00-010050
Vuln IDs
  • V-248528
Rule IDs
  • SV-248528r779150_rule
Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. System use notifications are required only for access via logon interfaces with human users and are not required when such human interfaces do not exist. The banner must be formatted in accordance with applicable DoD policy. Use the following verbiage for operating systems that can accommodate banners of 1300 characters: "You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details." Satisfies: SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088
Checks: C-51962r779148_chk

Note: This requirement assumes the use of the OL 8 default graphical user interface, Gnome Shell. If the system does not have any graphical user interface installed, this requirement is Not Applicable. Verify OL 8 displays the Standard Mandatory DoD Notice and Consent Banner before granting access to the operating system via a graphical user logon. Check that the operating system displays the exact Standard Mandatory DoD Notice and Consent Banner text with the command: $ sudo grep banner-message-text /etc/dconf/db/local.d/* banner-message-text= 'You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only.\nBy using this IS (which includes any device attached to this IS), you consent to the following conditions:\n-The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations.\n-At any time, the USG may inspect and seize data stored on this IS.\n-Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose.\n-This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy.\n-Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details. ' Note: The "\n" characters are for formatting only. They will not be displayed on the graphical interface. If the banner does not match the Standard Mandatory DoD Notice and Consent Banner exactly, this is a finding.

Fix: F-51916r779149_fix

Configure OL 8 to display the Standard Mandatory DoD Notice and Consent Banner before granting access to the system. Note: If the system does not have a graphical user interface installed, this requirement is Not Applicable. Add the following lines to the [org/gnome/login-screen] section of the "/etc/dconf/db/local.d/01-banner-message": banner-message-text='You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only.\nBy using this IS (which includes any device attached to this IS), you consent to the following conditions:\n-The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations.\n-At any time, the USG may inspect and seize data stored on this IS.\n-Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose.\n-This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy.\n-Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details. ' Note: The "\n" characters are for formatting only. They will not be displayed on the graphical interface. Run the following command to update the database: $ sudo dconf update

b
OL 8 must display the Standard Mandatory DoD Notice and Consent Banner before granting local or remote access to the system via a command line user logon.
AC-8 - Medium - CCI-000048 - V-248529 - SV-248529r779153_rule
RMF Control
AC-8
Severity
Medium
CCI
CCI-000048
Version
OL08-00-010060
Vuln IDs
  • V-248529
Rule IDs
  • SV-248529r779153_rule
Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. System use notifications are required only for access via logon interfaces with human users and are not required when such human interfaces do not exist. The banner must be formatted in accordance with applicable DoD policy. Use the following verbiage for operating systems that can accommodate banners of 1300 characters: "You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details." Satisfies: SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088
Checks: C-51963r779151_chk

Verify OL 8 displays the Standard Mandatory DoD Notice and Consent Banner before granting access to the operating system via a command line user logon. Check that OL 8 displays a banner at the command line login screen with the following command: $ sudo cat /etc/issue If the banner is set correctly, it will return the following text: "You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details." If the banner text does not match the Standard Mandatory DoD Notice and Consent Banner exactly, this is a finding.

Fix: F-51917r779152_fix

Configure OL 8 to display the Standard Mandatory DoD Notice and Consent Banner before granting access to the system via command line logon. Edit the "/etc/issue" file to replace the default text with the Standard Mandatory DoD Notice and Consent Banner. The DoD-required text is: "You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests -- not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details."

b
All OL 8 remote access methods must be monitored.
AC-17 - Medium - CCI-000067 - V-248530 - SV-248530r779156_rule
RMF Control
AC-17
Severity
Medium
CCI
CCI-000067
Version
OL08-00-010070
Vuln IDs
  • V-248530
Rule IDs
  • SV-248530r779156_rule
Remote access services, such as those providing remote access to network devices and information systems, which lack automated monitoring capabilities increase risk and make remote user access management difficult at best. Remote access is access to DoD nonpublic information systems by an authorized user (or an information system) communicating through an external, non-organization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Automated monitoring of remote access sessions allows organizations to detect cyberattacks and ensure ongoing compliance with remote access policies by auditing connection activities of remote access capabilities, such as Remote Desktop Protocol (RDP), on a variety of information system components (e.g., servers, workstations, notebook computers, smartphones, and tablets).
Checks: C-51964r779154_chk

Verify that OL 8 monitors all remote access methods. Check that remote access methods are being logged by running the following command: $ sudo grep -E '(auth.*|authpriv.*|daemon.*)' /etc/rsyslog.conf /etc/rsyslog.d/*.conf /etc/rsyslog.conf:auth.*;authpriv.*;daemon.* /var/log/secure If "auth.*", "authpriv.*", or "daemon.*" are not configured to be logged, this is a finding.

Fix: F-51918r779155_fix

Configure OL 8 to monitor all remote access methods by installing rsyslog with the following command: $ sudo yum install rsyslog Add or update the following lines to the "/etc/rsyslog.conf" file: auth.*;authpriv.*;daemon.* /var/log/secure The "rsyslog" service must be restarted for the changes to take effect. To restart the "rsyslog" service, run the following command: $ sudo systemctl restart rsyslog.service

b
OL 8, for PKI-based authentication, must validate certificates by constructing a certification path (which includes status information) to an accepted trust anchor.
IA-5 - Medium - CCI-000185 - V-248531 - SV-248531r860907_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000185
Version
OL08-00-010090
Vuln IDs
  • V-248531
Rule IDs
  • SV-248531r860907_rule
Without path validation, the relying party cannot make an informed trust decision when presented with any certificate not already explicitly trusted. A trust anchor is an authoritative entity represented via a public key and associated data. It is used in the context of public key infrastructures, X.509 digital certificates, and DNSSEC. When there is a chain of trust, usually the top entity to be trusted becomes the trust anchor; it can be, for example, a Certification Authority (CA). A certification path starts with the subject certificate and proceeds through a number of intermediate certificates up to a trusted root certificate, typically issued by a trusted CA. This requirement verifies that a certification path to an accepted trust anchor is used for certificate validation and that the path includes status information. Path validation is necessary for a relying party to make an informed trust decision when presented with any certificate not already explicitly trusted. Status information for certification paths includes certificate revocation lists or online certificate status protocol responses. Validation of the certificate status information is out of scope for this requirement. Satisfies: SRG-OS-000066-GPOS-00034, SRG-OS-000384-GPOS-00167
Checks: C-51965r858601_chk

Verify OL 8, for PKI-based authentication, has valid certificates by constructing a certification path (which includes status information) to an accepted trust anchor. Note: If the System Administrator demonstrates the use of an approved alternate multifactor authentication method, this requirement is not applicable. Check that the system has a valid DoD root CA installed with the following command: $ sudo openssl x509 -text -in /etc/sssd/pki/sssd_auth_ca_db.pem Certificate: Data: Version: 3 (0x2) Serial Number: 1 (0x1) Signature Algorithm: sha256WithRSAEncryption Issuer: C = US, O = U.S. Government, OU = DoD, OU = PKI, CN = DoD Root CA 3 Validity Not Before: Mar 20 18:46:41 2012 GMT Not After : Dec 30 18:46:41 2029 GMT Subject: C = US, O = U.S. Government, OU = DoD, OU = PKI, CN = DoD Root CA 3 Subject Public Key Info: Public Key Algorithm: rsaEncryption If the root ca file is not a DoD-issued certificate with a valid date installed in the "/etc/sssd/pki/sssd_auth_ca_db.pem" location, this is a finding.

Fix: F-51919r818597_fix

Configure OL 8, for PKI-based authentication, to validate certificates by constructing a certification path (which includes status information) to an accepted trust anchor. Obtain a valid copy of the DoD root CA file from the PKI CA certificate bundle at cyber.mil and copy it into the following file: /etc/sssd/pki/sssd_auth_ca_db.pem

b
OL 8, for certificate-based authentication, must enforce authorized access to the corresponding private key.
IA-5 - Medium - CCI-000186 - V-248532 - SV-248532r779162_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000186
Version
OL08-00-010100
Vuln IDs
  • V-248532
Rule IDs
  • SV-248532r779162_rule
If an unauthorized user obtains access to a private key without a passcode, that user would have unauthorized access to any system where the associated public key has been installed.
Checks: C-51966r779160_chk

Verify the SSH private key files have a passcode. For each private key stored on the system, use the following command: $ sudo ssh-keygen -y -f /path/to/file If the contents of the key are displayed, this is a finding.

Fix: F-51920r779161_fix

Create a new private and public key pair that uses a passcode with the following command: $ sudo ssh-keygen -n [passphrase]

b
OL 8 must encrypt all stored passwords with a FIPS 140-2 approved cryptographic hashing algorithm.
IA-5 - Medium - CCI-000196 - V-248533 - SV-248533r877397_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000196
Version
OL08-00-010110
Vuln IDs
  • V-248533
Rule IDs
  • SV-248533r877397_rule
Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Unapproved mechanisms that are used for authentication to the cryptographic module are not verified and therefore cannot be relied on to provide confidentiality or integrity, and DoD data may be compromised. FIPS 140-2 is the current standard for validating that mechanisms used to access cryptographic modules use authentication that meets DoD requirements.
Checks: C-51967r779163_chk

Verify that the shadow password suite configuration is set to encrypt passwords with a FIPS 140-2 approved cryptographic hashing algorithm. Check the hashing algorithm that is being used to hash passwords with the following command: $ sudo cat /etc/login.defs | grep -i crypt ENCRYPT_METHOD SHA512 If "ENCRYPT_METHOD" does not equal SHA512 or greater, this is a finding.

Fix: F-51921r779164_fix

Configure OL 8 to encrypt all stored passwords. Edit/modify the following line in the "/etc/login.defs" file and set "[ENCRYPT_METHOD]" to SHA512: ENCRYPT_METHOD SHA512

b
OL 8 must employ FIPS 140-2 approved cryptographic hashing algorithms for all stored passwords.
IA-5 - Medium - CCI-000196 - V-248534 - SV-248534r877397_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000196
Version
OL08-00-010120
Vuln IDs
  • V-248534
Rule IDs
  • SV-248534r877397_rule
The system must use a strong hashing algorithm to store the password. Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised.
Checks: C-51968r779166_chk

Confirm that the interactive user account passwords are using a strong password hash with the following command: $ sudo cut -d: -f2 /etc/shadow $6$kcOnRq/5$NUEYPuyL.wghQwWssXRcLRFiiru7f5JPV6GaJhNC2aK5F3PZpE/BCCtwrxRc/AInKMNX3CdMw11m9STiql12f/ Password hashes "!" or "*" indicate inactive accounts not available for logon and are not evaluated. If any interactive user password hash does not begin with "$6$", this is a finding.

Fix: F-51922r779167_fix

Lock all interactive user accounts not using SHA-512 hashing until the passwords can be regenerated with SHA-512.

b
The OL 8 shadow password suite must be configured to use a sufficient number of hashing rounds.
IA-5 - Medium - CCI-000196 - V-248535 - SV-248535r880546_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000196
Version
OL08-00-010130
Vuln IDs
  • V-248535
Rule IDs
  • SV-248535r880546_rule
The system must use a strong hashing algorithm to store the password. The system must use a sufficient number of hashing rounds to ensure the required level of entropy. Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised.
Checks: C-51969r880545_chk

Check that a minimum number of hash rounds is configured by running the following command: $ sudo grep -E "^SHA_CRYPT_" /etc/login.defs If only one of "SHA_CRYPT_MIN_ROUNDS" or "SHA_CRYPT_MAX_ROUNDS" is set, and this value is below "5000", this is a finding. If both "SHA_CRYPT_MIN_ROUNDS" and "SHA_CRYPT_MAX_ROUNDS" are set, and the value for either is below "5000", this is a finding.

Fix: F-51923r818600_fix

Configure OL 8 to encrypt all stored passwords with a strong cryptographic hash. Edit/modify the following line in the "/etc/login.defs" file and set "SHA_CRYPT_MIN_ROUNDS" to a value no lower than "5000": SHA_CRYPT_MIN_ROUNDS 5000

c
OL 8 operating systems booted with United Extensible Firmware Interface (UEFI) must require authentication upon booting into single-user mode and maintenance.
AC-3 - High - CCI-000213 - V-248537 - SV-248537r779177_rule
RMF Control
AC-3
Severity
High
CCI
CCI-000213
Version
OL08-00-010140
Vuln IDs
  • V-248537
Rule IDs
  • SV-248537r779177_rule
If the system does not require valid authentication before it boots into single-user or maintenance mode, anyone who invokes single-user or maintenance mode is granted privileged access to all files on the system. GRUB 2 is the default boot loader for OL 8 and is designed to require a password to boot into single-user mode or modify the boot menu.
Checks: C-51971r779175_chk

For systems that use BIOS, this is not applicable. Determine if an encrypted password is set for the grub superusers account. On systems that use UEFI, use the following command: $ sudo grep -iw grub2_password /boot/efi/EFI/redhat/user.cfg GRUB2_PASSWORD=grub.pbkdf2.sha512.[password_hash] If the grub superusers account password does not begin with "grub.pbkdf2.sha512", this is a finding.

Fix: F-51925r779176_fix

Configure the system to require an encrypted grub bootloader password for the grub superusers account with the grub2-setpassword command, which creates/overwrites the "/boot/efi/EFI/redhat/user.cfg" file. Generate an encrypted grub2 password for the grub superusers account with the following command: $ sudo grub2-setpassword Enter password: Confirm password:

b
OL 8 operating systems booted with United Extensible Firmware Interface (UEFI) must have a unique name for the grub superusers account when booting into single-user mode and maintenance.
AC-3 - Medium - CCI-000213 - V-248538 - SV-248538r818603_rule
RMF Control
AC-3
Severity
Medium
CCI
CCI-000213
Version
OL08-00-010141
Vuln IDs
  • V-248538
Rule IDs
  • SV-248538r818603_rule
If the system does not require valid authentication before it boots into single-user or maintenance mode, anyone who invokes single-user or maintenance mode is granted privileged access to all files on the system. GRUB 2 is the default boot loader for OL 8 and is designed to require a password to boot into single-user mode or modify the boot menu. The GRUB 2 superuser account is an account of last resort. Establishing a unique username for this account hardens the boot loader against brute force attacks. Due to the nature of the superuser account database being distinct from the OS account database, this allows the use of a username that is not among those within the OS account database. Examples of non-unique superusers names are (root, superuser, unlock, etc.)
Checks: C-51972r818602_chk

For systems that use BIOS, this is Not Applicable. Verify that a unique name is set as the "superusers" account: $ sudo grep -iw "superusers" /boot/efi/EFI/redhat/grub.cfg set superusers="[someuniqueUserNamehere]" export superusers If "superusers" is identical to any OS account name or is missing a name, this is a finding.

Fix: F-51926r779179_fix

Configure the system to replace "root" with a unique name for the grub superusers account. Edit the /etc/grub.d/01_users file and add or modify the following lines: set superusers="[someuniqueUserNamehere]" export superusers password_pbkdf2 [someuniqueUserNamehere] ${GRUB2_PASSWORD} Generate a new grub.cfg file with the following command: $ sudo grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg

b
OL 8 operating systems booted with a BIOS must have a unique name for the grub superusers account when booting into single-user and maintenance modes.
AC-3 - Medium - CCI-000213 - V-248539 - SV-248539r818605_rule
RMF Control
AC-3
Severity
Medium
CCI
CCI-000213
Version
OL08-00-010149
Vuln IDs
  • V-248539
Rule IDs
  • SV-248539r818605_rule
If the system does not require valid authentication before it boots into single-user or maintenance mode, anyone who invokes single-user or maintenance mode is granted privileged access to all files on the system. GRUB 2 is the default boot loader for OL 8 and is designed to require a password to boot into single-user mode or modify the boot menu. The GRUB 2 superuser account is an account of last resort. Establishing a unique username for this account hardens the boot loader against brute force attacks. Due to the nature of the superuser account database being distinct from the OS account database, this allows the use of a username that is not among those within the OS account database. Examples of non-unique superusers names are (root, superuser, unlock, etc.)
Checks: C-51973r818604_chk

For systems that use UEFI, this is Not Applicable. Verify that a unique name is set as the "superusers" account: $ sudo grep -iw "superusers" /boot/grub2/grub.cfg set superusers="[someuniqueUserNamehere]" export superusers If "superusers" is identical to any OS account name or is missing a name, this is a finding.

Fix: F-51927r779182_fix

Configure the system to replace "root" with a unique name for the grub superusers account. Edit the /etc/grub.d/01_users file and add or modify the following lines: set superusers="[someuniqueUserNamehere]" export superusers password_pbkdf2 [someuniqueUserNamehere] ${GRUB2_PASSWORD} Generate a new grub.cfg file with the following command: $ sudo grub2-mkconfig -o /boot/grub2/grub.cfg

c
OL 8 operating systems booted with a BIOS must require authentication upon booting into single-user and maintenance modes.
AC-3 - High - CCI-000213 - V-248540 - SV-248540r779186_rule
RMF Control
AC-3
Severity
High
CCI
CCI-000213
Version
OL08-00-010150
Vuln IDs
  • V-248540
Rule IDs
  • SV-248540r779186_rule
If the system does not require valid authentication before it boots into single-user or maintenance mode, anyone who invokes single-user or maintenance mode is granted privileged access to all files on the system. GRUB 2 is the default boot loader for OL 8 and is designed to require a password to boot into single-user mode or modify the boot menu.
Checks: C-51974r779184_chk

For systems that use UEFI, this is not applicable. Determine if an encrypted password is set for the grub superusers account. On systems that use a BIOS, use the following command: $ sudo grep -iw grub2_password /boot/grub2/user.cfg GRUB2_PASSWORD=grub.pbkdf2.sha512.[password_hash] If the grub superusers account password does not begin with "grub.pbkdf2.sha512", this is a finding.

Fix: F-51928r779185_fix

Configure the system to require a grub bootloader password for the grub superusers account with the grub2-setpassword command, which creates/overwrites the "/boot/grub2/user.cfg" file. Generate an encrypted grub2 password for the grub superusers account with the following command: $ sudo grub2-setpassword Enter password: Confirm password:

b
OL 8 operating systems must require authentication upon booting into rescue mode.
AC-3 - Medium - CCI-000213 - V-248541 - SV-248541r779189_rule
RMF Control
AC-3
Severity
Medium
CCI
CCI-000213
Version
OL08-00-010151
Vuln IDs
  • V-248541
Rule IDs
  • SV-248541r779189_rule
If the system does not require valid root authentication before it boots into emergency or rescue mode, anyone who invokes emergency or rescue mode is granted privileged access to all files on the system.
Checks: C-51975r779187_chk

Determine if the system requires authentication for rescue mode with the following command: $ sudo grep sulogin-shell /usr/lib/systemd/system/rescue.service ExecStart=-/usr/lib/systemd/systemd-sulogin-shell rescue If the "ExecStart" line is configured for anything other than "/usr/lib/systemd/systemd-sulogin-shell rescue" or is commented out or missing, this is a finding.

Fix: F-51929r779188_fix

Configure the system to require authentication upon booting into rescue mode by adding the following line to the "/usr/lib/systemd/system/rescue.service" file: ExecStart=-/usr/lib/systemd/systemd-sulogin-shell rescue

b
OL 8 operating systems must require authentication upon booting into emergency mode.
AC-3 - Medium - CCI-000213 - V-248542 - SV-248542r779192_rule
RMF Control
AC-3
Severity
Medium
CCI
CCI-000213
Version
OL08-00-010152
Vuln IDs
  • V-248542
Rule IDs
  • SV-248542r779192_rule
If the system does not require valid root authentication before it boots into emergency or rescue mode, anyone who invokes emergency or rescue mode is granted privileged access to all files on the system.
Checks: C-51976r779190_chk

Determine if the system requires authentication for emergency mode with the following command: $ sudo grep sulogin-shell /usr/lib/systemd/system/emergency.service ExecStart=-/usr/lib/systemd/systemd-sulogin-shell emergency If the "ExecStart" line is configured for anything other than "/usr/lib/systemd/systemd-sulogin-shell emergency" or is commented out or missing, this is a finding.

Fix: F-51930r779191_fix

Configure the system to require authentication upon booting into emergency mode by adding the following line to the "/usr/lib/systemd/system/emergency.service" file: ExecStart=-/usr/lib/systemd/systemd-sulogin-shell emergency

b
The OL 8 "pam_unix.so" module must be configured in the system-auth file to use a FIPS 140-2 approved cryptographic hashing algorithm for system authentication.
IA-7 - Medium - CCI-000803 - V-248543 - SV-248543r818608_rule
RMF Control
IA-7
Severity
Medium
CCI
CCI-000803
Version
OL08-00-010159
Vuln IDs
  • V-248543
Rule IDs
  • SV-248543r818608_rule
Unapproved mechanisms that are used for authentication to the cryptographic module are not verified and therefore cannot be relied on to provide confidentiality or integrity, and DoD data may be compromised. OL 8 systems using encryption are required to use FIPS-compliant mechanisms for authenticating to cryptographic modules. FIPS 140-2 is the current standard for validating that mechanisms used to access cryptographic modules use authentication that meets DoD requirements. This allows for Security Levels 1, 2, 3, or 4 for use on a general-purpose computing system.
Checks: C-51977r818606_chk

Verify that the "pam_unix.so" module is configured to use sha512. Check that pam_unix.so module is configured to use sha512 in /etc/pam.d/system-auth with the following command: $ sudo grep password /etc/pam.d/system-auth | grep pam_unix password sufficient pam_unix.so sha512 If "sha512" is missing, or is commented out, this is a finding.

Fix: F-51931r818607_fix

Configure OL 8 to use a FIPS 140-2 approved cryptographic hashing algorithm for system authentication. Edit/modify the following line in the "/etc/pam.d/system-auth" file to include the sha512 option for pam_unix.so: password sufficient pam_unix.so sha512

b
The OL 8 "pam_unix.so" module must be configured in the password-auth file to use a FIPS 140-2 approved cryptographic hashing algorithm for system authentication.
IA-7 - Medium - CCI-000803 - V-248544 - SV-248544r818611_rule
RMF Control
IA-7
Severity
Medium
CCI
CCI-000803
Version
OL08-00-010160
Vuln IDs
  • V-248544
Rule IDs
  • SV-248544r818611_rule
Unapproved mechanisms that are used for authentication to the cryptographic module are not verified and therefore cannot be relied on to provide confidentiality or integrity, and DoD data may be compromised. OL 8 systems using encryption are required to use FIPS-compliant mechanisms for authenticating to cryptographic modules. FIPS 140-2 is the current standard for validating that mechanisms used to access cryptographic modules use authentication that meets DoD requirements. This allows for Security Levels 1, 2, 3, or 4 for use on a general-purpose computing system.
Checks: C-51978r818609_chk

Verify that the "pam_unix.so" module is configured to use sha512 in "/etc/pam.d/password-auth" with the following command: $ sudo grep password /etc/pam.d/password-auth | grep pam_unix password sufficient pam_unix.so sha512 If "sha512" is missing, or is commented out, this is a finding.

Fix: F-51932r818610_fix

Configure OL 8 to use a FIPS 140-2 approved cryptographic hashing algorithm for system authentication. Edit/modify the following line in the "/etc/pam.d/password-auth" file to include the sha512 option for pam_unix.so: password sufficient pam_unix.so sha512

b
OL 8 must prevent system daemons from using Kerberos for authentication.
IA-7 - Medium - CCI-000803 - V-248545 - SV-248545r779201_rule
RMF Control
IA-7
Severity
Medium
CCI
CCI-000803
Version
OL08-00-010161
Vuln IDs
  • V-248545
Rule IDs
  • SV-248545r779201_rule
Unapproved mechanisms that are used for authentication to the cryptographic module are not verified and therefore cannot be relied on to provide confidentiality or integrity, and DoD data may be compromised. OL 8 systems using encryption are required to use FIPS-compliant mechanisms for authenticating to cryptographic modules. The key derivation function (KDF) in Kerberos is not FIPS compatible. Ensuring the system does not have any keytab files present prevents system daemons from using Kerberos for authentication. A keytab is a file containing pairs of Kerberos principals and encrypted keys. FIPS 140-2 is the current standard for validating that mechanisms used to access cryptographic modules use authentication that meets DoD requirements. This allows for Security Levels 1, 2, 3, or 4 for use on a general-purpose computing system.
Checks: C-51979r779199_chk

Verify that OL 8 prevents system daemons from using Kerberos for authentication. If the system is a server using krb5-server-1.17-18.el8.x86_64 or newer, this requirement is not applicable. If the system is a workstation using krb5-workstation-1.17-18.el8.x86_64 or newer, this requirement is not applicable. Check if there are available keytabs with the following command: $ sudo ls -al /etc/*.keytab If this command produces any file(s), this is a finding.

Fix: F-51933r779200_fix

Configure OL 8 to prevent system daemons from using Kerberos for authentication. Remove any files with the .keytab extension from the operating system.

b
The krb5-workstation package must not be installed on OL 8.
IA-7 - Medium - CCI-000803 - V-248546 - SV-248546r779204_rule
RMF Control
IA-7
Severity
Medium
CCI
CCI-000803
Version
OL08-00-010162
Vuln IDs
  • V-248546
Rule IDs
  • SV-248546r779204_rule
Unapproved mechanisms that are used for authentication to the cryptographic module are not verified and therefore cannot be relied on to provide confidentiality or integrity, and DoD data may be compromised. OL 8 systems using encryption are required to use FIPS-compliant mechanisms for authenticating to cryptographic modules. Currently, Kerberos does not use FIPS 140-2 cryptography. FIPS 140-2 is the current standard for validating that mechanisms used to access cryptographic modules use authentication that meets DoD requirements. This allows for Security Levels 1, 2, 3, or 4 for use on a general-purpose computing system.
Checks: C-51980r779202_chk

Verify the krb5-workstation package has not been installed on the system with the following commands: If the system is a server or is using krb5-workstation-1.17-18.el8.x86_64 or newer, this is Not Applicable. $ sudo yum list installed krb5-workstation krb5-workstation.x86_64 1.17-9.el8 repository If the krb5-workstation package is installed and is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding.

Fix: F-51934r779203_fix

Document the krb5-workstation package with the ISSO as an operational requirement or remove it from the system with the following command: $ sudo yum remove krb5-workstation

b
The krb5-server package must not be installed on OL 8.
IA-7 - Medium - CCI-000803 - V-248547 - SV-248547r779207_rule
RMF Control
IA-7
Severity
Medium
CCI
CCI-000803
Version
OL08-00-010163
Vuln IDs
  • V-248547
Rule IDs
  • SV-248547r779207_rule
Unapproved mechanisms that are used for authentication to the cryptographic module are not verified and therefore cannot be relied on to provide confidentiality or integrity, and DoD data may be compromised. OL 8 systems using encryption are required to use FIPS-compliant mechanisms for authenticating to cryptographic modules. Currently, Kerberos does not use FIPS 140-2 cryptography. FIPS 140-2 is the current standard for validating that mechanisms used to access cryptographic modules use authentication that meets DoD requirements. This allows for Security Levels 1, 2, 3, or 4 for use on a general-purpose computing system.
Checks: C-51981r779205_chk

Verify the krb5-server package has not been installed on the system with the following commands: If the system is a workstation or is using krb5-server-1.17-18.el8.x86_64 or newer, this is Not Applicable $ sudo yum list installed krb5-server krb5-server.x86_64 1.17-9.el8 repository If the krb5-server package is installed and is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding.

Fix: F-51935r779206_fix

Document the krb5-server package with the ISSO as an operational requirement or remove it from the system with the following command: $ sudo yum remove krb5-server

b
OL 8 must use a Linux Security Module configured to enforce limits on system services.
SC-3 - Medium - CCI-001084 - V-248548 - SV-248548r779210_rule
RMF Control
SC-3
Severity
Medium
CCI
CCI-001084
Version
OL08-00-010170
Vuln IDs
  • V-248548
Rule IDs
  • SV-248548r779210_rule
Without verification of the security functions, security functions may not operate correctly and the failure may go unnoticed. Security function is defined as the hardware, software, and/or firmware of the information system responsible for enforcing the system security policy and supporting the isolation of code and data on which the protection is based. Security functionality includes but is not limited to establishing system accounts, configuring access authorizations (i.e., permissions, privileges), setting events to be audited, and setting intrusion detection parameters. This requirement applies to operating systems performing security function verification/testing and/or systems and environments that require this functionality.
Checks: C-51982r779208_chk

Verify the operating system verifies correct operation of all security functions. Check if "SELinux" is in "Enforcing" mode with the following command: $ getenforce Enforcing If "SELinux" is not in "Enforcing" mode, this is a finding.

Fix: F-51936r779209_fix

Configure OL 8 to verify correct operation of all security functions. Set "SELinux" to "Enforcing" mode by modifying the "/etc/selinux/config" file with the following line: SELINUX=enforcing A reboot is required for the changes to take effect.

a
OL 8 must have the "policycoreutils" package installed.
SC-3 - Low - CCI-001084 - V-248549 - SV-248549r779213_rule
RMF Control
SC-3
Severity
Low
CCI
CCI-001084
Version
OL08-00-010171
Vuln IDs
  • V-248549
Rule IDs
  • SV-248549r779213_rule
Without verification of the security functions, security functions may not operate correctly and the failure may go unnoticed. Security function is defined as the hardware, software, and/or firmware of the information system responsible for enforcing the system security policy and supporting the isolation of code and data on which the protection is based. Security functionality includes but is not limited to establishing system accounts, configuring access authorizations (i.e., permissions, privileges), setting events to be audited, and setting intrusion detection parameters.
Checks: C-51983r779211_chk

Verify the operating system has the "policycoreutils" package installed with the following command: $ sudo yum list installed policycoreutils policycoreutils.x86_64 2.9-3.el8 @anaconda If the "policycoreutils" package is not installed, this is a finding.

Fix: F-51937r779212_fix

Install the "policycoreutil" package, if it is not already installed, by running the following command: $ sudo yum install policycoreutils

b
A sticky bit must be set on all OL 8 public directories to prevent unauthorized and unintended information transferred via shared system resources.
SC-4 - Medium - CCI-001090 - V-248551 - SV-248551r779219_rule
RMF Control
SC-4
Severity
Medium
CCI
CCI-001090
Version
OL08-00-010190
Vuln IDs
  • V-248551
Rule IDs
  • SV-248551r779219_rule
Preventing unauthorized information transfers mitigates the risk of information, including encrypted representations of information, produced by the actions of prior users/roles (or the actions of processes acting on behalf of prior users/roles) from being available to any current users/roles (or current processes) that obtain access to shared system resources (e.g., registers, main memory, hard disks) after those resources have been released back to information systems. The control of information in shared resources is also commonly referred to as object reuse and residual information protection. This requirement generally applies to the design of an information technology product, but it can also apply to the configuration of particular information system components that are, or use, such products. This can be verified by acceptance/validation processes in DoD or other government agencies. There may be shared resources with configurable protections (e.g., files in storage) that may be assessed on specific information system components.
Checks: C-51985r779217_chk

Verify that all world-writable directories have the sticky bit set. Verify that all world-writable directories have the sticky bit set by running the following command: $ sudo find / -type d \( -perm -0002 -a ! -perm -1000 \) -print 2>/dev/null If any of the returned directories are world-writable and do not have the sticky bit set, this is a finding.

Fix: F-51939r779218_fix

Configure all world-writable directories to have the sticky bit set to prevent unauthorized and unintended information transferred via shared system resources. Set the sticky bit on all world-writable directories using the command, replace "[World-Writable Directory]" with any directory path missing the sticky bit: $ sudo chmod 1777 [World-Writable Directory]

b
OL 8 must be configured so that all network connections associated with SSH traffic terminate after becoming unresponsive.
MA-4 - Medium - CCI-000879 - V-248552 - SV-248552r917896_rule
RMF Control
MA-4
Severity
Medium
CCI
CCI-000879
Version
OL08-00-010200
Vuln IDs
  • V-248552
Rule IDs
  • SV-248552r917896_rule
Terminating an unresponsive SSH session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been left unattended. In addition, quickly terminating an idle SSH session will also free up resources committed by the managed network element. Terminating network connections associated with communications sessions includes, for example, de-allocating associated TCP/IP address/port pairs at the operating system level and de-allocating networking assignments at the application level if multiple application sessions are using a single operating system-level network connection. This does not mean that the operating system terminates all sessions or network access; it only ends the unresponsive session and releases the resources associated with that session. OL 8 uses "/etc/ssh/sshd_config" for configurations of OpenSSH. Within the "sshd_config", the product of the values of "ClientAliveInterval" and "ClientAliveCountMax" is used to establish the inactivity threshold. The "ClientAliveInterval" is a timeout interval in seconds after which if no data has been received from the client, sshd will send a message through the encrypted channel to request a response from the client. The "ClientAliveCountMax" is the number of client alive messages that may be sent without sshd receiving any messages back from the client. If this threshold is met, sshd will disconnect the client. For more information on these settings and others, refer to the sshd_config man pages. Satisfies: SRG-OS-000126-GPOS-00066, SRG-OS-000163-GPOS-00072, SRG-OS-000279-GPOS-00109
Checks: C-51986r917894_chk

Verify the SSH server automatically terminates a user session after the SSH client has become unresponsive. Check that the "ClientAliveCountMax" is set to "1" by running the following command: $ sudo grep -ir ClientAliveCountMax /etc/ssh/sshd_config* ClientAliveCountMax 1 If "ClientAliveCountMax" does not exist, does not have a product value of "1" in "/etc/ssh/sshd_config", or is commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-51940r917895_fix

Note: This setting must be applied in conjunction with OL08-00-010201 to function correctly. Configure the SSH server to terminate a user session automatically after the SSH client has become unresponsive. Modify or append the following line in the "/etc/ssh/sshd_config" file: ClientAliveCountMax 1 For the changes to take effect, the SSH daemon must be restarted. $ sudo systemctl restart sshd.service

b
OL 8 must be configured so that all network connections associated with SSH traffic are terminated after 10 minutes of becoming unresponsive.
MA-4 - Medium - CCI-000879 - V-248553 - SV-248553r917899_rule
RMF Control
MA-4
Severity
Medium
CCI
CCI-000879
Version
OL08-00-010201
Vuln IDs
  • V-248553
Rule IDs
  • SV-248553r917899_rule
Terminating an unresponsive SSH session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been left unattended. In addition, quickly terminating an idle SSH session will also free up resources committed by the managed network element. Terminating network connections associated with communications sessions includes, for example, de-allocating associated TCP/IP address/port pairs at the operating system level and de-allocating networking assignments at the application level if multiple application sessions are using a single operating system-level network connection. This does not mean that the operating system terminates all sessions or network access; it only ends the unresponsive session and releases the resources associated with that session. OL 8 uses "/etc/ssh/sshd_config" for configurations of OpenSSH. Within the "sshd_config", the product of the values of "ClientAliveInterval" and "ClientAliveCountMax" is used to establish the inactivity threshold. The "ClientAliveInterval" is a timeout interval in seconds after which if no data has been received from the client, sshd will send a message through the encrypted channel to request a response from the client. The "ClientAliveCountMax" is the number of client alive messages that may be sent without sshd receiving any messages back from the client. If this threshold is met, sshd will disconnect the client. For more information on these settings and others, refer to the sshd_config man pages. Satisfies: SRG-OS-000126-GPOS-00066, SRG-OS-000163-GPOS-00072, SRG-OS-000279-GPOS-00109
Checks: C-51987r917897_chk

Verify the SSH server automatically terminates a user session after the SSH client has been unresponsive for 10 minutes. Check that the "ClientAliveInterval" variable is set to a value of "600" or less by running the following command: $ sudo grep -ir ClientAliveInterval /etc/ssh/sshd_config* ClientAliveInterval 600 If "ClientAliveInterval" does not exist, does not have a product value of "600" or less in "/etc/ssh/sshd_config", or is commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-51941r917898_fix

Note: This setting must be applied in conjunction with OL08-00-010200 to function correctly. Configure the SSH server to terminate a user session automatically after the SSH client has been unresponsive for 10 minutes. Modify or append the following lines in the "/etc/ssh/sshd_config" file to have a product value of "600" or less: ClientAliveInterval 600 The SSH daemon must be restarted for changes to take effect. $ sudo systemctl restart sshd.service

b
The OL 8 "/var/log/messages" file must have mode 0640 or less permissive.
SI-11 - Medium - CCI-001314 - V-248554 - SV-248554r779228_rule
RMF Control
SI-11
Severity
Medium
CCI
CCI-001314
Version
OL08-00-010210
Vuln IDs
  • V-248554
Rule IDs
  • SV-248554r779228_rule
Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the OL 8 system or platform. Additionally, Personally Identifiable Information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements.
Checks: C-51988r779226_chk

Verify that the "/var/log/messages" file has mode "0640" or less permissive with the following command: $ sudo stat -c "%a %n" /var/log/messages 640 /var/log/messages If a value of "0640" or less permissive is not returned, this is a finding.

Fix: F-51942r779227_fix

Change the permissions of the file "/var/log/messages" to "0640" by running the following command: $ sudo chmod 0640 /var/log/messages

b
The OL 8 "/var/log/messages" file must be owned by root.
SI-11 - Medium - CCI-001314 - V-248555 - SV-248555r779231_rule
RMF Control
SI-11
Severity
Medium
CCI
CCI-001314
Version
OL08-00-010220
Vuln IDs
  • V-248555
Rule IDs
  • SV-248555r779231_rule
Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the OL 8 system or platform. Additionally, Personally Identifiable Information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements.
Checks: C-51989r779229_chk

Verify that the /var/log/messages file is owned by root with the following command: $ sudo stat -c "%U" /var/log/messages root If "root" is not returned as a result, this is a finding.

Fix: F-51943r779230_fix

Change the owner of the file /var/log/messages to root by running the following command: $ sudo chown root /var/log/messages

b
The OL 8 "/var/log/messages" file must be group-owned by root.
SI-11 - Medium - CCI-001314 - V-248556 - SV-248556r779234_rule
RMF Control
SI-11
Severity
Medium
CCI
CCI-001314
Version
OL08-00-010230
Vuln IDs
  • V-248556
Rule IDs
  • SV-248556r779234_rule
Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the OL 8 system or platform. Additionally, Personally Identifiable Information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements.
Checks: C-51990r779232_chk

Verify the "/var/log/messages" file is group-owned by root with the following command: $ sudo stat -c "%G" /var/log/messages root If "root" is not returned as a result, this is a finding.

Fix: F-51944r779233_fix

Change the group of the file "/var/log/messages" to "root" by running the following command: $ sudo chgrp root /var/log/messages

b
The OL 8 "/var/log" directory must have mode 0755 or less permissive.
SI-11 - Medium - CCI-001314 - V-248557 - SV-248557r779237_rule
RMF Control
SI-11
Severity
Medium
CCI
CCI-001314
Version
OL08-00-010240
Vuln IDs
  • V-248557
Rule IDs
  • SV-248557r779237_rule
Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the OL 8 system or platform. Additionally, Personally Identifiable Information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements.
Checks: C-51991r779235_chk

Verify that the "/var/log" directory has a mode of "0755" or less with the following command: $ sudo stat -c "%a %n" /var/log 755 /var/log If a value of "0755" or less permissive is not returned, this is a finding.

Fix: F-51945r779236_fix

Change the permissions of the directory "/var/log" to "0755" by running the following command: $ sudo chmod 0755 /var/log

b
The OL 8 "/var/log" directory must be owned by root.
SI-11 - Medium - CCI-001314 - V-248558 - SV-248558r779240_rule
RMF Control
SI-11
Severity
Medium
CCI
CCI-001314
Version
OL08-00-010250
Vuln IDs
  • V-248558
Rule IDs
  • SV-248558r779240_rule
Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the OL 8 system or platform. Additionally, Personally Identifiable Information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements.
Checks: C-51992r779238_chk

Verify the /var/log directory is owned by root with the following command: $ sudo stat -c "%U" /var/log root If "root" is not returned as a result, this is a finding.

Fix: F-51946r779239_fix

Change the owner of the directory /var/log to root by running the following command: $ sudo chown root /var/log

b
The OL 8 "/var/log" directory must be group-owned by root.
SI-11 - Medium - CCI-001314 - V-248559 - SV-248559r779243_rule
RMF Control
SI-11
Severity
Medium
CCI
CCI-001314
Version
OL08-00-010260
Vuln IDs
  • V-248559
Rule IDs
  • SV-248559r779243_rule
Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the OL 8 system or platform. Additionally, Personally Identifiable Information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements.
Checks: C-51993r779241_chk

Verify the "/var/log" directory is group-owned by root with the following command: $ sudo stat -c "%G" /var/log root If "root" is not returned as a result, this is a finding.

Fix: F-51947r779242_fix

Change the group of the directory "/var/log" to "root" by running the following command: $ sudo chgrp root /var/log

b
The OL 8 SSH daemon must be configured to use system-wide crypto policies.
AC-17 - Medium - CCI-001453 - V-248560 - SV-248560r877394_rule
RMF Control
AC-17
Severity
Medium
CCI
CCI-001453
Version
OL08-00-010287
Vuln IDs
  • V-248560
Rule IDs
  • SV-248560r877394_rule
Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DoD nonpublic information systems by an authorized user (or an information system) communicating through an external, non-organization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. OL 8 incorporates system-wide crypto policies by default. The SSH configuration file has no effect on the ciphers, MACs, or algorithms unless specifically defined in the /etc/sysconfig/sshd file. The employed algorithms can be viewed in the /etc/crypto-policies/back-ends/ directory.
Checks: C-51994r818612_chk

Verify that system-wide crypto policies are in effect: $ sudo grep -i CRYPTO_POLICY /etc/sysconfig/sshd # CRYPTO_POLICY= If the "CRYPTO_POLICY" is uncommented, this is a finding.

Fix: F-51948r818613_fix

Configure the OL 8 SSH daemon to use system-wide crypto policies by adding the following line to /etc/sysconfig/sshd: # CRYPTO_POLICY= A reboot is required for the changes to take effect.

b
The OL 8 SSH server must be configured to use only Message Authentication Codes (MACs) employing FIPS 140-2 validated cryptographic hash algorithms.
MA-4 - Medium - CCI-000877 - V-248561 - SV-248561r917902_rule
RMF Control
MA-4
Severity
Medium
CCI
CCI-000877
Version
OL08-00-010290
Vuln IDs
  • V-248561
Rule IDs
  • SV-248561r917902_rule
Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DoD nonpublic information systems by an authorized user (or an information system) communicating through an external, non-organization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography, enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. OL 8 incorporates system-wide crypto policies by default. The SSH configuration file has no effect on the ciphers, MACs, or algorithms unless specifically defined in the "/etc/sysconfig/sshd" file. The employed algorithms can be viewed in the "/etc/crypto-policies/back-ends/opensshserver.config" file. The system will attempt to use the first hash presented by the client that matches the server list. Listing the values "strongest to weakest" is a method to ensure the use of the strongest hash available to secure the SSH connection.
Checks: C-51995r917900_chk

Verify the SSH server is configured to use only MACs employing FIPS 140-2-approved algorithms with the following command: $ sudo grep -i macs /etc/crypto-policies/back-ends/opensshserver.config -oMACS=hmac-sha2-512,hmac-sha2-256,hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com If the MACs entries in the "opensshserver.config" file have any hashes other than shown here, the order differs from the example above, or they are missing or commented out, this is a finding.

Fix: F-51949r917901_fix

Configure the OL 8 SSH server to use only MACs employing FIPS 140-2 approved algorithms: Update the "/etc/crypto-policies/back-ends/opensshserver.config" file to include these MACs employing FIPS 140-2 approved algorithms: -oMACS=hmac-sha2-512,hmac-sha2-256,hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com A reboot is required for the changes to take effect.

b
The OL 8 SSH server must be configured to use only ciphers employing FIPS 140-2 validated cryptographic algorithms.
MA-4 - Medium - CCI-000877 - V-248562 - SV-248562r917905_rule
RMF Control
MA-4
Severity
Medium
CCI
CCI-000877
Version
OL08-00-010291
Vuln IDs
  • V-248562
Rule IDs
  • SV-248562r917905_rule
Unapproved mechanisms that are used for authentication to the cryptographic module are not verified and therefore cannot be relied on to provide confidentiality or integrity, and DoD data may be compromised. Operating systems using encryption are required to use FIPS-compliant mechanisms for authenticating to cryptographic modules. FIPS 140-2 is the current standard for validating that mechanisms used to access cryptographic modules use authentication that meets DoD requirements. This allows for Security Levels 1, 2, 3, or 4 for use on a general-purpose computing system. The system will attempt to use the first hash presented by the client that matches the server list. Listing the values "strongest to weakest" is a method to ensure the use of the strongest cipher available to secure the SSH connection.
Checks: C-51996r917903_chk

Verify the OL 8 SSH server is configured to use only ciphers employing FIPS 140-2 approved algorithms with the following command: $ sudo grep -i ciphers /etc/crypto-policies/back-ends/opensshserver.config CRYPTO_POLICY='-oCiphers=aes256-ctr,aes192-ctr,aes128-ctr,aes256-gcm@openssh.com,aes128-gcm@openssh.com' If the cipher entries in the "opensshserver.config" file have any ciphers other than shown here, the order differs from the example above, or they are missing or commented out, this is a finding.

Fix: F-51950r917904_fix

Configure the OL 8 SSH server to use only ciphers employing FIPS 140-2 approved algorithms: Update the "/etc/crypto-policies/back-ends/opensshserver.config" file to include these ciphers employing FIPS 140-2-approved algorithms: CRYPTO_POLICY='-oCiphers=aes256-ctr,aes192-ctr,aes128-ctr,aes256-gcm@openssh.com,aes128-gcm@openssh.com' A reboot is required for the changes to take effect.

a
The OL 8 SSH server must be configured to use strong entropy.
CM-6 - Low - CCI-000366 - V-248563 - SV-248563r779255_rule
RMF Control
CM-6
Severity
Low
CCI
CCI-000366
Version
OL08-00-010292
Vuln IDs
  • V-248563
Rule IDs
  • SV-248563r779255_rule
The most important characteristic of a random number generator is its randomness, namely its ability to deliver random numbers that are impossible to predict. Entropy in computer security is associated with the unpredictability of a source of randomness. The random source with high entropy tends to achieve a uniform distribution of random values. Random number generators are one of the most important building blocks of cryptosystems. The SSH implementation in OL 8 uses the OPENSSL library, which does not use high-entropy sources by default. By using the SSH_USE_STRONG_RNG environment variable, the OPENSSL random generator is reseeded from "/dev/random". This setting is not recommended on computers without the hardware random generator because insufficient entropy causes the connection to be blocked until enough entropy is available.
Checks: C-51997r779253_chk

Verify the operating system SSH server uses strong entropy with the following command: $ sudo grep -i ssh_use_strong_rng /etc/sysconfig/sshd SSH_USE_STRONG_RNG=32 If the "SSH_USE_STRONG_RNG" line does not equal "32" or is commented out or missing, this is a finding.

Fix: F-51951r779254_fix

Configure the operating system SSH server to use strong entropy. Add or modify the following line in the "/etc/sysconfig/sshd" file. SSH_USE_STRONG_RNG=32 The SSH service must be restarted for changes to take effect.

b
The OL 8 operating system must implement DoD-approved encryption in the OpenSSL package.
AC-17 - Medium - CCI-001453 - V-248564 - SV-248564r877394_rule
RMF Control
AC-17
Severity
Medium
CCI
CCI-001453
Version
OL08-00-010293
Vuln IDs
  • V-248564
Rule IDs
  • SV-248564r877394_rule
Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DoD nonpublic information systems by an authorized user (or an information system) communicating through an external, non-organization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography, enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. OL 8 incorporates system-wide crypto policies by default. The employed algorithms can be viewed in the "/etc/crypto-policies/back-ends/openssl.config" file.
Checks: C-51998r779256_chk

Verify the OpenSSL library is configured to use only ciphers employing FIPS 140-2-approved algorithms: Verify that system-wide crypto policies are in effect: $ sudo grep -i opensslcnf.config /etc/pki/tls/openssl.cnf .include /etc/crypto-policies/back-ends/opensslcnf.config If the "opensslcnf.config" is not defined in the "/etc/pki/tls/openssl.cnf" file, this is a finding. Verify which system-wide crypto policy is in use: $ sudo update-crypto-policies --show FIPS If the system-wide crypto policy is set to anything other than "FIPS", this is a finding.

Fix: F-51952r779257_fix

Configure the OL 8 OpenSSL library to use only ciphers employing FIPS 140-2-approved algorithms with the following command: $ sudo fips-mode-setup --enable A reboot is required for the changes to take effect.

b
The OL 8 operating system must implement DoD-approved TLS encryption in the OpenSSL package.
AC-17 - Medium - CCI-001453 - V-248565 - SV-248565r877394_rule
RMF Control
AC-17
Severity
Medium
CCI
CCI-001453
Version
OL08-00-010294
Vuln IDs
  • V-248565
Rule IDs
  • SV-248565r877394_rule
Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DoD nonpublic information systems by an authorized user (or an information system) communicating through an external, non-organization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography, enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. OL 8 incorporates system-wide crypto policies by default. The employed algorithms can be viewed in the "/etc/crypto-policies/back-ends/openssl.config" file. Satisfies: SRG-OS-000250-GPOS-00093, SRG-OS-000393-GPOS-00173, SRG-OS-000394-GPOS-00174, SRG-OS-000125-GPOS-00065
Checks: C-51999r818615_chk

Verify the OpenSSL library is configured to use only DoD-approved TLS encryption: For versions prior to crypto-policies-20210617-1.gitc776d3e.el8.noarch: $ sudo grep -i MinProtocol /etc/crypto-policies/back-ends/opensslcnf.config MinProtocol = TLSv1.2 If the "MinProtocol" is set to anything older than "TLSv1.2", this is a finding. For version crypto-policies-20210617-1.gitc776d3e.el8.noarch and newer: $ sudo grep -i MinProtocol /etc/crypto-policies/back-ends/opensslcnf.config TLS.MinProtocol = TLSv1.2 DTLS.MinProtocol = DTLSv1.2 If the "TLS.MinProtocol" is set to anything older than "TLSv1.2" or the "DTLS.MinProtocol" is set to anything older than "DTLSv1.2", this is a finding.

Fix: F-51953r818616_fix

Configure the OL 8 OpenSSL library to use only DoD-approved TLS encryption by editing the following line in the "/etc/crypto-policies/back-ends/opensslcnf.config" file: For versions prior to crypto-policies-20210617-1.gitc776d3e.el8.noarch: MinProtocol = TLSv1.2 For version crypto-policies-20210617-1.gitc776d3e.el8.noarch and newer: TLS.MinProtocol = TLSv1.2 DTLS.MinProtocol = DTLSv1.2 A reboot is required for the changes to take effect.

b
The OL 8 operating system must implement DoD-approved TLS encryption in the GnuTLS package.
AC-17 - Medium - CCI-001453 - V-248566 - SV-248566r877394_rule
RMF Control
AC-17
Severity
Medium
CCI
CCI-001453
Version
OL08-00-010295
Vuln IDs
  • V-248566
Rule IDs
  • SV-248566r877394_rule
Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Transport Layer Security (TLS) encryption is a required security setting as a number of known vulnerabilities have been reported against Secure Sockets Layer (SSL) and earlier versions of TLS. Encryption of private information is essential to ensuring data confidentiality. If private information is not encrypted, it can be intercepted and easily read by an unauthorized party. SQL Server must use a minimum of FIPS 140-2 approved TLS version 1.2, and all non-FIPS-approved SSL and TLS versions must be disabled. NIST SP 800-52 specifies the preferred configurations for government systems. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography, enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. The GnuTLS library offers an API to access secure communications protocols. SSLv2 is not available in the GnuTLS library. The OL 8 system-wide crypto policy defines employed algorithms in the "/etc/crypto-policies/back-ends/gnutls.config" file.
Checks: C-52000r818618_chk

Verify the GnuTLS library is configured to only allow DoD-approved SSL/TLS versions: $ sudo grep -io +vers.* /etc/crypto-policies/back-ends/gnutls.config +VERS-ALL:-VERS-DTLS0.9:-VERS-SSL3.0:-VERS-TLS1.0:-VERS-TLS1.1:-VERS-DTLS1.0:+COMP-NULL:%PROFILE_MEDIUM If the "gnutls.config" does not list "-VERS-DTLS0.9:-VERS-SSL3.0:-VERS-TLS1.0:-VERS-TLS1.1:-VERS-DTLS1.0" to disable unapproved SSL/TLS versions, this is a finding.

Fix: F-51954r779263_fix

Configure the OL 8 GnuTLS library to use only DoD-approved encryption by adding the following line to "/etc/crypto-policies/back-ends/gnutls.config": +VERS-ALL:-VERS-DTLS0.9:-VERS-SSL3.0:-VERS-TLS1.0:-VERS-TLS1.1:-VERS-DTLS1.0 A reboot is required for the changes to take effect.

b
OL 8 system commands must have mode 755 or less permissive.
CM-5 - Medium - CCI-001499 - V-248567 - SV-248567r818622_rule
RMF Control
CM-5
Severity
Medium
CCI
CCI-001499
Version
OL08-00-010300
Vuln IDs
  • V-248567
Rule IDs
  • SV-248567r818622_rule
If OL 8 were to allow any user to make changes to software libraries, those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to OL 8 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges. Only qualified and authorized individuals must be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications.
Checks: C-52001r818620_chk

Verify the system commands contained in the following directories have mode "755" or less permissive with the following command: $ sudo find -L /bin /sbin /usr/bin /usr/sbin /usr/local/bin /usr/local/sbin -perm /022 -exec ls -l {} \; If any system commands are found to be group-writable or world-writable, this is a finding.

Fix: F-51955r818621_fix

Configure the system commands to be protected from unauthorized access. Run the following command, replacing "[FILE]" with any system command with a mode more permissive than "755". $ sudo chmod 755 [FILE]

b
OL 8 system commands must be owned by root.
CM-5 - Medium - CCI-001499 - V-248568 - SV-248568r779270_rule
RMF Control
CM-5
Severity
Medium
CCI
CCI-001499
Version
OL08-00-010310
Vuln IDs
  • V-248568
Rule IDs
  • SV-248568r779270_rule
If OL 8 were to allow any user to make changes to software libraries, those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to OL 8 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges. Only qualified and authorized individuals must be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications.
Checks: C-52002r779268_chk

Verify the system commands contained in the following directories are owned by "root" with the following command: $ sudo find -L /bin /sbin /usr/bin /usr/sbin /usr/local/bin /usr/local/sbin ! -user root -exec ls -l {} \; If any system commands are returned, this is a finding.

Fix: F-51956r779269_fix

Configure the system commands to be protected from unauthorized access. Run the following command, replacing "[FILE]" with any system command file not owned by "root". $ sudo chown root [FILE]

b
OL 8 system commands must be group-owned by root or a system account.
CM-5 - Medium - CCI-001499 - V-248569 - SV-248569r818625_rule
RMF Control
CM-5
Severity
Medium
CCI
CCI-001499
Version
OL08-00-010320
Vuln IDs
  • V-248569
Rule IDs
  • SV-248569r818625_rule
If OL 8 were to allow any user to make changes to software libraries, those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to OL 8 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges. Only qualified and authorized individuals must be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications.
Checks: C-52003r818623_chk

Verify the system commands contained in the following directories are group-owned by "root" or a required system account, with the following command: $ sudo find -L /bin /sbin /usr/bin /usr/sbin /usr/local/bin /usr/local/sbin ! -group root -exec ls -l {} \; If any system commands are returned and is not group-owned by a required system account, this is a finding.

Fix: F-51957r818624_fix

Configure the system commands to be protected from unauthorized access. Run the following command, replacing "[FILE]" with any system command file not group-owned by "root" or a required system account. $ sudo chgrp root [FILE]

b
OL 8 library files must have mode 755 or less permissive.
CM-5 - Medium - CCI-001499 - V-248570 - SV-248570r818628_rule
RMF Control
CM-5
Severity
Medium
CCI
CCI-001499
Version
OL08-00-010330
Vuln IDs
  • V-248570
Rule IDs
  • SV-248570r818628_rule
If OL 8 were to allow any user to make changes to software libraries, those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to OL 8 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges. Only qualified and authorized individuals must be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications.
Checks: C-52004r818626_chk

Verify the system-wide shared library files contained in the following directories have mode "755" or less permissive with the following command: $ sudo find -L /lib /lib64 /usr/lib /usr/lib64 -perm /022 -type f -exec ls -l {} \; If any system-wide shared library file is found to be group-writable or world-writable, this is a finding.

Fix: F-51958r818627_fix

Configure the library files to be protected from unauthorized access. Run the following command, replacing "[FILE]" with any library file with a mode more permissive than 755. $ sudo chmod 755 [FILE]

b
OL 8 library files must be owned by root.
CM-5 - Medium - CCI-001499 - V-248571 - SV-248571r779279_rule
RMF Control
CM-5
Severity
Medium
CCI
CCI-001499
Version
OL08-00-010340
Vuln IDs
  • V-248571
Rule IDs
  • SV-248571r779279_rule
If OL 8 were to allow any user to make changes to software libraries, those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to OL 8 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges. Only qualified and authorized individuals must be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications.
Checks: C-52005r779277_chk

Verify the system-wide shared library files are owned by "root" with the following command: $ sudo find -L /lib /lib64 /usr/lib /usr/lib64 ! -user root -exec ls -l {} \; If any system-wide shared library file is returned, this is a finding.

Fix: F-51959r779278_fix

Configure the system-wide shared library files (/lib, /lib64, /usr/lib, and /usr/lib64) to be protected from unauthorized access. Run the following command, replacing "[FILE]" with any library file not owned by "root". $ sudo chown root [FILE]

b
OL 8 library files must be group-owned by root.
CM-5 - Medium - CCI-001499 - V-248572 - SV-248572r779282_rule
RMF Control
CM-5
Severity
Medium
CCI
CCI-001499
Version
OL08-00-010350
Vuln IDs
  • V-248572
Rule IDs
  • SV-248572r779282_rule
If OL 8 were to allow any user to make changes to software libraries, those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to OL 8 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges. Only qualified and authorized individuals must be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications.
Checks: C-52006r779280_chk

Verify the system-wide shared library files are group-owned by "root" with the following command: $ sudo find -L /lib /lib64 /usr/lib /usr/lib64 ! -group root -exec ls -l {} \; If any system-wide shared library file is returned, this is a finding.

Fix: F-51960r779281_fix

Configure the system-wide shared library files (/lib, /lib64, /usr/lib, and /usr/lib64) to be protected from unauthorized access. Run the following command, replacing "[FILE]" with any library file not group-owned by "root". $ sudo chgrp root [FILE]

b
The OL 8 file integrity tool must notify the System Administrator (SA) when changes to the baseline configuration or anomalies in the operation of any security functions are discovered within an organizationally defined frequency.
CM-3 - Medium - CCI-001744 - V-248573 - SV-248573r902806_rule
RMF Control
CM-3
Severity
Medium
CCI
CCI-001744
Version
OL08-00-010360
Vuln IDs
  • V-248573
Rule IDs
  • SV-248573r902806_rule
Unauthorized changes to the baseline configuration could make the system vulnerable to various attacks or allow unauthorized access to the operating system. Changes to operating system configurations can have unintended side effects, some of which may be relevant to security. Detecting such changes and providing an automated response can help avoid unintended, negative consequences that could ultimately affect the security state of the operating system. The operating system's Information System Security Manager (ISSM)/Information System Security Officer (ISSO) and SAs must be notified via email and/or monitoring system trap when there is an unauthorized modification of a configuration item. Notifications provided by information systems include messages to local computer consoles and/or hardware indications, such as lights. This capability must take into account operational requirements for availability for selecting an appropriate response. The organization may choose to shut down or restart the information system upon security function anomaly detection. OL 8 comes with many optional software packages, including the file integrity tool Advanced Intrusion Detection Environment (AIDE). This requirement assumes the use of AIDE; however, a different tool may be used if the requirements are met. Note that AIDE does not have a configuration that will send a notification, so a cron job is recommended that uses the mail application on the system to email the results of the file integrity check. Satisfies: SRG-OS-000363-GPOS-00150, SRG-OS-000446-GPOS-00200, SRG-OS-000447-GPOS-00201
Checks: C-52007r902804_chk

Verify the operating system routinely checks the baseline configuration for unauthorized changes and notifies the SA when anomalies in the operation of any security functions are discovered. Check that OL 8 routinely executes a file integrity scan for changes to the system baseline. The command used in the example will use a daily occurrence. Check the cron directories for scripts controlling the execution and notification of results of the file integrity application. For example, if AIDE is installed on the system, use the following commands: $ sudo ls -al /etc/cron.* | grep aide -rwxr-xr-x 1 root root 29 Nov 22 2015 aide $ sudo grep aide /etc/crontab /var/spool/cron/root /etc/crontab: 30 04 * * * /root/aide /var/spool/cron/root: 30 04 * * * /root/aide $ sudo more /etc/cron.daily/aide #!/bin/bash /usr/sbin/aide --check | /bin/mail -s "$HOSTNAME - Daily AIDE integrity check run" root@example_server_name.mil If the file integrity application does not exist, a script file controlling the execution of the file integrity application does not exist, or the file integrity application does not notify designated personnel of changes, this is a finding.

Fix: F-51961r902805_fix

Configure the file integrity tool to run automatically on the system at least weekly and to notify designated personnel if baseline configurations are changed in an unauthorized manner. The AIDE tool can be configured to email designated personnel with the use of the cron system. The following example output is generic. It will set cron to run AIDE daily and to send an email at the completion of the analysis. $ sudo more /etc/cron.daily/aide #!/bin/bash /usr/sbin/aide --check |/bin/mail -s "$HOSTNAME - Daily AIDE integrity check run" root@example_server_name.mil Note: Per requirement OL08-00-010358, the "mailx" package must be installed on the system to enable email functionality.

c
YUM must be configured to prevent the installation of patches, service packs, device drivers, or OL 8 system components that have not been digitally signed using a certificate that is recognized and approved by the organization.
CM-5 - High - CCI-001749 - V-248574 - SV-248574r877463_rule
RMF Control
CM-5
Severity
High
CCI
CCI-001749
Version
OL08-00-010370
Vuln IDs
  • V-248574
Rule IDs
  • SV-248574r877463_rule
Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. Accordingly, patches, service packs, device drivers, or operating system components must be signed with a certificate recognized and approved by the organization. Verifying the authenticity of the software prior to installation validates the integrity of the patch or upgrade received from a vendor. This verifies the software has not been tampered with and that it has been provided by a trusted vendor. Self-signed certificates are disallowed by this requirement. The operating system should not have to verify the software again. This requirement does not mandate DoD certificates for this purpose; however, the certificate used to verify the software must be from an approved Certificate Authority (CA).
Checks: C-52008r779286_chk

Check that YUM verifies the signature of packages from a repository prior to install with the following command: $ sudo grep gpgcheck /etc/yum.repos.d/*.repo gpgcheck=1 If "gpgcheck" is not set to "1", or if options are missing or commented out, ask the System Administrator how the certificates for patches and other operating system components are verified. If there is no process to validate certificates that is approved by the organization, this is a finding.

Fix: F-51962r779287_fix

Configure OL 8 to verify the signature of packages from a repository prior to install by setting the following option in the "/etc/yum.repos.d/[your_repo_name].repo" file: gpgcheck=1

c
OL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization.
CM-5 - High - CCI-001749 - V-248575 - SV-248575r877463_rule
RMF Control
CM-5
Severity
High
CCI
CCI-001749
Version
OL08-00-010371
Vuln IDs
  • V-248575
Rule IDs
  • SV-248575r877463_rule
Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. Accordingly, patches, service packs, device drivers, or operating system components must be signed with a certificate recognized and approved by the organization. Verifying the authenticity of the software prior to installation validates the integrity of the patch or upgrade received from a vendor. This verifies the software has not been tampered with and that it has been provided by a trusted vendor. Self-signed certificates are disallowed by this requirement. The operating system should not have to verify the software again. This requirement does not mandate DoD certificates for this purpose; however, the certificate used to verify the software must be from an approved Certificate Authority (CA).
Checks: C-52009r779289_chk

Verify the operating system prevents the installation of patches, service packs, device drivers, or operating system components from a repository without verification that they have been digitally signed using a certificate that is recognized and approved by the organization. Check if YUM is configured to perform a signature check on local packages with the following command: $ sudo grep -i localpkg_gpgcheck /etc/dnf/dnf.conf localpkg_gpgcheck =True If "localpkg_gpgcheck" is not set to either "1", "True", or "yes", commented out, or is missing from "/etc/dnf/dnf.conf", this is a finding.

Fix: F-51963r779290_fix

Configure the operating system to remove all software components after updated versions have been installed. Set the "localpkg_gpgcheck" option to "True" in the "/etc/dnf/dnf.conf" file: localpkg_gpgcheck=True

b
OL 8 must prevent the loading of a new kernel for later execution.
CM-5 - Medium - CCI-001749 - V-248576 - SV-248576r917907_rule
RMF Control
CM-5
Severity
Medium
CCI
CCI-001749
Version
OL08-00-010372
Vuln IDs
  • V-248576
Rule IDs
  • SV-248576r917907_rule
Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. Disabling "kexec_load" prevents an unsigned kernel image (that could be a windows kernel or modified vulnerable kernel) from being loaded. Kexec can be used to subvert the entire secureboot process and should be avoided at all costs, especially since it can load unsigned kernel images. The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf
Checks: C-52010r917906_chk

Note: For OL 8 systems using the Oracle Unbreakable Enterprise Kernel (UEK) Release 6 or above and with secureboot enabled, this requirement is not applicable. Verify the operating system is configured to disable kernel image loading with the following commands. Check the status of the "kernel.kexec_load_disabled" kernel parameter: $ sudo sysctl kernel.kexec_load_disabled kernel.kexec_load_disabled = 1 If "kernel.kexec_load_disabled" is not set to "1" or is missing, this is a finding. Check that the configuration files are present to enable this kernel parameter: $ sudo grep -r kernel.kexec_load_disabled /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf:kernel.kexec_load_disabled = 1 If "kernel.kexec_load_disabled" is not set to "1" or is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-51964r858608_fix

Configure OL 8 to disable kernel image loading. Add or edit the following line in a system configuration file in the "/etc/sysctl.d/" directory: kernel.kexec_load_disabled = 1 Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf Load settings from all system configuration files with the following command: $ sudo sysctl --system

b
OL 8 must enable kernel parameters to enforce Discretionary Access Control (DAC) on symlinks.
AC-3 - Medium - CCI-002165 - V-248577 - SV-248577r860911_rule
RMF Control
AC-3
Severity
Medium
CCI
CCI-002165
Version
OL08-00-010373
Vuln IDs
  • V-248577
Rule IDs
  • SV-248577r860911_rule
DAC is based on the notion that individual users are "owners" of objects and therefore have discretion over who should be authorized to access the object and in which mode (e.g., read or write). Ownership is usually acquired as a consequence of creating the object or via specified ownership assignment. DAC allows the owner to determine who will have access to objects they control. An example of DAC includes user-controlled file permissions. When DAC policies are implemented, subjects are not constrained as to what actions they can take with information for which they have already been granted access. Thus, subjects that have been granted access to information are not prevented from passing (i.e., the subjects have the discretion to pass) the information to other subjects or objects. A subject that is constrained in its operation by Mandatory Access Control (MAC) policies is still able to operate under the less rigorous constraints of this requirement. Therefore, while MAC imposes constraints preventing a subject from passing information to another subject operating at a different sensitivity level, this requirement permits the subject to pass the information to any subject at the same sensitivity level. The policy is bounded by the information system boundary. Once the information is passed outside the control of the information system, additional means may be required to ensure the constraints remain in effect. While the older, more traditional definitions of DAC require identity-based access control, that limitation is not required for this use of DAC. By enabling the "fs.protected_symlinks" kernel parameter, symbolic links are permitted to be followed only when outside a sticky world-writable directory, or when the UID of the link and follower match, or when the directory owner matches the symlink's owner. Disallowing such symlinks helps mitigate vulnerabilities based on insecure file system accessed by privileged programs, avoiding an exploitation vector exploiting unsafe use of open() or creat(). The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf
Checks: C-52011r858610_chk

Verify the operating system is configured to enable DAC on symlinks with the following commands. Check the status of the "fs.protected_symlinks" kernel parameter: $ sudo sysctl fs.protected_symlinks fs.protected_symlinks = 1 If "fs.protected_symlinks" is not set to "1" or is missing, this is a finding. Check that the configuration files are present to enable this kernel parameter: $ sudo grep -r fs.protected_symlinks /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf:fs.protected_symlinks = 1 If "fs.protected_symlinks" is not set to "1" or is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-51965r858611_fix

Configure OL 8 to enable DAC on symlinks. Add or edit the following line in a system configuration file in the "/etc/sysctl.d/" directory: fs.protected_symlinks = 1 Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf Load settings from all system configuration files with the following command: $ sudo sysctl --system

b
OL 8 must enable kernel parameters to enforce Discretionary Access Control (DAC) on hardlinks.
AC-3 - Medium - CCI-002165 - V-248578 - SV-248578r860912_rule
RMF Control
AC-3
Severity
Medium
CCI
CCI-002165
Version
OL08-00-010374
Vuln IDs
  • V-248578
Rule IDs
  • SV-248578r860912_rule
DAC is based on the notion that individual users are "owners" of objects and therefore have discretion over who should be authorized to access the object and in which mode (e.g., read or write). Ownership is usually acquired as a consequence of creating the object or via specified ownership assignment. DAC allows the owner to determine who will have access to objects they control. An example of DAC includes user-controlled file permissions. When DAC policies are implemented, subjects are not constrained as to what actions they can take with information for which they have already been granted access. Thus, subjects that have been granted access to information are not prevented from passing (i.e., the subjects have the discretion to pass) the information to other subjects or objects. A subject that is constrained in its operation by Mandatory Access Control (MAC) policies is still able to operate under the less rigorous constraints of this requirement. Therefore, while MAC imposes constraints preventing a subject from passing information to another subject operating at a different sensitivity level, this requirement permits the subject to pass the information to any subject at the same sensitivity level. The policy is bounded by the information system boundary. Once the information is passed outside the control of the information system, additional means may be required to ensure the constraints remain in effect. While the older, more traditional definitions of DAC require identity-based access control, that limitation is not required for this use of DAC. By enabling the "fs.protected_hardlinks" kernel parameter, users can no longer create soft or hard links to files they do not own. Disallowing such hardlinks mitigate vulnerabilities based on insecure file system accessed by privileged programs, avoiding an exploitation vector exploiting unsafe use of open() or creat(). The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf
Checks: C-52012r858613_chk

Verify the operating system is configured to enable DAC on hardlinks with the following commands. Check the status of the "fs.protected_hardlinks" kernel parameter: $ sudo sysctl fs.protected_hardlinks fs.protected_hardlinks = 1 If "fs.protected_hardlinks" is not set to "1" or is missing, this is a finding. Check that the configuration files are present to enable this kernel parameter: $ sudo grep -r fs.protected_hardlinks /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf:fs.protected_hardlinks = 1 If "fs.protected_hardlinks" is not set to "1" or is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-51966r858614_fix

Configure OL 8 to enable DAC on hardlinks. Add or edit the following line in a system configuration file in the "/etc/sysctl.d/" directory: fs.protected_hardlinks = 1 Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf Load settings from all system configuration files with the following command: $ sudo sysctl --system

a
OL 8 must restrict access to the kernel message buffer.
SC-4 - Low - CCI-001090 - V-248579 - SV-248579r858617_rule
RMF Control
SC-4
Severity
Low
CCI
CCI-001090
Version
OL08-00-010375
Vuln IDs
  • V-248579
Rule IDs
  • SV-248579r858617_rule
Preventing unauthorized information transfers mitigates the risk of information, including encrypted representations of information, produced by the actions of prior users/roles (or the actions of processes acting on behalf of prior users/roles) from being available to any current users/roles (or current processes) that obtain access to shared system resources (e.g., registers, main memory, hard disks) after those resources have been released back to information systems. The control of information in shared resources is also commonly referred to as object reuse and residual information protection. This requirement generally applies to the design of an information technology product, but it can also apply to the configuration of particular information system components that are, or use, such products. This can be verified by acceptance/validation processes in DoD or other government agencies. There may be shared resources with configurable protections (e.g., files in storage) that may be assessed on specific information system components. Restricting access to the kernel message buffer limits access to only root. This prevents attackers from gaining additional system information as a non-privileged user. The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf
Checks: C-52013r833200_chk

Verify the operating system is configured to restrict access to the kernel message buffer with the following commands. Check the status of the "kernel.dmesg_restrict" kernel parameter: $ sudo sysctl kernel.dmesg_restrict kernel.dmesg_restrict = 1 If "kernel.dmesg_restrict" is not set to "1" or is missing, this is a finding. Check that the configuration files are present to enable this kernel parameter: $ sudo grep -r kernel.dmesg_restrict /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf:kernel.dmesg_restrict = 1 If "kernel.dmesg_restrict" is not set to "1" or is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-51967r858616_fix

Configure OL 8 to restrict access to the kernel message buffer. Add or edit the following line in a system configuration file in the "/etc/sysctl.d/" directory: kernel.dmesg_restrict = 1 Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf Load settings from all system configuration files with the following command: $ sudo sysctl --system

a
OL 8 must prevent kernel profiling by unprivileged users.
SC-4 - Low - CCI-001090 - V-248580 - SV-248580r858619_rule
RMF Control
SC-4
Severity
Low
CCI
CCI-001090
Version
OL08-00-010376
Vuln IDs
  • V-248580
Rule IDs
  • SV-248580r858619_rule
Preventing unauthorized information transfers mitigates the risk of information, including encrypted representations of information, produced by the actions of prior users/roles (or the actions of processes acting on behalf of prior users/roles) from being available to any current users/roles (or current processes) that obtain access to shared system resources (e.g., registers, main memory, hard disks) after those resources have been released back to information systems. The control of information in shared resources is also commonly referred to as object reuse and residual information protection. This requirement generally applies to the design of an information technology product, but it can also apply to the configuration of particular information system components that are, or use, such products. This can be verified by acceptance/validation processes in DoD or other government agencies. There may be shared resources with configurable protections (e.g., files in storage) that may be assessed on specific information system components. Setting the "kernel.perf_event_paranoid" kernel parameter to "2" prevents attackers from gaining additional system information as a non-privileged user. The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf
Checks: C-52014r833202_chk

Verify the operating system is configured to prevent kernel profiling by unprivileged users with the following commands. Check the status of the "kernel.perf_event_paranoid" kernel parameter: $ sudo sysctl kernel.perf_event_paranoid kernel.perf_event_paranoid = 2 If "kernel.perf_event_paranoid" is not set to "2" or is missing, this is a finding. Check that the configuration files are present to enable this kernel parameter: $ sudo grep -r kernel.perf_event_paranoid /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf:kernel.perf_event_paranoid = 2 If "kernel.perf_event_paranoid" is not set to "2" or is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-51968r858618_fix

Configure OL 8 to prevent kernel profiling by unprivileged users. Add or edit the following line in a system configuration file in the "/etc/sysctl.d/" directory: kernel.perf_event_paranoid = 2 Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf Load settings from all system configuration files with the following command: $ sudo sysctl --system

b
OL 8 must require users to provide a password for privilege escalation.
IA-11 - Medium - CCI-002038 - V-248581 - SV-248581r860915_rule
RMF Control
IA-11
Severity
Medium
CCI
CCI-002038
Version
OL08-00-010380
Vuln IDs
  • V-248581
Rule IDs
  • SV-248581r860915_rule
Without reauthentication, users may access resources or perform tasks for which they do not have authorization. When operating systems provide the capability to escalate a functional capability, it is critical the user reauthenticate. Satisfies: SRG-OS-000373-GPOS-00156, SRG-OS-000373-GPOS-00157, SRG-OS-000373-GPOS-00158
Checks: C-52015r860913_chk

Verify that "/etc/sudoers" has no occurrences of "NOPASSWD". Check that the "/etc/sudoers" file has no occurrences of "NOPASSWD" by running the following command: $ sudo grep -ir nopasswd /etc/sudoers /etc/sudoers.d %admin ALL=(ALL) NOPASSWD: ALL If any occurrences of "NOPASSWD" are returned from the command and have not been documented with the ISSO as an organizationally defined administrative group using MFA, this is a finding.

Fix: F-51969r860914_fix

Configure the operating system to require users to supply a password for privilege escalation. Check the configuration of the "/etc/sudoers" file with the following command: $ sudo visudo Remove any occurrences of "NOPASSWD" tags in the file. Check the configuration of the /etc/sudoers.d/* files with the following command: $ sudo grep -ir nopasswd /etc/sudoers.d Remove any occurrences of "NOPASSWD" tags in the file.

b
OL 8 must require users to reauthenticate for privilege escalation and changing roles.
IA-11 - Medium - CCI-002038 - V-248582 - SV-248582r880551_rule
RMF Control
IA-11
Severity
Medium
CCI
CCI-002038
Version
OL08-00-010381
Vuln IDs
  • V-248582
Rule IDs
  • SV-248582r880551_rule
Without reauthentication, users may access resources or perform tasks for which they do not have authorization. When operating systems provide the capability to escalate a functional capability, it is critical the user reauthenticate. Satisfies: SRG-OS-000373-GPOS-00156, SRG-OS-000373-GPOS-00157, SRG-OS-000373-GPOS-00158
Checks: C-52016r880550_chk

Verify that the "/etc/sudoers" file has no occurrences of "!authenticate" by running the following command: $ sudo grep -Ei !authenticate /etc/sudoers /etc/sudoers.d/* If any occurrences of "!authenticate" return from the command, this is a finding.

Fix: F-51970r779311_fix

Remove any occurrence of "!authenticate" found in the "/etc/sudoers" file or files in the "/etc/sudoers.d" directory.

b
OL 8 must restrict privilege elevation to authorized personnel.
CM-6 - Medium - CCI-000366 - V-248583 - SV-248583r779315_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010382
Vuln IDs
  • V-248583
Rule IDs
  • SV-248583r779315_rule
The sudo command allows a user to execute programs with elevated (administrator) privileges. It prompts the user for their password and confirms your request to execute a command by checking a file, called sudoers. If the "sudoers" file is not configured correctly, any user defined on the system can initiate privileged actions on the target system.
Checks: C-52017r779313_chk

Verify the "sudoers" file restricts sudo access to authorized personnel. $ sudo grep -iw 'ALL' /etc/sudoers /etc/sudoers.d/* If the either of the following entries are returned, this is a finding: ALL ALL=(ALL) ALL ALL ALL=(ALL:ALL) ALL

Fix: F-51971r779314_fix

Remove the following entries from the sudoers file: ALL ALL=(ALL) ALL ALL ALL=(ALL:ALL) ALL

b
OL 8 must use the invoking user's password for privilege escalation when using "sudo".
CM-6 - Medium - CCI-000366 - V-248584 - SV-248584r880554_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010383
Vuln IDs
  • V-248584
Rule IDs
  • SV-248584r880554_rule
The sudoers security policy requires that users authenticate themselves before they can use sudo. When sudoers requires authentication, it validates the invoking user's credentials. If the rootpw, targetpw, or runaspw flags are defined and not disabled, by default the operating system will prompt the invoking user for the "root" user password. For more information on each of the listed configurations, reference the sudoers(5) manual page.
Checks: C-52018r880552_chk

Verify that the sudoers security policy is configured to use the invoking user's password for privilege escalation. $ sudo grep -Eir '(rootpw|targetpw|runaspw)' /etc/sudoers /etc/sudoers.d* | grep -v '#' /etc/sudoers:Defaults !targetpw /etc/sudoers:Defaults !rootpw /etc/sudoers:Defaults !runaspw If conflicting results are returned, this is a finding. If "Defaults !targetpw" is not defined, this is a finding. If "Defaults !rootpw" is not defined, this is a finding. If "Defaults !runaspw" is not defined, this is a finding.

Fix: F-51972r880553_fix

Define the following in the Defaults section of the /etc/sudoers file or a configuration file in the /etc/sudoers.d/ directory: Defaults !targetpw Defaults !rootpw Defaults !runaspw Remove any configurations that conflict with the above from the following locations: /etc/sudoers /etc/sudoers.d/

b
OL 8 must require re-authentication when using the "sudo" command.
IA-11 - Medium - CCI-002038 - V-248585 - SV-248585r880557_rule
RMF Control
IA-11
Severity
Medium
CCI
CCI-002038
Version
OL08-00-010384
Vuln IDs
  • V-248585
Rule IDs
  • SV-248585r880557_rule
Without re-authentication, users may access resources or perform tasks for which they do not have authorization. When operating systems provide the capability to escalate a functional capability, it is critical the organization requires the user to re-authenticate when using the "sudo" command. If the value is set to an integer less than 0, the user's time stamp will not expire and the user will not have to re-authenticate for privileged actions until the user's session is terminated. Satisfies: SRG-OS-000373-GPOS-00156, SRG-OS-000373-GPOS-00157, SRG-OS-000373-GPOS-00158
Checks: C-52019r880555_chk

Verify the operating system requires re-authentication when using the "sudo" command to elevate privileges. $ sudo grep -Eir 'timestamp_timeout' /etc/sudoers /etc/sudoers.d* /etc/sudoers:Defaults timestamp_timeout=0 If conflicting results are returned, this is a finding. If "timestamp_timeout" is set to a negative number, is commented out, or no results are returned, this is a finding.

Fix: F-51973r880556_fix

Configure the "sudo" command to require re-authentication. Edit the /etc/sudoers file: $ sudo visudo Add or modify the following line: Defaults timestamp_timeout=[value] Note: The "[value]" must be a number that is greater than or equal to "0". Remove any duplicate or conflicting lines from /etc/sudoers and /etc/sudoers.d/ files.

a
OL 8 must have the package required for multifactor authentication installed.
IA-2 - Low - CCI-001948 - V-248586 - SV-248586r853767_rule
RMF Control
IA-2
Severity
Low
CCI
CCI-001948
Version
OL08-00-010390
Vuln IDs
  • V-248586
Rule IDs
  • SV-248586r853767_rule
Using an authentication device, such as a DoD Common Access Card (CAC) or token that is separate from the information system, ensures that even if the information system is compromised, credentials stored on the authentication device will not be affected. Multifactor solutions that require devices separate from information systems gaining access include, for example, hardware tokens providing time-based or challenge-response authenticators and smart cards such as the U.S. Government Personal Identity Verification (PIV) card and the DoD CAC. A privileged account is defined as an information system account with authorizations of a privileged user. Remote access is access to DoD nonpublic information systems by an authorized user (or an information system) communicating through an external, non-organization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. This requirement only applies to components where this is specific to the function of the device or has the concept of an organizational user (e.g., VPN, proxy capability). This does not apply to authentication for the purpose of configuring the device itself (management).
Checks: C-52020r779322_chk

Verify the operating system has the package required for multifactor authentication installed with the following command: $ sudo yum list installed openssl-pkcs11 openssl-pkcs11.x86_64 0.4.8-2.el8 @anaconda If the "openssl-pkcs11" package is not installed, ask the administrator to indicate what type of multifactor authentication is being used and what packages are installed to support it. If there is no evidence of multifactor authentication being used, this is a finding.

Fix: F-51974r779323_fix

Configure OL 8 to implement multifactor authentication by installing the required package with the following command: $ sudo yum install openssl-pkcs11

b
OL 8 must implement certificate status checking for multifactor authentication.
IA-2 - Medium - CCI-001948 - V-248587 - SV-248587r860917_rule
RMF Control
IA-2
Severity
Medium
CCI
CCI-001948
Version
OL08-00-010400
Vuln IDs
  • V-248587
Rule IDs
  • SV-248587r860917_rule
Using an authentication device, such as a DoD Common Access Card (CAC) or token that is separate from the information system, ensures that even if the information system is compromised, credentials stored on the authentication device will not be affected. Multifactor solutions that require devices separate from information systems gaining access include, for example, hardware tokens providing time-based or challenge-response authenticators and smart cards such as the U.S. Government Personal Identity Verification (PIV) card and the DoD CAC. OL 8 includes multiple options for configuring certificate status checking but for this requirement focuses on the system security services daemon (sssd). By default, sssd performs Online Certificate Status Protocol (OCSP) checking and certificate verification using a sha256 digest function. Satisfies: SRG-OS-000375-GPOS-00160, SRG-OS-000377-GPOS-00162
Checks: C-52021r858603_chk

Verify the operating system implements certificate status checking for multifactor authentication. Note: If the System Administrator demonstrates the use of an approved alternate multifactor authentication method, this requirement is not applicable. Determine if Online Certificate Status Protocol (OCSP) is enabled and using the proper digest value on the system with the following command: $ sudo grep certificate_verification /etc/sssd/sssd.conf /etc/sssd/conf.d/*.conf | grep -v "^#" certificate_verification = ocsp_dgst=sha1 If the certificate_verification line is missing from the [sssd] section, or is missing "ocsp_dgst=sha1", ask the administrator to indicate what type of multifactor authentication is being used and how the system implements certificate status checking. If there is no evidence of certificate status checking being used, this is a finding.

Fix: F-51975r818643_fix

Configure OL 8 to implement certificate status checking for multifactor authentication. Review the "/etc/sssd/sssd.conf" file to determine if the system is configured to prevent OCSP or certificate verification. Add the following line to the [sssd] section of the "/etc/sssd/sssd.conf" file: certificate_verification = ocsp_dgst=sha1 The "sssd" service must be restarted for the changes to take effect. To restart the "sssd" service, run the following command: $ sudo systemctl restart sssd.service

b
OL 8 must accept Personal Identity Verification (PIV) credentials.
IA-2 - Medium - CCI-001953 - V-248588 - SV-248588r853769_rule
RMF Control
IA-2
Severity
Medium
CCI
CCI-001953
Version
OL08-00-010410
Vuln IDs
  • V-248588
Rule IDs
  • SV-248588r853769_rule
The use of PIV credentials facilitates standardization and reduces the risk of unauthorized access. The DoD has mandated the use of the Common Access Card (CAC) to support identity management and personal authentication for systems covered under Homeland Security Presidential Directive (HSPD) 12, as well as making the CAC a primary component of layered protection for national security systems.
Checks: C-52022r779328_chk

Verify OL 8 accepts PIV credentials. Check that the "opensc" package is installed on the system with the following command: $ sudo yum list installed opensc opensc.x86_64 0.19.0-5.el8 @anaconda Check that "opensc" accepts PIV cards with the following command: $ sudo opensc-tool --list-drivers | grep -i piv PIV-II Personal Identity Verification Card If the "opensc" package is not installed and the "opensc-tool" driver list does not include "PIV-II", this is a finding.

Fix: F-51976r779329_fix

Configure OL 8 to accept PIV credentials. Install the "opensc" package using the following command: $ sudo yum install opensc

b
OL 8 must implement non-executable data to protect its memory from unauthorized code execution.
SI-16 - Medium - CCI-002824 - V-248589 - SV-248589r853770_rule
RMF Control
SI-16
Severity
Medium
CCI
CCI-002824
Version
OL08-00-010420
Vuln IDs
  • V-248589
Rule IDs
  • SV-248589r853770_rule
Some adversaries launch attacks with the intent of executing code in non-executable regions of memory or in memory locations that are prohibited. Security safeguards employed to protect memory include, for example, data execution prevention and address space layout randomization. Data execution prevention safeguards can be either hardware-enforced or software-enforced, with hardware providing the greater strength of mechanism. Examples of attacks are buffer overflow attacks.
Checks: C-52023r779331_chk

Verify the NX (no-execution) bit flag is set on the system with the following commands: $ sudo dmesg | grep NX [ 0.000000] NX (Execute Disable) protection: active If "dmesg" does not show "NX (Execute Disable) protection" active, check the "cpuinfo" settings with the following command: $ sudo less /proc/cpuinfo | grep -i flags flags : fpu vme de pse tsc ms nx rdtscp lm constant_tsc If "flags" does not contain the "nx" flag, this is a finding.

Fix: F-51977r779332_fix

Enable the NX bit execute protection in the system BIOS.

b
OL 8 must clear the page allocator to prevent use-after-free attacks.
SC-3 - Medium - CCI-001084 - V-248590 - SV-248590r779336_rule
RMF Control
SC-3
Severity
Medium
CCI
CCI-001084
Version
OL08-00-010421
Vuln IDs
  • V-248590
Rule IDs
  • SV-248590r779336_rule
Adversaries may launch attacks with the intent of executing code in non-executable regions of memory or in memory locations that are prohibited. Security safeguards employed to protect memory include, for example, data execution prevention and address space layout randomization. Data execution prevention safeguards can be either hardware-enforced or software-enforced with hardware providing the greater strength of mechanism. Poisoning writes an arbitrary value to freed pages, so any modification or reference to that page after being freed or before being initialized will be detected and prevented. This prevents many types of use-after-free vulnerabilities at little performance cost. Also prevents leak of data and detection of corrupted memory.
Checks: C-52024r779334_chk

Verify that GRUB 2 is configured to enable page poisoning to mitigate use-after-free vulnerabilities with the following commands: $ sudo grub2-editenv list | grep page_poison kernelopts=root=/dev/mapper/ol-root ro crashkernel=auto resume=/dev/mapper/ol-swap rd.lvm.lv=ol/root rd.lvm.lv=ol/swap rhgb quiet fips=1 page_poison=1 vsyscall=none audit=1 audit_backlog_limit=8192 boot=UUID=8d171156-cd61-421c-ba41-1c021ac29e82 If "page_poison" is not set to "1" or is missing, this is a finding. Check that page poisoning is enabled by default to persist in kernel updates: $ sudo grep page_poison /etc/default/grub GRUB_CMDLINE_LINUX="page_poison=1" If "page_poison" is not set to "1" or is missing or commented out, this is a finding.

Fix: F-51978r779335_fix

Configure OL 8 to enable page poisoning with the following commands: $ sudo grubby --update-kernel=ALL --args="page_poison=1" Add or modify the following line in "/etc/default/grub" to ensure the configuration survives kernel updates: GRUB_CMDLINE_LINUX="page_poison=1"

b
OL 8 must disable virtual syscalls.
SC-3 - Medium - CCI-001084 - V-248591 - SV-248591r779339_rule
RMF Control
SC-3
Severity
Medium
CCI
CCI-001084
Version
OL08-00-010422
Vuln IDs
  • V-248591
Rule IDs
  • SV-248591r779339_rule
Syscalls are special routines in the Linux kernel, which userspace applications ask to do privileged tasks. Invoking a system call is an expensive operation because the processor must interrupt the currently executing task and switch context to kernel mode and then back to userspace after the system call completes. Virtual syscalls map into user space a page that contains some variables and the implementation of some system calls. This allows the system calls to be executed in userspace to alleviate the context switching expense. Virtual syscalls provide an opportunity of attack for a user who has control of the return instruction pointer. Disabling vsyscalls help to prevent return-oriented programming (ROP) attacks via buffer overflows and overruns. If the system intends to run containers based on OL 6 components, then virtual syscalls will need enabled so the components function properly.
Checks: C-52025r779337_chk

Verify that GRUB 2 is configured to disable vsyscalls with the following commands: $ sudo grub2-editenv list | grep vsyscall kernelopts=root=/dev/mapper/ol-root ro crashkernel=auto resume=/dev/mapper/ol-swap rd.lvm.lv=ol/root rd.lvm.lv=ol/swap rhgb quiet fips=1 page_poison=1 vsyscall=none audit=1 audit_backlog_limit=8192 boot=UUID=8d171156-cd61-421c-ba41-1c021ac29e82 If "vsyscall" is not set to "none" or is missing, this is a finding. Check that vsyscalls are disabled by default to persist in kernel updates: $ sudo grep vsyscall /etc/default/grub GRUB_CMDLINE_LINUX="vsyscall=none" If "vsyscall" is not set to "none", is missing or commented out and is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding.

Fix: F-51979r779338_fix

Document the use of vsyscalls with the ISSO as an operational requirement or disable them with the following command: $ sudo grubby --update-kernel=ALL --args="vsyscall=none" Add or modify the following line in "/etc/default/grub" to ensure the configuration survives kernel updates: GRUB_CMDLINE_LINUX="vsyscall=none"

b
OL 8 must clear SLUB/SLAB objects to prevent use-after-free attacks.
SC-3 - Medium - CCI-001084 - V-248592 - SV-248592r779342_rule
RMF Control
SC-3
Severity
Medium
CCI
CCI-001084
Version
OL08-00-010423
Vuln IDs
  • V-248592
Rule IDs
  • SV-248592r779342_rule
Some adversaries launch attacks with the intent of executing code in non-executable regions of memory or in memory locations that are prohibited. Security safeguards employed to protect memory include, for example, data execution prevention and address space layout randomization. Data execution prevention safeguards can be either hardware-enforced or software-enforced with hardware providing the greater strength of mechanism. Poisoning writes an arbitrary value to freed pages, so any modification or reference to that page after being freed or before being initialized will be detected and prevented. This prevents many types of use-after-free vulnerabilities at little performance cost. Also prevents leak of data and detection of corrupted memory. SLAB objects are blocks of physically-contiguous memory. SLUB is the unqueued SLAB allocator.
Checks: C-52026r779340_chk

Verify that GRUB 2 is configured to enable poisoning of SLUB/SLAB objects to mitigate use-after-free vulnerabilities with the following commands: Check that the current GRUB 2 configuration has poisoning of SLUB/SLAB objects enabled: $ sudo grub2-editenv list | grep slub_debug kernelopts=root=/dev/mapper/ol-root ro crashkernel=auto resume=/dev/mapper/ol-swap rd.lvm.lv=ol/root rd.lvm.lv=ol/swap rhgb quiet fips=1 slub_debug=P page_poison=1 vsyscall=none audit=1 audit_backlog_limit=8192 boot=UUID=8d171156-cd61-421c-ba41-1c021ac29e82 If "slub_debug" is not set to "P" or is missing, this is a finding. Check that poisoning of SLUB/SLAB objects is enabled by default to persist in kernel updates: $ sudo grep slub_debug /etc/default/grub GRUB_CMDLINE_LINUX="slub_debug=P" If "slub_debug" is not set to "P", is missing or commented out, this is a finding.

Fix: F-51980r779341_fix

Configure OL 8 to enable poisoning of SLUB/SLAB objects with the following commands: $ sudo grubby --update-kernel=ALL --args="slub_debug=P" Add or modify the following line in "/etc/default/grub" to ensure the configuration survives kernel updates: GRUB_CMDLINE_LINUX="slub_debug=P"

b
OL 8 must not let Meltdown and Spectre exploit critical vulnerabilities in modern processors.
CM-6 - Medium - CCI-000366 - V-248593 - SV-248593r779345_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010424
Vuln IDs
  • V-248593
Rule IDs
  • SV-248593r779345_rule
Hardware vulnerabilities allow programs to steal data that is currently processed on the computer. While programs are typically not permitted to read data from other programs, a malicious program can exploit Meltdown and Spectre to obtain secrets stored in the memory of other running programs. This might include passwords stored in a password manager or browser; personal photos, emails, and instant messages; and business-critical documents.
Checks: C-52027r779343_chk

Determine the default kernel: $ sudo grubby --default-kernel /boot/vmlinuz-5.4.17-2011.1.2.el8uek.x86_64 Using the default kernel, verify that Meltdown mitigations are not disabled: $ sudo grubby --info=<path-to-default-kernel> | grep mitigation If the mitigation parameter is set to "off" this is a finding.

Fix: F-51981r779344_fix

Determine the default kernel: $ sudo grubby --default-kernel /boot/vmlinuz-5.4.17-2011.1.2.el8uek.x86_64 Using the default kernel, remove the Meltdown mitigations: $ sudo grubby --update-kernel=<path-to-default-kernel> --remove-args=mitigation=off Reboot the system for the change to take effect.

b
OL 8 must implement address space layout randomization (ASLR) to protect its memory from unauthorized code execution.
SI-16 - Medium - CCI-002824 - V-248594 - SV-248594r860918_rule
RMF Control
SI-16
Severity
Medium
CCI
CCI-002824
Version
OL08-00-010430
Vuln IDs
  • V-248594
Rule IDs
  • SV-248594r860918_rule
Some adversaries launch attacks with the intent of executing code in non-executable regions of memory or in memory locations that are prohibited. Security safeguards employed to protect memory include, for example, data execution prevention and address space layout randomization. Data execution prevention safeguards can be either hardware-enforced or software-enforced, with hardware providing the greater strength of mechanism. Examples of attacks are buffer overflow attacks. The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf
Checks: C-52028r858625_chk

Verify that OL 8 implements ASLR with the following command: $ sudo sysctl kernel.randomize_va_space kernel.randomize_va_space = 2 If "kernel.randomize_va_space" is not set to "2", this is a finding. Check that the configuration files are present to enable this kernel parameter. $ sudo grep -r kernel.randomize_va_space /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf:kernel.randomize_va_space = 2 If "kernel.randomize_va_space" is not set to "2", is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-51982r858626_fix

Configure OL 8 to implement virtual address space randomization. Set the system to the required kernel parameter by adding the following line to "/etc/sysctl.d/*.conf" (or modify the line to have the required value): kernel.randomize_va_space=2 Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf Issue the following command to make the changes take effect: $ sudo sysctl --system

a
YUM must remove all software components after updated versions have been installed on OL 8.
SI-2 - Low - CCI-002617 - V-248595 - SV-248595r853773_rule
RMF Control
SI-2
Severity
Low
CCI
CCI-002617
Version
OL08-00-010440
Vuln IDs
  • V-248595
Rule IDs
  • SV-248595r853773_rule
Previous versions of software components that are not removed from the information system after updates have been installed may be exploited by adversaries. Some information technology products may remove older versions of software automatically from the information system.
Checks: C-52029r779349_chk

Verify the operating system removes all software components after updated versions have been installed. Check if YUM is configured to remove unneeded packages with the following command: $ sudo grep -i clean_requirements_on_remove /etc/yum.conf clean_requirements_on_remove=True If "clean_requirements_on_remove" is not set to "True", commented out, or missing from "/etc/yum.conf", this is a finding.

Fix: F-51983r779350_fix

Configure OL 8 to remove all software components after updated versions have been installed. Set the "clean_requirements_on_remove" option to "True" in the "/etc/yum.conf" file: clean_requirements_on_remove=True

b
OL 8 must enable the SELinux targeted policy.
SI-6 - Medium - CCI-002696 - V-248596 - SV-248596r853774_rule
RMF Control
SI-6
Severity
Medium
CCI
CCI-002696
Version
OL08-00-010450
Vuln IDs
  • V-248596
Rule IDs
  • SV-248596r853774_rule
Without verification of the security functions, they may not operate correctly and the failure may go unnoticed. Security function is defined as the hardware, software, and/or firmware of the information system responsible for enforcing the system security policy and supporting the isolation of code and data on which the protection is based. Security functionality includes but is not limited to establishing system accounts, configuring access authorizations (i.e., permissions, privileges), setting events to be audited, and setting intrusion detection parameters. This requirement applies to operating systems performing security function verification/testing and/or systems and environments that require this functionality.
Checks: C-52030r779352_chk

Ensure the operating system verifies correct operation of all security functions. Verify that "SELinux" is active and is enforcing the targeted policy with the following command: $ sudo sestatus SELinux status: enabled SELinuxfs mount: /sys/fs/selinux SELinux root directory: /etc/selinux Loaded policy name: targeted Current mode: enforcing Mode from config file: enforcing Policy MLS status: enabled Policy deny_unknown status: allowed Memory protection checking: actual (secure) Max kernel policy version: 31 If the "Loaded policy name" is not set to "targeted", this is a finding. Verify that the "/etc/selinux/config" file is configured to the "SELINUXTYPE" as "targeted": $ sudo grep -i "selinuxtype" /etc/selinux/config | grep -v '^#' SELINUXTYPE = targeted If no results are returned or "SELINUXTYPE" is not set to "targeted", this is a finding.

Fix: F-51984r779353_fix

Configure OL 8 to verify correct operation of all security functions. Set the "SELinuxtype" to the "targeted" policy by modifying the "/etc/selinux/config" file to have the following line: SELINUXTYPE=targeted A reboot is required for the changes to take effect.

c
There must be no "shosts.equiv" files on the OL 8 operating system.
CM-6 - High - CCI-000366 - V-248597 - SV-248597r779357_rule
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
OL08-00-010460
Vuln IDs
  • V-248597
Rule IDs
  • SV-248597r779357_rule
The "shosts.equiv" files are used to configure host-based authentication for the system via SSH. Host-based authentication is not sufficient for preventing unauthorized access to the system, as it does not require interactive identification and authentication of a connection request, or for the use of two-factor authentication.
Checks: C-52031r779355_chk

Verify there are no "shosts.equiv" files on OL 8 with the following command: $ sudo find / -name shosts.equiv If an "shosts.equiv" file is found, this is a finding.

Fix: F-51985r779356_fix

Remove any found "shosts.equiv" files from the system. $ sudo rm /etc/ssh/shosts.equiv

c
There must be no ".shosts" files on the OL 8 operating system.
CM-6 - High - CCI-000366 - V-248598 - SV-248598r779360_rule
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
OL08-00-010470
Vuln IDs
  • V-248598
Rule IDs
  • SV-248598r779360_rule
The ".shosts" files are used to configure host-based authentication for individual users or the system via SSH. Host-based authentication is not sufficient for preventing unauthorized access to the system, as it does not require interactive identification and authentication of a connection request, or for the use of two-factor authentication.
Checks: C-52032r779358_chk

Verify there are no ".shosts" files on OL 8 with the following command: $ sudo find / -name '*.shosts' If any ".shosts" files are found, this is a finding.

Fix: F-51986r779359_fix

Remove any found ".shosts" files from the system. $ sudo rm /[path]/[to]/[file]/.shosts

a
OL 8 must enable the hardware random number generator entropy gatherer service.
CM-6 - Low - CCI-000366 - V-248599 - SV-248599r943105_rule
RMF Control
CM-6
Severity
Low
CCI
CCI-000366
Version
OL08-00-010473
Vuln IDs
  • V-248599
Rule IDs
  • SV-248599r943105_rule
The most important characteristic of a random number generator is its randomness, namely its ability to deliver random numbers that are impossible to predict. Entropy in computer security is associated with the unpredictability of a source of randomness. The random source with high entropy tends to achieve a uniform distribution of random values. Random number generators are one of the most important building blocks of cryptosystems. The rngd service feeds random data from hardware device to kernel random device. Quality (nonpredictable) random number generation is important for several security functions (i.e., ciphers).
Checks: C-52033r928552_chk

Note: For OL versions 8.4 and above running with kernel FIPS mode enabled as specified by OL08-00-010020, this requirement is Not Applicable. Check that OL 8 has enabled the hardware random number generator entropy gatherer service. Verify the rngd service is enabled and active with the following commands: $ sudo systemctl is-enabled rngd enabled $ sudo systemctl is-active rngd active If the service is not "enabled" and "active", this is a finding.

Fix: F-51987r917909_fix

Start the rngd service and enable it with the following commands: $ sudo systemctl start rngd.service $ sudo systemctl enable rngd.service

a
OL 8 must have the packages required to use the hardware random number generator entropy gatherer service.
CM-6 - Low - CCI-000366 - V-248600 - SV-248600r779366_rule
RMF Control
CM-6
Severity
Low
CCI
CCI-000366
Version
OL08-00-010472
Vuln IDs
  • V-248600
Rule IDs
  • SV-248600r779366_rule
The most important characteristic of a random number generator is its randomness, namely its ability to deliver random numbers that are impossible to predict. Entropy in computer security is associated with the unpredictability of a source of randomness. The random source with high entropy tends to achieve a uniform distribution of random values. Random number generators are one of the most important building blocks of cryptosystems. The rngd service feeds random data from hardware device to kernel random device. Quality (non-predictable) random number generation is important for several security functions (i.e., ciphers).
Checks: C-52034r779364_chk

Check that OL 8 has the packages required to enabled the hardware random number generator entropy gatherer service with the following command: $ sudo yum list installed rng-tools rng-tools.x86_64 6.8-3.el8 @anaconda If the "rng-tools" package is not installed, this is a finding.

Fix: F-51988r779365_fix

Install the packages required to enabled the hardware random number generator entropy gatherer service with the following command: $ sudo yum install rng-tools

b
The OL 8 SSH public host key files must have mode "0644" or less permissive.
CM-6 - Medium - CCI-000366 - V-248601 - SV-248601r779369_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010480
Vuln IDs
  • V-248601
Rule IDs
  • SV-248601r779369_rule
If a public host key file is modified by an unauthorized user, the SSH service may be compromised.
Checks: C-52035r779367_chk

Verify the SSH public host key files have mode "0644" or less permissive with the following command: $ sudo ls -l /etc/ssh/*.pub -rw-r--r-- 1 root wheel 618 Nov 28 06:43 ssh_host_dsa_key.pub -rw-r--r-- 1 root wheel 347 Nov 28 06:43 ssh_host_key.pub -rw-r--r-- 1 root wheel 238 Nov 28 06:43 ssh_host_rsa_key.pub If any "key.pub" file has a mode more permissive than "0644", this is a finding. Note: SSH public key files may be found in other directories on the system depending on the installation.

Fix: F-51989r779368_fix

Change the mode of public host key files under "/etc/ssh" to "0644" with the following command: $ sudo chmod 0644 /etc/ssh/*key.pub The SSH daemon must be restarted for the changes to take effect. To restart the SSH daemon, run the following command: $ sudo systemctl restart sshd.service

b
The OL 8 SSH private host key files must have mode "0640" or less permissive.
CM-6 - Medium - CCI-000366 - V-248602 - SV-248602r880541_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010490
Vuln IDs
  • V-248602
Rule IDs
  • SV-248602r880541_rule
If an unauthorized user obtains the private SSH host key file, the host could be impersonated.
Checks: C-52036r880539_chk

Verify the SSH private host key files have mode "0640" or less permissive with the following command: $ sudo ls -alL /etc/ssh/ssh_host*key -rw-r----- 1 root wheel 668 Nov 28 06:43 ssh_host_dsa_key -rw-r----- 1 root wheel 582 Nov 28 06:43 ssh_host_key -rw-r----- 1 root wheel 887 Nov 28 06:43 ssh_host_rsa_key If any private host key file has a mode more permissive than "0640", this is a finding.

Fix: F-51990r880540_fix

Configure the mode of SSH private host key files under "/etc/ssh" to "0640" with the following command: $ sudo chmod 0640 /etc/ssh/ssh_host*key The SSH daemon must be restarted for the changes to take effect. To restart the SSH daemon, run the following command: $ sudo systemctl restart sshd.service

b
The OL 8 SSH daemon must perform strict mode checking of home directory configuration files.
CM-6 - Medium - CCI-000366 - V-248603 - SV-248603r858568_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010500
Vuln IDs
  • V-248603
Rule IDs
  • SV-248603r858568_rule
If other users have access to modify user-specific SSH configuration files, they may be able to log on to the system as another user.
Checks: C-52037r858567_chk

Verify the SSH daemon performs strict mode checking of home directory configuration files with the following command: $ sudo grep -ir strictmodes /etc/ssh/sshd_config* StrictModes yes If "StrictModes" is set to "no" or is missing, or if the returned line is commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-51991r779374_fix

Configure SSH to perform strict mode checking of home directory configuration files. Uncomment the "StrictModes" keyword in "/etc/ssh/sshd_config" and set the value to "yes": StrictModes yes The SSH daemon must be restarted for the changes to take effect. To restart the SSH daemon, run the following command: $ sudo systemctl restart sshd.service

b
The OL 8 SSH daemon must not allow authentication using known host's authentication.
CM-6 - Medium - CCI-000366 - V-248605 - SV-248605r858572_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010520
Vuln IDs
  • V-248605
Rule IDs
  • SV-248605r858572_rule
Configuring this setting for the SSH daemon provides additional assurance that remote logon via SSH will require a password, even in the event of misconfiguration elsewhere.
Checks: C-52039r858571_chk

Verify the SSH daemon does not allow authentication using known host’s authentication with the following command: $ sudo grep -ir IgnoreUserKnownHosts /etc/ssh/sshd_config* IgnoreUserKnownHosts yes If the value is returned as "no", the returned line is commented out, or no output is returned, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-51993r779380_fix

Configure the SSH daemon to not allow authentication using known host’s authentication. Add the following line in "/etc/ssh/sshd_config", or uncomment the line and set the value to "yes": IgnoreUserKnownHosts yes The SSH daemon must be restarted for the changes to take effect. To restart the SSH daemon, run the following command: $ sudo systemctl restart sshd.service

b
The OL 8 SSH daemon must not allow Kerberos authentication, except to fulfill documented and validated mission requirements.
CM-6 - Medium - CCI-000366 - V-248606 - SV-248606r858574_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010521
Vuln IDs
  • V-248606
Rule IDs
  • SV-248606r858574_rule
Configuring this setting for the SSH daemon provides additional assurance that remote logon via SSH will require a password, even in the event of misconfiguration elsewhere.
Checks: C-52040r858573_chk

Verify the SSH daemon does not allow Kerberos authentication with the following command: $ sudo grep -ir "KerberosAuthentication" /etc/ssh/sshd_config* KerberosAuthentication no If the value is returned as "yes", the returned line is commented out, or no output is returned, or has not been documented with the ISSO, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-51994r779383_fix

Configure the SSH daemon to not allow Kerberos authentication. Add the following line in "/etc/ssh/sshd_config", or uncomment the line and set the value to "no": KerberosAuthentication no The SSH daemon must be restarted for the changes to take effect. To restart the SSH daemon, run the following command: $ sudo systemctl restart sshd.service

b
The OL 8 SSH daemon must not allow GSSAPI authentication, except to fulfill documented and validated mission requirements.
CM-6 - Medium - CCI-000366 - V-248607 - SV-248607r858576_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010522
Vuln IDs
  • V-248607
Rule IDs
  • SV-248607r858576_rule
Configuring this setting for the SSH daemon provides additional assurance that remote logon via SSH will require a password, even in the event of misconfiguration elsewhere.
Checks: C-52041r858575_chk

Verify the SSH daemon does not allow GSSAPI authentication with the following command: $ sudo grep -ir GSSAPIAuthentication /etc/ssh/sshd_config* GSSAPIAuthentication no If the value is returned as "yes", the returned line is commented out, no output is returned, or has not been documented with the ISSO, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-51995r779386_fix

Configure the SSH daemon to not allow GSSAPI authentication. Add the following line in "/etc/ssh/sshd_config", or uncomment the line and set the value to "no": GSSAPIAuthentication no The SSH daemon must be restarted for the changes to take effect. To restart the SSH daemon, run the following command: $ sudo systemctl restart sshd.service

a
OL 8 must use a separate file system for "/var".
CM-6 - Low - CCI-000366 - V-248608 - SV-248608r902793_rule
RMF Control
CM-6
Severity
Low
CCI
CCI-000366
Version
OL08-00-010540
Vuln IDs
  • V-248608
Rule IDs
  • SV-248608r902793_rule
The use of separate file systems for different paths can protect the system from failures resulting from a file system becoming full or failing.
Checks: C-52042r902792_chk

Verify that a separate file system has been created for "/var" with the following command: $ sudo grep /var /etc/fstab /dev/mapper/... /var xfs defaults,nodev 0 0 If a separate entry for "/var" is not in use, this is a finding.

Fix: F-51996r779389_fix

Migrate the "/var" path onto a separate file system.

a
OL 8 must use a separate file system for "/var/log".
CM-6 - Low - CCI-000366 - V-248609 - SV-248609r902795_rule
RMF Control
CM-6
Severity
Low
CCI
CCI-000366
Version
OL08-00-010541
Vuln IDs
  • V-248609
Rule IDs
  • SV-248609r902795_rule
The use of separate file systems for different paths can protect the system from failures resulting from a file system becoming full or failing.
Checks: C-52043r902794_chk

Verify that a separate file system has been created for "/var/log". Check that a file system has been created for "/var/log" with the following command: $ sudo grep /var/log /etc/fstab /dev/mapper/... /var/log xfs defaults,nodev,noexec,nosuid 0 0 If a separate entry for "/var/log" is not in use, this is a finding.

Fix: F-51997r779392_fix

Migrate the "/var/log" path onto a separate file system.

a
OL 8 must use a separate file system for the system audit data path.
CM-6 - Low - CCI-000366 - V-248610 - SV-248610r779396_rule
RMF Control
CM-6
Severity
Low
CCI
CCI-000366
Version
OL08-00-010542
Vuln IDs
  • V-248610
Rule IDs
  • SV-248610r779396_rule
The use of separate file systems for different paths can protect the system from failures resulting from a file system becoming full or failing.
Checks: C-52044r779394_chk

Verify that a separate file system/partition has been created for the system audit data path with the following command: Note: "/var/log/audit" is used as the example as it is a common location. $ sudo grep /var/log/audit /etc/fstab UUID=3645951a /var/log/audit ext4 defaults 1 2 If an entry for "/var/log/audit" does not exist, ask the System Administrator if the system audit logs are being written to a different file system/partition on the system and then grep for that file system/partition. If a separate file system/partition does not exist for the system audit data path, this is a finding.

Fix: F-51998r779395_fix

Migrate the system audit data path onto a separate file system.

b
OL 8 must use a separate file system for "/tmp".
CM-6 - Medium - CCI-000366 - V-248611 - SV-248611r779399_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010543
Vuln IDs
  • V-248611
Rule IDs
  • SV-248611r779399_rule
The use of separate file systems for different paths can protect the system from failures resulting from a file system becoming full or failing.
Checks: C-52045r779397_chk

The use of separate file systems for different paths can protect the system from failures resulting from a file system becoming full or failing. Check Text: Verify that a separate file system/partition has been created for non-privileged local interactive user home directories. $ sudo grep /tmp /etc/fstab /dev/mapper/ol-tmp /tmp xfs defaults,nodev,nosuid,noexec 0 0 If a separate entry for the file system/partition "/tmp" does not exist, this is a finding.

Fix: F-51999r779398_fix

Migrate the "/tmp" directory onto a separate file system/partition.

b
OL 8 must use a separate file system for /var/tmp.
CM-6 - Medium - CCI-000366 - V-248612 - SV-248612r902797_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010544
Vuln IDs
  • V-248612
Rule IDs
  • SV-248612r902797_rule
The use of separate file systems for different paths can protect the system from failures resulting from a file system becoming full or failing.
Checks: C-52046r902796_chk

Verify that a separate file system has been created for "/var/tmp". Check that a file system has been created for "/var/tmp" with the following command: $ sudo grep /var/tmp /etc/fstab /dev/mapper/... /var/tmp xfs defaults,nodev,noexec,nosuid 0 0 If a separate entry for "/var/tmp" is not in use, this is a finding.

Fix: F-52000r779401_fix

Migrate the "/var/tmp" path onto a separate file system.

b
OL 8 must not permit direct logons to the root account using remote access via SSH.
IA-2 - Medium - CCI-000770 - V-248613 - SV-248613r858578_rule
RMF Control
IA-2
Severity
Medium
CCI
CCI-000770
Version
OL08-00-010550
Vuln IDs
  • V-248613
Rule IDs
  • SV-248613r858578_rule
Although the communications channel may be encrypted, an additional layer of security is gained by extending the policy of not logging on directly as root. In addition, logging on with a user-specific account provides individual accountability of actions performed on the system.
Checks: C-52047r858577_chk

Verify remote access using SSH prevents users from logging on directly as "root" with the following command: $ sudo grep -ir PermitRootLogin /etc/ssh/sshd_config* PermitRootLogin no If the "PermitRootLogin" keyword is set to "yes", is missing, or is commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52001r779404_fix

Configure OL 8 to stop users from logging on remotely as the "root" user via SSH. Edit the appropriate "/etc/ssh/sshd_config" file to uncomment or add the line for the "PermitRootLogin" keyword and set its value to "no": PermitRootLogin no The SSH daemon must be restarted for the changes to take effect. To restart the SSH daemon, run the following command: $ sudo systemctl restart sshd.service

b
OL 8 must have the rsyslog service enabled and active.
CM-6 - Medium - CCI-000366 - V-248615 - SV-248615r779411_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010561
Vuln IDs
  • V-248615
Rule IDs
  • SV-248615r779411_rule
Configuring OL 8 to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across the DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example, registry settings; account, file, and directory permission settings; and settings for functions, ports, protocols, services, and remote connections.
Checks: C-52049r779409_chk

Verify the rsyslog service is enabled and active with the following commands: $ sudo systemctl is-enabled rsyslog enabled $ sudo systemctl is-active rsyslog active If the service is not enabled and active, this is a finding.

Fix: F-52003r779410_fix

Start and enable the rsyslog service with the following commands: $ sudo systemctl start rsyslog.service $ sudo systemctl enable rsyslog.service

b
OL 8 must prevent files with the setuid and setgid bit set from being executed on file systems that contain user home directories.
CM-6 - Medium - CCI-000366 - V-248616 - SV-248616r779414_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010570
Vuln IDs
  • V-248616
Rule IDs
  • SV-248616r779414_rule
The "nosuid" mount option causes the system not to execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-52050r779412_chk

Verify that file systems containing user home directories are mounted with the "nosuid" option. Find the file system(s) that contain the user home directories with the following command: $ sudo awk -F: '($3&gt;=1000)&amp;&amp;($1!="nobody"){print $1,$3,$6}' /etc/passwd smithj 1001 /home/smithj robinst 1002 /home/robinst Check the file systems that are mounted at boot time with the following command: $ sudo more /etc/fstab UUID=a411dc99-f2a1-4c87-9e05-184977be8539 /home ext4 rw,relatime,discard,data=ordered,nosuid,nodev,noexec 0 2 If a file system found in "/etc/fstab" refers to the user home directory file system and it does not have the "nosuid" option set, this is a finding.

Fix: F-52004r779413_fix

Configure "/etc/fstab" to use the "nosuid" option on file systems that contain user home directories for interactive users.

b
OL 8 must prevent files with the setuid and setgid bit set from being executed on the /boot directory.
CM-6 - Medium - CCI-000366 - V-248617 - SV-248617r779417_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010571
Vuln IDs
  • V-248617
Rule IDs
  • SV-248617r779417_rule
The "nosuid" mount option causes the system not to execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-52051r779415_chk

For systems that use UEFI, this is Not Applicable. Verify the /boot directory is mounted with the "nosuid" option with the following command: $ sudo mount | grep '\s/boot\s' /dev/sda1 on /boot type xfs (rw,nosuid,relatime,seclabe,attr2,inode64,noquota) If the /boot file system does not have the "nosuid" option set, this is a finding.

Fix: F-52005r779416_fix

Configure the "/etc/fstab" to use the "nosuid" option on the /boot directory.

b
OL 8 must prevent files with the setuid and setgid bit set from being executed on the /boot/efi directory.
CM-6 - Medium - CCI-000366 - V-248618 - SV-248618r818648_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010572
Vuln IDs
  • V-248618
Rule IDs
  • SV-248618r818648_rule
The "nosuid" mount option causes the system not to execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-52052r818647_chk

For systems that use BIOS, this is Not Applicable. Verify the /boot/efi directory is mounted with the "nosuid" option with the following command: $ sudo mount | grep '\s/boot/efi\s' /dev/sda1 on /boot/efi type vfat (rw,nosuid,relatime,fmask=0077,dmask=0077,codepage=437,iocharset=ascii,shortname=winnt,errors=remount-ro) If the /boot/efi file system does not have the "nosuid" option set, this is a finding.

Fix: F-52006r779419_fix

Configure the "/etc/fstab" to use the "nosuid" option on the /boot/efi directory.

b
OL 8 must prevent special devices on non-root local partitions.
CM-6 - Medium - CCI-000366 - V-248619 - SV-248619r779423_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010580
Vuln IDs
  • V-248619
Rule IDs
  • SV-248619r779423_rule
The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The only legitimate location for device files is the /dev directory located on the root partition.
Checks: C-52053r779421_chk

Verify all non-root local partitions are mounted with the "nodev" option with the following command: $ sudo mount | grep '^/dev\S* on /\S' | grep --invert-match 'nodev' If any output is produced, this is a finding.

Fix: F-52007r779422_fix

Configure the "/etc/fstab" to use the "nodev" option on all non-root local partitions.

b
OL 8 file systems that contain user home directories must not execute binary files.
CM-6 - Medium - CCI-000366 - V-248620 - SV-248620r779426_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010590
Vuln IDs
  • V-248620
Rule IDs
  • SV-248620r779426_rule
The "noexec" mount option causes the system not to execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-52054r779424_chk

Verify that file systems containing user home directories are mounted with the "noexec" option. Find the file system(s) that contain the user home directories with the following command: $ sudo awk -F: '($3&gt;=1000)&amp;&amp;($1!="nobody"){print $1,$3,$6}' /etc/passwd smithj 1001 /home/smithj robinst 1002 /home/robinst Check the file systems that are mounted at boot time with the following command: $ sudo more /etc/fstab UUID=a411dc99-f2a1-4c87-9e05-184977be8539 /home ext4 rw,relatime,discard,data=ordered,nosuid,nodev,noexec 0 2 If a file system found in "/etc/fstab" refers to the user home directory file system and it does not have the "noexec" option set, this is a finding.

Fix: F-52008r779425_fix

Configure the "/etc/fstab" to use the "noexec" option on file systems that contain user home directories for interactive users.

b
OL 8 file systems must not interpret character or block special devices from untrusted file systems.
CM-6 - Medium - CCI-000366 - V-248621 - SV-248621r779429_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010600
Vuln IDs
  • V-248621
Rule IDs
  • SV-248621r779429_rule
The "nodev" mount option causes the system not to interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-52055r779427_chk

Verify that file systems used for removable media are mounted with the "nodev" option with the following command: $ sudo more /etc/fstab UUID=2bc871e4-e2a3-4f29-9ece-3be60c835222 /mnt/usbflash vfat noauto,owner,ro,nosuid,nodev,noexec 0 0 If a file system found in "/etc/fstab" refers to removable media and it does not have the "nodev" option set, this is a finding.

Fix: F-52009r779428_fix

Configure the "/etc/fstab" to use the "nodev" option on file systems that are associated with removable media.

b
OL 8 file systems must not execute binary files on removable media.
CM-6 - Medium - CCI-000366 - V-248622 - SV-248622r779432_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010610
Vuln IDs
  • V-248622
Rule IDs
  • SV-248622r779432_rule
The "noexec" mount option causes the system not to execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-52056r779430_chk

Verify that file systems used for removable media are mounted with the "noexec" option with the following command: $ sudo more /etc/fstab UUID=2bc871e4-e2a3-4f29-9ece-3be60c835222 /mnt/usbflash vfat noauto,owner,ro,nosuid,nodev,noexec 0 0 If a file system found in "/etc/fstab" refers to removable media and it does not have the "noexec" option set, this is a finding.

Fix: F-52010r779431_fix

Configure the "/etc/fstab" to use the "noexec" option on file systems that are associated with removable media.

b
OL 8 must prevent files with the setuid and setgid bit set from being executed on file systems that are used with removable media.
CM-6 - Medium - CCI-000366 - V-248623 - SV-248623r779435_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010620
Vuln IDs
  • V-248623
Rule IDs
  • SV-248623r779435_rule
The "nosuid" mount option causes the system not to execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-52057r779433_chk

Verify that file systems used for removable media are mounted with the "nosuid" option with the following command: $ sudo more /etc/fstab UUID=2bc871e4-e2a3-4f29-9ece-3be60c835222 /mnt/usbflash vfat noauto,owner,ro,nosuid,nodev,noexec 0 0 If a file system found in "/etc/fstab" refers to removable media and it does not have the "nosuid" option set, this is a finding.

Fix: F-52011r779434_fix

Configure the "/etc/fstab" to use the "nosuid" option on file systems that are associated with removable media.

b
OL 8 file systems must not execute binary files that are imported via Network File System (NFS).
CM-6 - Medium - CCI-000366 - V-248624 - SV-248624r779438_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010630
Vuln IDs
  • V-248624
Rule IDs
  • SV-248624r779438_rule
The "noexec" mount option causes the system not to execute binary files. This option must be used for mounting any file system not containing approved binary as they may be incompatible. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-52058r779436_chk

Verify that file systems being imported via NFS are mounted with the "noexec" option with the following command: $ sudo grep nfs /etc/fstab | grep noexec UUID=e06097bb-cfcd-437b-9e4d-a691f5662a7d /store nfs rw,nosuid,nodev,noexec 0 0 If a file system found in "/etc/fstab" refers to NFS and it does not have the "noexec" option set, this is a finding.

Fix: F-52012r779437_fix

Configure the "/etc/fstab" to use the "noexec" option on file systems that are being imported via NFS.

b
OL 8 file systems must not interpret character or block special devices that are imported via NFS.
CM-6 - Medium - CCI-000366 - V-248625 - SV-248625r779441_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010640
Vuln IDs
  • V-248625
Rule IDs
  • SV-248625r779441_rule
The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-52059r779439_chk

Verify that file systems being imported via NFS are mounted with the "nodev" option with the following command: $ sudo grep nfs /etc/fstab | grep nodev UUID=e06097bb-cfcd-437b-9e4d-a691f5662a7d /store nfs rw,nosuid,nodev,noexec 0 0 If a file system found in "/etc/fstab" refers to NFS and it does not have the "nodev" option set, this is a finding.

Fix: F-52013r779440_fix

Configure the "/etc/fstab" to use the "nodev" option on file systems that are being imported via NFS.

b
OL 8 must prevent files with the setuid and setgid bit set from being executed on file systems that are imported via Network File System (NFS).
CM-6 - Medium - CCI-000366 - V-248626 - SV-248626r779444_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010650
Vuln IDs
  • V-248626
Rule IDs
  • SV-248626r779444_rule
The "nosuid" mount option causes the system not to execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-52060r779442_chk

Verify that file systems being imported via NFS are mounted with the "nosuid" option with the following command: $ sudo grep nfs /etc/fstab | grep nosuid UUID=e06097bb-cfcd-437b-9e4d-a691f5662a7d /store nfs rw,nosuid,nodev,noexec 0 0 If a file system found in "/etc/fstab" refers to NFS and it does not have the "nosuid" option set, this is a finding.

Fix: F-52014r779443_fix

Configure the "/etc/fstab" to use the "nosuid" option on file systems that are being imported via NFS.

b
Local OL 8 initialization files must not execute world-writable programs.
CM-6 - Medium - CCI-000366 - V-248627 - SV-248627r779447_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010660
Vuln IDs
  • V-248627
Rule IDs
  • SV-248627r779447_rule
If user start-up files execute world-writable programs, especially in unprotected directories, they could be maliciously modified to destroy user files or otherwise compromise the system at the user level. If the system is compromised at the user level, it is easier to elevate privileges to eventually compromise the system at the root and network level.
Checks: C-52061r779445_chk

Verify that local initialization files do not execute world-writable programs. Check the system for world-writable files. The following command will discover and print world-writable files. Run it once for each local partition [PART]: $ sudo find [PART] -xdev -type f -perm -0002 -print For all files listed, check for their presence in the local initialization files with the following commands: Note: The example will be for a system that is configured to create users' home directories in the "/home" directory. $ sudo grep &lt;file&gt; /home/*/.* If any local initialization files are found to reference world-writable files, this is a finding.

Fix: F-52015r779446_fix

Set the mode on files being executed by the local initialization files with the following command: $ sudo chmod 0755 <file>

b
OL 8 must disable kernel dumps unless needed.
SC-24 - Medium - CCI-001665 - V-248628 - SV-248628r779450_rule
RMF Control
SC-24
Severity
Medium
CCI
CCI-001665
Version
OL08-00-010670
Vuln IDs
  • V-248628
Rule IDs
  • SV-248628r779450_rule
Kernel core dumps may contain the full contents of system memory at the time of the crash. Kernel core dumps may consume a considerable amount of disk space and may result in denial of service by exhausting the available space on the target file system partition. OL 8 installation media presents the option to enable or disable the kdump service at the time of system installation.
Checks: C-52062r779448_chk

Verify that kernel core dumps are disabled unless needed with the following command: $ sudo systemctl status kdump.service kdump.service - Crash recovery kernel arming Loaded: loaded (/usr/lib/systemd/system/kdump.service; disabled; vendor preset: enabled) Active: failed (Result: exit-code)since Mon 2020-05-04 16:08:09 EDT; 3min ago Main PID: 1130 (code=exited, status=0/FAILURE) If the "kdump" service is active, ask the System Administrator if the use of the service is required and documented with the Information System Security Officer (ISSO). If the service is active and is not documented, this is a finding.

Fix: F-52016r779449_fix

If kernel core dumps are not required, disable the "kdump" service with the following command: $ sudo systemctl disable kdump.service If kernel core dumps are required, document the need with the ISSO.

b
OL 8 must disable the "kernel.core_pattern".
CM-6 - Medium - CCI-000366 - V-248629 - SV-248629r858629_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010671
Vuln IDs
  • V-248629
Rule IDs
  • SV-248629r858629_rule
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf
Checks: C-52063r833215_chk

Verify that OL 8 disables storing core dumps with the following commands: $ sudo sysctl kernel.core_pattern kernel.core_pattern = |/bin/false If the returned line does not have a value of "|/bin/false", or a line is not returned and the need for core dumps is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding. Check that the configuration files are present to enable this kernel parameter: $ sudo grep -r kernel.core_pattern /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf:kernel.core_pattern = |/bin/false If "kernel.core_pattern" is not set to "|/bin/false", is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52017r858628_fix

Configure OL 8 to disable storing core dumps by adding the following line to a file in the "/etc/sysctl.d" directory: kernel.core_pattern = |/bin/false Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf The system configuration files must be reloaded for the changes to take effect. To reload the contents of the files, run the following command: $ sudo sysctl --system

b
OL 8 must disable acquiring, saving, and processing core dumps.
CM-6 - Medium - CCI-000366 - V-248630 - SV-248630r779456_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010672
Vuln IDs
  • V-248630
Rule IDs
  • SV-248630r779456_rule
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers trying to debug problems. When the kernel invokes "systemd-coredump" to handle a core dump, it runs in privileged mode and will connect to the socket created by the "systemd-coredump.socket" unit. This, in turn, will spawn an unprivileged "systemd-coredump@.service" instance to process the core dump.
Checks: C-52064r779454_chk

Verify OL 8 is not configured to acquire, save, or process core dumps with the following command: $ sudo systemctl status systemd-coredump.socket systemd-coredump.socket Loaded: masked (Reason: Unit systemd-coredump.socket is masked.) Active: inactive (dead) If the "systemd-coredump.socket" is loaded and not masked and the need for core dumps is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding.

Fix: F-52018r779455_fix

Configure the system to disable the "systemd-coredump.socket" with the following commands: $ sudo systemctl disable --now systemd-coredump.socket $ sudo systemctl mask systemd-coredump.socket Created symlink /etc/systemd/system/systemd-coredump.socket -> /dev/null

b
OL 8 must disable core dumps for all users.
CM-6 - Medium - CCI-000366 - V-248631 - SV-248631r779459_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010673
Vuln IDs
  • V-248631
Rule IDs
  • SV-248631r779459_rule
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers trying to debug problems.
Checks: C-52065r779457_chk

Verify the operating system disables core dumps for all users with the following command: $ sudo grep -r -s '^[^#].*core' /etc/security/limits.conf /etc/security/limits.d/*.conf * hard core 0 This can be set as a global domain (with the * wildcard) but may be set differently for multiple domains. If the "core" item is missing or commented out or the value is anything other than "0", and the need for core dumps is not documented with the Information System Security Officer (ISSO) as an operational requirement for all domains that have the "core" item assigned, this is a finding.

Fix: F-52019r779458_fix

Configure OL 8 to disable core dumps for all users. Add the following line to the top of "/etc/security/limits.conf" or in a ".conf" file defined in "/etc/security/limits.d/": * hard core 0

b
OL 8 must disable storing core dumps.
CM-6 - Medium - CCI-000366 - V-248632 - SV-248632r779462_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010674
Vuln IDs
  • V-248632
Rule IDs
  • SV-248632r779462_rule
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers trying to debug problems.
Checks: C-52066r779460_chk

Verify the operating system disables storing core dumps for all users with the following command: $ sudo grep -i storage /etc/systemd/coredump.conf Storage=none If the "Storage" item is missing or commented out or the value is anything other than "none", and the need for core dumps is not documented with the Information System Security Officer (ISSO) as an operational requirement for all domains that have the "core" item assigned, this is a finding.

Fix: F-52020r779461_fix

Configure OL 8 to disable storing core dumps for all users. Add or modify the following line in "/etc/systemd/coredump.conf": Storage=none

b
OL 8 must disable core dump backtraces.
CM-6 - Medium - CCI-000366 - V-248633 - SV-248633r779465_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010675
Vuln IDs
  • V-248633
Rule IDs
  • SV-248633r779465_rule
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers trying to debug problems.
Checks: C-52067r779463_chk

Verify the operating system disables core dump backtraces by issuing the following command: $ sudo grep -i ProcessSizeMax /etc/systemd/coredump.conf ProcessSizeMax=0 If the "ProcessSizeMax" item is missing or commented out or the value is anything other than "0", and the need for core dumps is not documented with the Information System Security Officer (ISSO) as an operational requirement for all domains that have the "core" item assigned, this is a finding.

Fix: F-52021r779464_fix

Configure OL 8 to disable core dump backtraces. Add or modify the following line in "/etc/systemd/coredump.conf": ProcessSizeMax=0

b
For OL 8 systems using Domain Name Servers (DNS) resolution, at least two name servers must be configured.
CM-6 - Medium - CCI-000366 - V-248634 - SV-248634r779468_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010680
Vuln IDs
  • V-248634
Rule IDs
  • SV-248634r779468_rule
To provide availability for name resolution services, multiple redundant name servers are mandated. A failure in name resolution could lead to the failure of security functions requiring name resolution, which may include time synchronization, centralized authentication, and remote system logging.
Checks: C-52068r779466_chk

Determine whether the system is using local or DNS name resolution with the following command: $ sudo grep hosts /etc/nsswitch.conf hosts: files dns If the DNS entry is missing from the host's line in the "/etc/nsswitch.conf" file, the "/etc/resolv.conf" file must be empty. Verify the "/etc/resolv.conf" file is empty with the following command: $ sudo ls -al /etc/resolv.conf -rw-r--r-- 1 root root 0 Aug 19 08:31 resolv.conf If local host authentication is being used and the "/etc/resolv.conf" file is not empty, this is a finding. If the DNS entry is found on the host's line of the "/etc/nsswitch.conf" file, verify the operating system is configured to use two or more name servers for DNS resolution. Determine the name servers used by the system with the following command: $ sudo grep nameserver /etc/resolv.conf nameserver 192.168.1.2 nameserver 192.168.1.3 If fewer than two lines are returned that are not commented out, this is a finding.

Fix: F-52022r779467_fix

Configure OL 8 to use two or more name servers for DNS resolution. By default, "NetworkManager" on OL 8 dynamically updates the "/etc/resolv.conf" file with the DNS settings from active "NetworkManager" connection profiles. However, this feature can be disabled to allow manual configurations. If manually configuring DNS, edit the "/etc/resolv.conf" file to uncomment or add the two or more "nameserver" option lines with the IP address of local authoritative name servers. If local host resolution is being performed, the "/etc/resolv.conf" file must be empty. An empty "/etc/resolv.conf" file can be created as follows: $ sudo echo -n > /etc/resolv.conf

b
Executable search paths within the initialization files of all local interactive OL 8 users must only contain paths that resolve to the system default or the user's home directory.
CM-6 - Medium - CCI-000366 - V-248635 - SV-248635r779471_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010690
Vuln IDs
  • V-248635
Rule IDs
  • SV-248635r779471_rule
The executable search path (typically the PATH environment variable) contains a list of directories for the shell to search to find executables. If this path includes the current working directory (other than the user's home directory), executables in these directories may be executed instead of system commands. This variable is formatted as a colon-separated list of directories. If there is an empty entry, such as a leading or trailing colon or two consecutive colons, this is interpreted as the current working directory. If deviations from the default system search path for the local interactive user are required, they must be documented with the Information System Security Officer (ISSO).
Checks: C-52069r779469_chk

Verify that all local interactive user initialization files' executable search path statements do not contain statements that will reference a working directory other than the users' home directory with the following commands: Note: The example will be for the "smithj" user, which has a home directory of "/home/smithj". $ sudo grep -i path /home/smithj/.* /home/smithj/.bash_profile:PATH=$PATH:$HOME/.local/bin:$HOME/bin /home/smithj/.bash_profile:export PATH If any local interactive user initialization files have executable search path statements that include directories outside of their home directory, this is a finding.

Fix: F-52023r779470_fix

Edit the local interactive user initialization files to change any PATH variable statements that reference directories other than their home directory. If a local interactive user requires path variables to reference a directory owned by the application, it must be documented with the ISSO.

b
All OL 8 world-writable directories must be owned by root, sys, bin, or an application user.
CM-6 - Medium - CCI-000366 - V-248636 - SV-248636r779474_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010700
Vuln IDs
  • V-248636
Rule IDs
  • SV-248636r779474_rule
If a world-writable directory is not owned by root, sys, bin, or an application User Identifier (UID), unauthorized users may be able to modify files created by others. The only authorized public directories are the temporary directories supplied with the system or those designed to be temporary file repositories. The setting is normally reserved for directories used by the system and by users for temporary file storage, (e.g., /tmp), and for directories requiring global read/write access.
Checks: C-52070r779472_chk

The following command will discover and print world-writable directories that are not owned by a system account, given the assumption that only system accounts have a UID lower than 1000. Run it once for each local partition [PART]: $ sudo find [PART] -xdev -type d -perm -0002 -uid +999 -print If there is output, this is a finding.

Fix: F-52024r779473_fix

Investigate any world-writable directories that are not owned by a system account and then delete the files or assign them to an appropriate group.

b
All OL 8 world-writable directories must be group-owned by root, sys, bin, or an application group.
CM-6 - Medium - CCI-000366 - V-248637 - SV-248637r779477_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010710
Vuln IDs
  • V-248637
Rule IDs
  • SV-248637r779477_rule
If a world-writable directory is not group-owned by root, sys, bin, or an application Group Identifier (GID), unauthorized users may be able to modify files created by others. The only authorized public directories are the temporary directories supplied with the system or those designed to be temporary file repositories. The setting is normally reserved for directories used by the system and by users for temporary file storage, (e.g., /tmp), and for directories requiring global read/write access.
Checks: C-52071r779475_chk

The following command will discover and print world-writable directories that are not group-owned by a system account, given the assumption that only system accounts have a gid lower than 1000. Run it once for each local partition [PART]: $ sudo find [PART] -xdev -type d -perm -0002 -gid +999 -print If there is output, this is a finding.

Fix: F-52025r779476_fix

Investigate any world-writable directories that are not group-owned by a system account and then delete the files or assign them to an appropriate group.

b
All OL 8 local interactive users must have a home directory assigned in the "/etc/passwd" file.
CM-6 - Medium - CCI-000366 - V-248638 - SV-248638r779480_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010720
Vuln IDs
  • V-248638
Rule IDs
  • SV-248638r779480_rule
If local interactive users are not assigned a valid home directory, there is no place for the storage and control of files they should own.
Checks: C-52072r779478_chk

Verify local interactive users on OL 8 have a home directory assigned with the following command: $ sudo pwck -r user 'lp': directory '/var/spool/lpd' does not exist user 'news': directory '/var/spool/news' does not exist user 'uucp': directory '/var/spool/uucp' does not exist user 'www-data': directory '/var/www' does not exist Ask the System Administrator (SA) if any users found without home directories are local interactive users. If the SA is unable to provide a response, check for users with a User Identifier (UID) of 1000 or greater with the following command: $ sudo awk -F: '($3&gt;=1000)&amp;&amp;($7 !~ /nologin/){print $1, $3, $6}' /etc/passwd If any interactive users do not have a home directory assigned, this is a finding.

Fix: F-52026r779479_fix

Assign home directories to all local interactive users on OL 8 that currently do not have a home directory assigned.

b
All OL 8 local interactive user home directories must have mode "0750" or less permissive.
CM-6 - Medium - CCI-000366 - V-248639 - SV-248639r779483_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010730
Vuln IDs
  • V-248639
Rule IDs
  • SV-248639r779483_rule
Excessive permissions on local interactive user home directories may allow unauthorized access to user files by other users.
Checks: C-52073r779481_chk

Verify the assigned home directory of all local interactive users has a mode of "0750" or less permissive with the following command. Note: This may miss interactive users that have been assigned a privileged User Identifier (UID). Evidence of interactive use may be obtained from a number of log files containing system logon information. $ sudo ls -ld $(awk -F: '($3&gt;=1000)&amp;&amp;($1!="nobody"){print $6}' /etc/passwd) drwxr-x--- 2 smithj admin 4096 Jun 5 12:41 smithj If home directories of interactive users referenced in "/etc/passwd" do not have a mode of "0750" or less permissive, this is a finding.

Fix: F-52027r779482_fix

Change the mode of interactive users' home directories to "0750" using the following command. Note: The example will be for the user "smithj". $ sudo chmod 0750 /home/smithj

b
All OL 8 local interactive user home directory files must have mode "0750" or less permissive.
CM-6 - Medium - CCI-000366 - V-248640 - SV-248640r779486_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010731
Vuln IDs
  • V-248640
Rule IDs
  • SV-248640r779486_rule
Excessive permissions on local interactive user home directories may allow unauthorized access to user files by other users.
Checks: C-52074r779484_chk

Verify all files and directories contained in a local interactive user home directory, excluding local initialization files, have a mode of "0750". Files that begin with a "." are excluded from this requirement. Note: The example will be for the user "smithj", who has a home directory of "/home/smithj". $ sudo ls -lLR /home/smithj -rwxr-x--- 1 smithj smithj 18 Mar 5 17:06 file1 -rwxr----- 1 smithj smithj 193 Mar 5 17:06 file2 -rw-r-x--- 1 smithj smithj 231 Mar 5 17:06 file3 If any files or directories are found with a mode more permissive than "0750", this is a finding.

Fix: F-52028r779485_fix

Set the mode on files and directories in the local interactive user home directory with the following command: Note: The example will be for the user smithj, who has a home directory of "/home/smithj" and is a member of the users group. $ sudo chmod 0750 /home/smithj/<file or directory>

b
All OL 8 local interactive user home directories must be group-owned by the home directory owner's primary group.
CM-6 - Medium - CCI-000366 - V-248641 - SV-248641r880567_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010740
Vuln IDs
  • V-248641
Rule IDs
  • SV-248641r880567_rule
If the Group Identifier (GID) of a local interactive user’s home directory is not the same as the primary GID of the user, this would allow unauthorized access to the user’s files. Users that share the same group may not be able to access files to which they legitimately should have access.
Checks: C-52075r880565_chk

Verify the assigned home directory of all local interactive users is group-owned by that user’s primary GID with the following command. Note: This may miss local interactive users that have been assigned a privileged User Identifier (UID). Evidence of interactive use may be obtained from a number of log files containing system logon information. The returned directory "/home/smithj" is used as an example. $ sudo ls -ld $(awk -F: '($3&gt;=1000)&amp;&amp;($1!="nobody"){print $6}' /etc/passwd) drwxr-x--- 2 smithj admin 4096 Jun 5 12:41 smithj Check the user's primary group with the following command: $ sudo grep $(grep smithj /etc/passwd | awk -F: '{print $4}') /etc/group admin:x:250:smithj,jonesj,jacksons If the user home directory referenced in "/etc/passwd" is not group-owned by that user’s primary GID, this is a finding.

Fix: F-52029r880566_fix

Change the group owner of a local interactive user’s home directory to the group found in "/etc/passwd" using the following command. Note: The example will be for the user "smithj", who has a home directory of "/home/smithj" and has a primary group of users. $ sudo chgrp users /home/smithj

b
OL 8 must be configured so that all files and directories contained in local interactive user home directories are group-owned by a group of which the home directory owner is a member.
CM-6 - Medium - CCI-000366 - V-248642 - SV-248642r779492_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010741
Vuln IDs
  • V-248642
Rule IDs
  • SV-248642r779492_rule
If a local interactive user's files are group-owned by a group of which the user is not a member, unintended users may be able to access them.
Checks: C-52076r779490_chk

Verify all files and directories in a local interactive user home directory are group-owned by a group that the user is a member. Check the group owner of all files and directories in a local interactive user's home directory with the following command: Note: The example will be for the user "smithj", who has a home directory of "/home/smithj". $ sudo ls -lLR /&lt;home directory&gt;/&lt;users home directory&gt;/ -rw-r--r-- 1 smithj smithj 18 Mar 5 17:06 file1 -rw-r--r-- 1 smithj smithj 193 Mar 5 17:06 file2 -rw-r--r-- 1 smithj sa 231 Mar 5 17:06 file3 If any files found with a group-owner different from the home directory user private group, determine if the user is a member of that group with the following command: $ sudo grep smithj /etc/group sa:x:100:juan,shelley,bob,smithj smithj:x:521:smithj If any files or directories are group owned by a group that the directory owner is not a member of, this is a finding.

Fix: F-52030r779491_fix

Change the group of a local interactive user's files and directories to a group that the interactive user is a member. To change the group owner of a local interactive user's files and directories, use the following command: Note: The example will be for the user smithj, who has a home directory of "/home/smithj" and is a member of the users group. $ sudo chgrp smithj /home/smithj/<file or directory>

b
All OL 8 local interactive user home directories defined in the "/etc/passwd" file must exist.
CM-6 - Medium - CCI-000366 - V-248643 - SV-248643r779495_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010750
Vuln IDs
  • V-248643
Rule IDs
  • SV-248643r779495_rule
If a local interactive user has a home directory defined that does not exist, the user may be given access to the "/" directory as the current working directory upon logon. This could create a denial of service because the user would not be able to access their logon configuration files, and it may give them visibility to system files they normally would not be able to access.
Checks: C-52077r779493_chk

Verify that the assigned home directory of all local interactive users on OL 8 exists with the following command: $ sudo ls -ld $(awk -F: '($3&gt;=1000)&amp;&amp;($1!="nobody"){print $6}' /etc/passwd) drwxr-xr-x 2 smithj admin 4096 Jun 5 12:41 smithj Note: This may miss interactive users that have been assigned a privileged User ID (UID). Evidence of interactive use may be obtained from a number of log files containing system logon information. Check that all referenced home directories exist with the following command: $ sudo pwck -r user 'smithj': directory '/home/smithj' does not exist If any home directories referenced in "/etc/passwd" are returned as not defined, this is a finding.

Fix: F-52031r779494_fix

Create home directories to all local interactive users that currently do not have a home directory assigned. Use the following commands to create the user home directory assigned in "/etc/ passwd". Note: The example will be for the user smithj, who has a home directory of "/home/smithj", a UID of "smithj", and a Group Identifier (GID) of "users assigned" in "/etc/passwd". $ sudo mkdir /home/smithj $ sudo chown smithj /home/smithj $ sudo chgrp users /home/smithj $ sudo chmod 0750 /home/smithj

b
All OL 8 local interactive user accounts must be assigned a home directory upon creation.
CM-6 - Medium - CCI-000366 - V-248644 - SV-248644r779498_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010760
Vuln IDs
  • V-248644
Rule IDs
  • SV-248644r779498_rule
If local interactive users are not assigned a valid home directory, there is no place for the storage and control of files they should own.
Checks: C-52078r779496_chk

Verify all local interactive users on OL 8 are assigned a home directory upon creation with the following command: $ sudo grep -i create_home /etc/login.defs CREATE_HOME yes If the value for "CREATE_HOME" parameter is not set to "yes", the line is missing, or the line is commented out, this is a finding.

Fix: F-52032r779497_fix

Configure OL 8 to assign home directories to all new local interactive users by setting the "CREATE_HOME" parameter in "/etc/login.defs" to "yes" as follows. CREATE_HOME yes

b
All OL 8 local initialization files must have mode "0740" or less permissive.
CM-6 - Medium - CCI-000366 - V-248645 - SV-248645r779501_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010770
Vuln IDs
  • V-248645
Rule IDs
  • SV-248645r779501_rule
Local initialization files are used to configure the user's shell environment upon logon. Malicious modification of these files could compromise accounts upon logon.
Checks: C-52079r779499_chk

Verify that all local initialization files have a mode of "0740" or less permissive with the following command: Note: The example will be for the "smithj" user, who has a home directory of "/home/smithj". $ sudo ls -al /home/smithj/.* | more -rwxr----- 1 smithj users 896 Mar 10 2011 .profile -rwxr----- 1 smithj users 497 Jan 6 2007 .login -rwxr----- 1 smithj users 886 Jan 6 2007 .something If any local initialization files have a mode more permissive than "0740", this is a finding.

Fix: F-52033r779500_fix

Set the mode of the local initialization files to "0740" with the following command: Note: The example will be for the smithj user, who has a home directory of "/home/smithj". $ sudo chmod 0740 /home/smithj/.<INIT_FILE>

b
All OL 8 files and directories must have a valid owner.
CM-6 - Medium - CCI-000366 - V-248646 - SV-248646r779504_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010780
Vuln IDs
  • V-248646
Rule IDs
  • SV-248646r779504_rule
Unowned files and directories may be unintentionally inherited if a user is assigned the same User Identifier "UID" as the UID of the unowned files.
Checks: C-52080r779502_chk

Verify all files and directories on OL 8 have a valid owner with the following command: $ sudo find / -nouser If any files on the system do not have an assigned owner, this is a finding.

Fix: F-52034r779503_fix

Either remove all files and directories from the system that do not have a valid user or assign a valid user to all unowned files and directories on OL 8 with the "chown" command: $ sudo chown <user> <file>

b
All OL 8 files and directories must have a valid group owner.
CM-6 - Medium - CCI-000366 - V-248647 - SV-248647r779507_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010790
Vuln IDs
  • V-248647
Rule IDs
  • SV-248647r779507_rule
Files without a valid group owner may be unintentionally inherited if a group is assigned the same Group Identifier (GID) as the GID of the files without a valid group owner.
Checks: C-52081r779505_chk

Verify all files and directories on OL 8 have a valid group with the following command: $ sudo find / -nogroup If any files on the system do not have an assigned group, this is a finding.

Fix: F-52035r779506_fix

Either remove all files and directories from OL 8 that do not have a valid group, or assign a valid group to all files and directories on the system with the "chgrp" command: $ sudo chgrp <group> <file>

b
A separate OL 8 filesystem must be used for user home directories (such as "/home" or an equivalent).
CM-6 - Medium - CCI-000366 - V-248648 - SV-248648r902800_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010800
Vuln IDs
  • V-248648
Rule IDs
  • SV-248648r902800_rule
The use of separate file systems for different paths can protect the system from failures resulting from a file system becoming full or failing.
Checks: C-52082r902798_chk

Verify that a separate file system has been created for non-privileged local interactive user home directories. Check the home directory assignment for all non-privileged users, users with a User Identifier (UID) greater than 1000, on the system with the following command: $ sudo awk -F: '($3&gt;=1000)&amp;&amp;($1!="nobody"){print $1,$3,$6}' /etc/passwd doej 1001 /home/doej publicj 1002 /home/publicj smithj 1003 /home/smithj The output of the command will give the directory that contains the home directories for the nonprivileged users on the system (in this example, "/home") and users’ shell. All accounts with a valid shell (such as "/bin/bash") are considered interactive users. Check that a file system has been created for the nonprivileged interactive users with the following command. Note: The partition of "/home" is used in the example. $ sudo grep /home /etc/fstab /dev/mapper/... /home xfs defaults,noexec,nosuid,nodev 0 0 If a separate entry for the file system that contains the nonprivileged interactive users' home directories does not exist, this is a finding.

Fix: F-52036r902799_fix

Migrate the "/home" directory onto a separate file system.

c
Unattended or automatic logon via the OL 8 graphical user interface must not be allowed.
CM-6 - High - CCI-000366 - V-248649 - SV-248649r877377_rule
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
OL08-00-010820
Vuln IDs
  • V-248649
Rule IDs
  • SV-248649r877377_rule
Failure to restrict system access to authenticated users negatively impacts operating system security.
Checks: C-52083r779511_chk

Note: This requirement assumes the use of the OL 8 default graphical user interface, Gnome Shell. If the system does not have any graphical user interface installed, this requirement is Not Applicable. Verify the operating system does not allow an unattended or automatic logon to the system via a graphical user interface. Check for the value of "AutomaticLoginEnable" in the "/etc/gdm/custom.conf" file with the following command: $ sudo grep -i automaticloginenable /etc/gdm/custom.conf AutomaticLoginEnable=false If the value of "AutomaticLoginEnable" is not set to "false", this is a finding.

Fix: F-52037r779512_fix

Configure OL 8 to not allow an unattended or automatic logon to the system via a graphical user interface. Add or edit the line for the "AutomaticLoginEnable" parameter in the [daemon] section of the "/etc/gdm/custom.conf" file to "false": [daemon] AutomaticLoginEnable=false

c
OL 8 must not allow users to override SSH environment variables.
CM-6 - High - CCI-000366 - V-248650 - SV-248650r877377_rule
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
OL08-00-010830
Vuln IDs
  • V-248650
Rule IDs
  • SV-248650r877377_rule
SSH environment options potentially allow users to bypass access restriction in some configurations.
Checks: C-52084r858579_chk

Verify that unattended or automatic login via SSH is disabled with the following command: $ sudo grep -ir PermitUserEnvironment /etc/ssh/sshd_config* PermitUserEnvironment no If "PermitUserEnvironment" is set to "yes", is missing completely, or is commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52038r779515_fix

Configure OL 8 to allow the SSH daemon to not allow unattended or automatic login to the system. Add or edit the following line in the "/etc/ssh/sshd_config" file: PermitUserEnvironment no The SSH daemon must be restarted for the changes to take effect. To restart the SSH daemon, run the following command: $ sudo systemctl restart sshd.service

b
OL 8 temporary user accounts must be provisioned with an expiration time of 72 hours or less.
AC-2 - Medium - CCI-000016 - V-248651 - SV-248651r779519_rule
RMF Control
AC-2
Severity
Medium
CCI
CCI-000016
Version
OL08-00-020000
Vuln IDs
  • V-248651
Rule IDs
  • SV-248651r779519_rule
If temporary user accounts remain active when no longer needed or for an excessive period, these accounts may be used to gain unauthorized access. To mitigate this risk, automated termination of all temporary accounts must be set upon account creation. Temporary accounts are established as part of normal account activation procedures when there is a need for short-term accounts without the demand for immediacy in account activation. If temporary accounts are used, OL 8 must be configured to automatically terminate these types of accounts after a DoD-defined time period of 72 hours. To address access requirements, many OL 8 operating systems may be integrated with enterprise-level authentication/access mechanisms that meet or exceed access control policy requirements.
Checks: C-52085r779517_chk

Verify that temporary accounts have been provisioned with an expiration date of 72 hours. For every existing temporary account, run the following command to obtain its account expiration information. $ sudo chage -l system_account_name Verify each of these accounts has an expiration date set within 72 hours. If any temporary accounts have no expiration date set or do not expire within 72 hours, this is a finding.

Fix: F-52039r779518_fix

If a temporary account must be created, configure the system to terminate the account after a 72-hour time period with the following command to set an expiration date on it. Substitute "system_account_name" with the account to be created. $ sudo chage -E `date -d "+3 days" +%Y-%m-%d` system_account_name

b
OL 8 systems below version 8.2 must automatically lock an account when three unsuccessful logon attempts occur.
AC-7 - Medium - CCI-000044 - V-248652 - SV-248652r853775_rule
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020010
Vuln IDs
  • V-248652
Rule IDs
  • SV-248652r853775_rule
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. OL 8 can use the "pam_faillock.so" for this purpose. Note that manual changes to the listed files may be overwritten by the "authselect" program. From "Pam_Faillock" man pages: Note that the default directory that "pam_faillock" uses is usually cleared on system boot so the access will be reenabled after system reboot. If that is undesirable, a different tally directory must be set with the "dir" option. Satisfies: SRG-OS-000021-GPOS-00005, SRG-OS-000329-GPOS-00128
Checks: C-52086r779520_chk

Verify the system locks an account after three unsuccessful logon attempts with the following commands. Note: If the System Administrator demonstrates the use of an approved centralized account management method that locks an account after three unsuccessful logon attempts within a period of 15 minutes, this requirement is not applicable. Note: This check applies to OL versions 8.0 and 8.1. If the system is OL version 8.2 or newer, this check is not applicable. $ sudo grep pam_faillock.so /etc/pam.d/password-auth auth required pam_faillock.so preauth dir=/var/log/faillock silent audit deny=3 even_deny_root fail_interval=900 unlock_time=0 auth required pam_faillock.so authfail dir=/var/log/faillock unlock_time=0 account required pam_faillock.so If the "deny" option is not set to "3" or less (but not "0") on the "preauth" line with the "pam_faillock.so" module or is missing from this line, this is a finding. If any line referencing the "pam_faillock.so" module is commented out, this is a finding. $ sudo grep pam_faillock.so /etc/pam.d/system-auth auth required pam_faillock.so preauth dir=/var/log/faillock silent audit deny=3 even_deny_root fail_interval=900 unlock_time=0 auth required pam_faillock.so authfail dir=/var/log/faillock unlock_time=0 account required pam_faillock.so If the "deny" option is not set to "3" or less (but not "0") on the "preauth" line with the "pam_faillock.so" module or is missing from this line, this is a finding. If any line referencing the "pam_faillock.so" module is commented out, this is a finding.

Fix: F-52040r779521_fix

Add/modify the appropriate sections of the "/etc/pam.d/system-auth" and "/etc/pam.d/password-auth" files to match the following lines: auth required pam_faillock.so preauth dir=/var/log/faillock silent audit deny=3 even_deny_root fail_interval=900 unlock_time=0 auth required pam_faillock.so authfail dir=/var/log/faillock unlock_time=0 account required pam_faillock.so The "sssd" service must be restarted for the changes to take effect. To restart the "sssd" service, run the following command: $ sudo systemctl restart sssd.service

b
OL 8 systems, versions 8.2 and above, must automatically lock an account when three unsuccessful logon attempts occur.
AC-7 - Medium - CCI-000044 - V-248653 - SV-248653r853776_rule
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020011
Vuln IDs
  • V-248653
Rule IDs
  • SV-248653r853776_rule
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. In OL 8.2, the "/etc/security/faillock.conf" file was incorporated to centralize the configuration of the "pam_faillock.so" module. Also introduced is a "local_users_only" option that will only track failed user authentication attempts for local users in "/etc/passwd" and ignore centralized (AD, IdM, LDAP, etc.) users to allow the centralized platform to solely manage user lockout. From "faillock.conf" man pages: Note that the default directory that "pam_faillock" uses is usually cleared on system boot so the access will be reenabled after system reboot. If that is undesirable, a different tally directory must be set with the "dir" option. Satisfies: SRG-OS-000021-GPOS-00005, SRG-OS-000329-GPOS-00128
Checks: C-52087r779523_chk

Note: This check applies to OL versions 8.2 or newer. If the system is OL version 8.0 or 8.1, this check is not applicable. Verify the "/etc/security/faillock.conf" file is configured to lock an account after three unsuccessful logon attempts: $ sudo grep 'deny =' /etc/security/faillock.conf deny = 3 If the "deny" option is not set to "3" or less (but not "0") or is missing or commented out, this is a finding.

Fix: F-52041r779524_fix

Configure OL 8 to lock an account when three unsuccessful logon attempts occur. Add/modify the "/etc/security/faillock.conf" file to match the following line: deny = 3

b
OL 8 systems below version 8.2 must automatically lock an account when three unsuccessful logon attempts occur during a 15-minute time period.
AC-7 - Medium - CCI-000044 - V-248654 - SV-248654r853777_rule
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020012
Vuln IDs
  • V-248654
Rule IDs
  • SV-248654r853777_rule
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. OL 8 can use the "pam_faillock.so" for this purpose. Note that manual changes to the listed files may be overwritten by the "authselect" program. From "Pam_Faillock" man pages: Note that the default directory that "pam_faillock" uses is usually cleared on system boot so the access will be reenabled after system reboot. If that is undesirable, a different tally directory must be set with the "dir" option. Satisfies: SRG-OS-000021-GPOS-00005, SRG-OS-000329-GPOS-00128
Checks: C-52088r779526_chk

Verify the system locks an account after three unsuccessful logon attempts within a period of 15 minutes with the following commands. Note: If the System Administrator demonstrates the use of an approved centralized account management method that locks an account after three unsuccessful logon attempts within a period of 15 minutes, this requirement is not applicable. Note: This check applies to OL versions 8.0 and 8.1. If the system is OL version 8.2 or newer, this check is not applicable. $ sudo grep pam_faillock.so /etc/pam.d/password-auth auth required pam_faillock.so preauth dir=/var/log/faillock silent audit deny=3 even_deny_root fail_interval=900 unlock_time=0 auth required pam_faillock.so authfail dir=/var/log/faillock unlock_time=0 account required pam_faillock.so If the "fail_interval" option is not set to "900" or more on the "preauth" lines with the "pam_faillock.so" module or is missing from this line, this is a finding. $ sudo grep pam_faillock.so /etc/pam.d/system-auth auth required pam_faillock.so preauth dir=/var/log/faillock silent audit deny=3 even_deny_root fail_interval=900 unlock_time=0 auth required pam_faillock.so authfail dir=/var/log/faillock unlock_time=0 account required pam_faillock.so If the "fail_interval" option is not set to "900" or more on the "preauth" lines with the "pam_faillock.so" module or is missing from this line, this is a finding.

Fix: F-52042r779527_fix

Configure the operating system to lock an account when three unsuccessful logon attempts occur in 15 minutes. Add/modify the appropriate sections of the "/etc/pam.d/system-auth" and "/etc/pam.d/password-auth" files to match the following lines: auth required pam_faillock.so preauth dir=/var/log/faillock silent audit deny=3 even_deny_root fail_interval=900 unlock_time=0 auth required pam_faillock.so authfail dir=/var/log/faillock unlock_time=0 account required pam_faillock.so The "sssd" service must be restarted for the changes to take effect. To restart the "sssd" service, run the following command: $ sudo systemctl restart sssd.service

b
OL 8 systems, versions 8.2 and above, must automatically lock an account when three unsuccessful logon attempts occur during a 15-minute time period.
AC-7 - Medium - CCI-000044 - V-248655 - SV-248655r853778_rule
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020013
Vuln IDs
  • V-248655
Rule IDs
  • SV-248655r853778_rule
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. In OL 8.2, the "/etc/security/faillock.conf" file was incorporated to centralize the configuration of the "pam_faillock.so" module. Also introduced is a "local_users_only" option that will only track failed user authentication attempts for local users in "/etc/passwd" and ignore centralized (AD, IdM, LDAP, etc.) users to allow the centralized platform to solely manage user lockout. From "faillock.conf" man pages: Note that the default directory that "pam_faillock" uses is usually cleared on system boot so the access will be reenabled after system reboot. If that is undesirable, a different tally directory must be set with the "dir" option. Satisfies: SRG-OS-000021-GPOS-00005, SRG-OS-000329-GPOS-00128
Checks: C-52089r779529_chk

Note: This check applies to OL versions 8.2 or newer. If the system is OL version 8.0 or 8.1, this check is not applicable. Verify the "/etc/security/faillock.conf" file is configured to lock an account after three unsuccessful logon attempts within 15 minutes: $ sudo grep 'fail_interval =' /etc/security/faillock.conf fail_interval = 900 If the "fail_interval" option is not set to "900" or more or is missing or commented out, this is a finding.

Fix: F-52043r779530_fix

Configure OL 8 to lock an account when three unsuccessful logon attempts occur. Add/modify the "/etc/security/faillock.conf" file to match the following line: fail_interval = 900

b
OL 8 systems below version 8.2 must automatically lock an account until the locked account is released by an administrator when three unsuccessful logon attempts occur during a 15-minute time period.
AC-7 - Medium - CCI-000044 - V-248656 - SV-248656r853779_rule
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020014
Vuln IDs
  • V-248656
Rule IDs
  • SV-248656r853779_rule
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. OL 8 can use the "pam_faillock.so" for this purpose. Note that manual changes to the listed files may be overwritten by the "authselect" program. From "Pam_Faillock" man pages: Note that the default directory that "pam_faillock" uses is usually cleared on system boot so the access will be reenabled after system reboot. If that is undesirable, a different tally directory must be set with the "dir" option. Satisfies: SRG-OS-000021-GPOS-00005, SRG-OS-000329-GPOS-00128
Checks: C-52090r779532_chk

Verify the system locks an account after three unsuccessful logon attempts within a period of 15 minutes until released by an administrator with the following commands. Note: If the System Administrator demonstrates the use of an approved centralized account management method that locks an account after three unsuccessful logon attempts within a period of 15 minutes, this requirement is not applicable. Note: This check applies to OL versions 8.0 and 8.1. If the system is OL version 8.2 or newer, this check is not applicable. $ sudo grep pam_faillock.so /etc/pam.d/password-auth auth required pam_faillock.so preauth dir=/var/log/faillock silent audit deny=3 even_deny_root fail_interval=900 unlock_time=0 auth required pam_faillock.so authfail dir=/var/log/faillock unlock_time=0 account required pam_faillock.so If the "unlock_time" option is not set to "0" on the "preauth" and "authfail" lines with the "pam_faillock.so" module or is missing from these lines, this is a finding. $ sudo grep pam_faillock.so /etc/pam.d/system-auth auth required pam_faillock.so preauth dir=/var/log/faillock silent audit deny=3 even_deny_root fail_interval=900 unlock_time=0 auth required pam_faillock.so authfail dir=/var/log/faillock unlock_time=0 account required pam_faillock.so If the "unlock_time" option is not set to "0" on the "preauth" and "authfail" lines with the "pam_faillock.so" module or is missing from these lines, this is a finding.

Fix: F-52044r779533_fix

Configure the operating system to lock an account until released by an administrator when three unsuccessful logon attempts occur in 15 minutes. Add/modify the appropriate sections of the "/etc/pam.d/system-auth" and "/etc/pam.d/password-auth" files to match the following lines: auth required pam_faillock.so preauth dir=/var/log/faillock silent audit deny=3 even_deny_root fail_interval=900 unlock_time=0 auth required pam_faillock.so authfail dir=/var/log/faillock unlock_time=0 account required pam_faillock.so The "sssd" service must be restarted for the changes to take effect. To restart the "sssd" service, run the following command: $ sudo systemctl restart sssd.service

b
OL 8 systems, versions 8.2 and above, must automatically lock an account until the locked account is released by an administrator when three unsuccessful logon attempts occur during a 15-minute time period.
AC-7 - Medium - CCI-000044 - V-248657 - SV-248657r853780_rule
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020015
Vuln IDs
  • V-248657
Rule IDs
  • SV-248657r853780_rule
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. In OL 8.2, the "/etc/security/faillock.conf" file was incorporated to centralize the configuration of the "pam_faillock.so" module. Also introduced is a "local_users_only" option that will only track failed user authentication attempts for local users in "/etc/passwd" and ignore centralized (AD, IdM, LDAP, etc.) users to allow the centralized platform to solely manage user lockout. From "faillock.conf" man pages: Note that the default directory that "pam_faillock" uses is usually cleared on system boot so the access will be reenabled after system reboot. If that is undesirable, a different tally directory must be set with the "dir" option. Satisfies: SRG-OS-000021-GPOS-00005, SRG-OS-000329-GPOS-00128
Checks: C-52091r779535_chk

Note: This check applies to OL versions 8.2 or newer. If the system is OL version 8.0 or 8.1, this check is not applicable. Verify the "/etc/security/faillock.conf" file is configured to lock an account until released by an administrator after three unsuccessful logon attempts: $ sudo grep 'unlock_time =' /etc/security/faillock.conf unlock_time = 0 If the "unlock_time" option is not set to "0" or is missing or commented out, this is a finding.

Fix: F-52045r779536_fix

Configure OL 8 to lock an account until released by an administrator when three unsuccessful logon attempts occur in 15 minutes. Add/modify the "/etc/security/faillock.conf" file to match the following line: unlock_time = 0

b
OL 8 systems below version 8.2 must ensure account lockouts persist.
AC-7 - Medium - CCI-000044 - V-248658 - SV-248658r853781_rule
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020016
Vuln IDs
  • V-248658
Rule IDs
  • SV-248658r853781_rule
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. OL 8 can use the "pam_faillock.so" for this purpose. Note that manual changes to the listed files may be overwritten by the "authselect" program. From "Pam_Faillock" man pages: Note that the default directory that "pam_faillock" uses is usually cleared on system boot so the access will be reenabled after system reboot. If that is undesirable, a different tally directory must be set with the "dir" option. Satisfies: SRG-OS-000021-GPOS-00005, SRG-OS-000329-GPOS-00128
Checks: C-52092r779538_chk

Verify the faillock directory contents persist after a reboot with the following commands: Note: If the System Administrator demonstrates the use of an approved centralized account management method that locks an account after three unsuccessful logon attempts within a period of 15 minutes, this requirement is not applicable. Note: This check applies to OL versions 8.0 and 8.1. If the system is OL version 8.2 or newer, this check is not applicable. $ sudo grep pam_faillock.so /etc/pam.d/password-auth auth required pam_faillock.so preauth dir=/var/log/faillock silent audit deny=3 even_deny_root fail_interval=900 unlock_time=0 auth required pam_faillock.so authfail dir=/var/log/faillock unlock_time=0 account required pam_faillock.so If the "dir" option is not set to a non-default documented tally log directory on the "preauth" and "authfail" lines with the "pam_faillock.so" module or is missing from these lines, this is a finding. $ sudo grep pam_faillock.so /etc/pam.d/system-auth auth required pam_faillock.so preauth dir=/var/log/faillock silent audit deny=3 even_deny_root fail_interval=900 unlock_time=0 auth required pam_faillock.so authfail dir=/var/log/faillock unlock_time=0 account required pam_faillock.so If the "dir" option is not set to a non-default documented tally log directory on the "preauth" and "authfail" lines with the "pam_faillock.so" module or is missing from these lines, this is a finding.

Fix: F-52046r779539_fix

Configure the operating system maintain the contents of the faillock directory after a reboot. Add/modify the appropriate sections of the "/etc/pam.d/system-auth" and "/etc/pam.d/password-auth" files to match the following lines. Note: Using the default faillock directory of "/var/run/faillock" will result in the contents being cleared in the event of a reboot. auth required pam_faillock.so preauth dir=/var/log/faillock silent audit deny=3 even_deny_root fail_interval=900 unlock_time=0 auth required pam_faillock.so authfail dir=/var/log/faillock unlock_time=0 account required pam_faillock.so The "sssd" service must be restarted for the changes to take effect. To restart the "sssd" service, run the following command: $ sudo systemctl restart sssd.service

b
OL 8 systems, versions 8.2 and above, must ensure account lockouts persist.
AC-7 - Medium - CCI-000044 - V-248659 - SV-248659r853782_rule
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020017
Vuln IDs
  • V-248659
Rule IDs
  • SV-248659r853782_rule
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. In OL 8.2, the "/etc/security/faillock.conf" file was incorporated to centralize the configuration of the "pam_faillock.so" module. Also introduced is a "local_users_only" option that will only track failed user authentication attempts for local users in "/etc/passwd" and ignore centralized (AD, IdM, LDAP, etc.) users to allow the centralized platform to solely manage user lockout. From "faillock.conf" man pages: Note that the default directory that "pam_faillock" uses is usually cleared on system boot so the access will be reenabled after system reboot. If that is undesirable, a different tally directory must be set with the "dir" option. Satisfies: SRG-OS-000021-GPOS-00005, SRG-OS-000329-GPOS-00128
Checks: C-52093r779541_chk

Note: This check applies to OL versions 8.2 or newer. If the system is OL version 8.0 or 8.1, this check is not applicable. Verify the "/etc/security/faillock.conf" file is configured use a non-default faillock directory to ensure contents persist after reboot: $ sudo grep 'dir =' /etc/security/faillock.conf dir = /var/log/faillock If the "dir" option is not set to a non-default documented tally log directory or is missing or commented out, this is a finding.

Fix: F-52047r779542_fix

Configure OL 8 to maintain the contents of the faillock directory after a reboot. Add/modify the "/etc/security/faillock.conf" file to match the following line: dir = /var/log/faillock

b
OL 8 systems below version 8.2 must prevent system messages from being presented when three unsuccessful logon attempts occur.
AC-7 - Medium - CCI-000044 - V-248660 - SV-248660r853783_rule
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020018
Vuln IDs
  • V-248660
Rule IDs
  • SV-248660r853783_rule
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. OL 8 can use the "pam_faillock.so" for this purpose. Note that manual changes to the listed files may be overwritten by the "authselect" program. From "Pam_Faillock" man pages: Note that the default directory that "pam_faillock" uses is usually cleared on system boot so the access will be reenabled after system reboot. If that is undesirable, a different tally directory must be set with the "dir" option. Satisfies: SRG-OS-000021-GPOS-00005, SRG-OS-000329-GPOS-00128
Checks: C-52094r779544_chk

Verify the system prevents informative messages from being presented to the user pertaining to logon information with the following commands. Note: If the System Administrator demonstrates the use of an approved centralized account management method that locks an account after three unsuccessful logon attempts within a period of 15 minutes, this requirement is not applicable. Note: This check applies to OL versions 8.0 and 8.1. If the system is OL version 8.2 or newer, this check is not applicable. $ sudo grep pam_faillock.so /etc/pam.d/password-auth auth required pam_faillock.so preauth dir=/var/log/faillock silent audit deny=3 even_deny_root fail_interval=900 unlock_time=0 auth required pam_faillock.so authfail dir=/var/log/faillock unlock_time=0 account required pam_faillock.so If the "silent" option is missing from the "preauth" line with the "pam_faillock.so" module, this is a finding. $ sudo grep pam_faillock.so /etc/pam.d/system-auth auth required pam_faillock.so preauth dir=/var/log/faillock silent audit deny=3 even_deny_root fail_interval=900 unlock_time=0 auth required pam_faillock.so authfail dir=/var/log/faillock unlock_time=0 account required pam_faillock.so If the "silent" option is missing from the "preauth" line with the "pam_faillock.so" module, this is a finding.

Fix: F-52048r779545_fix

Configure the operating system to prevent informative messages from being presented at logon attempts. Add/modify the appropriate sections of the "/etc/pam.d/system-auth" and "/etc/pam.d/password-auth" files to match the following lines: auth required pam_faillock.so preauth dir=/var/log/faillock silent audit deny=3 even_deny_root fail_interval=900 unlock_time=0 auth required pam_faillock.so authfail dir=/var/log/faillock unlock_time=0 account required pam_faillock.so The "sssd" service must be restarted for the changes to take effect. To restart the "sssd" service, run the following command: $ sudo systemctl restart sssd.service

b
OL 8 systems, versions 8.2 and above, must prevent system messages from being presented when three unsuccessful logon attempts occur.
AC-7 - Medium - CCI-000044 - V-248661 - SV-248661r853784_rule
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020019
Vuln IDs
  • V-248661
Rule IDs
  • SV-248661r853784_rule
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. In OL 8.2, the "/etc/security/faillock.conf" file was incorporated to centralize the configuration of the" pam_faillock.so" module. Also introduced is a "local_users_only" option that will only track failed user authentication attempts for local users in "/etc/passwd" and ignore centralized (AD, IdM, LDAP, etc.) users to allow the centralized platform to solely manage user lockout. From "faillock.conf" man pages: Note that the default directory that "pam_faillock" uses is usually cleared on system boot so the access will be reenabled after system reboot. If that is undesirable, a different tally directory must be set with the "dir" option. Satisfies: SRG-OS-000021-GPOS-00005, SRG-OS-000329-GPOS-00128
Checks: C-52095r779547_chk

Note: This check applies to OL versions 8.2 or newer. If the system is OL version 8.0 or 8.1, this check is not applicable. Verify the "/etc/security/faillock.conf" file is configured to prevent informative messages from being presented at logon attempts: $ sudo grep silent /etc/security/faillock.conf silent If the "silent" option is not set or is missing or commented out, this is a finding.

Fix: F-52049r779548_fix

Configure the operating system to prevent informative messages from being presented at logon attempts. Add/modify the "/etc/security/faillock.conf" file to match the following line: silent

b
OL 8 systems below version 8.2 must log user name information when unsuccessful logon attempts occur.
AC-7 - Medium - CCI-000044 - V-248662 - SV-248662r853785_rule
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020020
Vuln IDs
  • V-248662
Rule IDs
  • SV-248662r853785_rule
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. OL 8 can use the "pam_faillock.so" for this purpose. Note that manual changes to the listed files may be overwritten by the "authselect" program. From "Pam_Faillock" man pages: Note that the default directory that "pam_faillock" uses is usually cleared on system boot so the access will be reenabled after system reboot. If that is undesirable, a different tally directory must be set with the "dir" option. Satisfies: SRG-OS-000021-GPOS-00005, SRG-OS-000329-GPOS-00128
Checks: C-52096r779550_chk

Verify the system logs user name information when unsuccessful logon attempts occur with the following commands. Note: If the System Administrator demonstrates the use of an approved centralized account management method that locks an account after three unsuccessful logon attempts within a period of 15 minutes, this requirement is not applicable. Note: This check applies to OL versions 8.0 and 8.1. If the system is OL version 8.2 or newer, this check is not applicable. $ sudo grep pam_faillock.so /etc/pam.d/password-auth auth required pam_faillock.so preauth dir=/var/log/faillock silent audit deny=3 even_deny_root fail_interval=900 unlock_time=0 auth required pam_faillock.so authfail dir=/var/log/faillock unlock_time=0 account required pam_faillock.so If the "audit" option is missing from the "preauth" line with the "pam_faillock.so" module, this is a finding. $ sudo grep pam_faillock.so /etc/pam.d/system-auth auth required pam_faillock.so preauth dir=/var/log/faillock silent audit deny=3 even_deny_root fail_interval=900 unlock_time=0 auth required pam_faillock.so authfail dir=/var/log/faillock unlock_time=0 account required pam_faillock.so If the "audit" option is missing from the "preauth" line with the "pam_faillock.so" module, this is a finding.

Fix: F-52050r779551_fix

Configure the operating system to log user name information when unsuccessful logon attempts occur. Add/modify the appropriate sections of the "/etc/pam.d/system-auth" and "/etc/pam.d/password-auth" files to match the following lines: auth required pam_faillock.so preauth dir=/var/log/faillock silent audit deny=3 even_deny_root fail_interval=900 unlock_time=0 auth required pam_faillock.so authfail dir=/var/log/faillock unlock_time=0 account required pam_faillock.so The "sssd" service must be restarted for the changes to take effect. To restart the "sssd" service, run the following command: $ sudo systemctl restart sssd.service

b
OL 8 systems, versions 8.2 and above, must log user name information when unsuccessful logon attempts occur.
AC-7 - Medium - CCI-000044 - V-248663 - SV-248663r853786_rule
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020021
Vuln IDs
  • V-248663
Rule IDs
  • SV-248663r853786_rule
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. In OL 8.2, the "/etc/security/faillock.conf" file was incorporated to centralize the configuration of the "pam_faillock.so" module. Also introduced is a "local_users_only" option that will only track failed user authentication attempts for local users in "/etc/passwd" and ignore centralized (AD, IdM, LDAP, etc.) users to allow the centralized platform to solely manage user lockout. From "faillock.conf" man pages: Note that the default directory that "pam_faillock" uses is usually cleared on system boot so the access will be reenabled after system reboot. If that is undesirable, a different tally directory must be set with the "dir" option. Satisfies: SRG-OS-000021-GPOS-00005, SRG-OS-000329-GPOS-00128
Checks: C-52097r779553_chk

Note: This check applies to OL versions 8.2 or newer. If the system is OL version 8.0 or 8.1, this check is not applicable. Verify the "/etc/security/faillock.conf" file is configured to log user name information when unsuccessful logon attempts occur: $ sudo grep audit /etc/security/faillock.conf audit If the "audit" option is not set, is missing or commented out, this is a finding.

Fix: F-52051r779554_fix

Configure the operating system to log user name information when unsuccessful logon attempts occur. Add/modify the "/etc/security/faillock.conf" file to match the following line: audit

b
OL 8 systems below version 8.2 must include root when automatically locking an account until the locked account is released by an administrator when three unsuccessful logon attempts occur during a 15-minute time period.
AC-7 - Medium - CCI-000044 - V-248664 - SV-248664r853787_rule
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020022
Vuln IDs
  • V-248664
Rule IDs
  • SV-248664r853787_rule
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. OL 8 can use the "pam_faillock.so" for this purpose. Note that manual changes to the listed files may be overwritten by the "authselect" program. From "Pam_Faillock" man pages: Note that the default directory that "pam_faillock" uses is usually cleared on system boot so the access will be reenabled after system reboot. If that is undesirable, a different tally directory must be set with the "dir" option. Satisfies: SRG-OS-000021-GPOS-00005, SRG-OS-000329-GPOS-00128
Checks: C-52098r779556_chk

Verify the system includes the root account when locking an account after three unsuccessful logon attempts within a period of 15 minutes with the following commands. Note: If the System Administrator demonstrates the use of an approved centralized account management method that locks an account after three unsuccessful logon attempts within a period of 15 minutes, this requirement is not applicable. Note: This check applies to OL versions 8.0 and 8.1. If the system is OL version 8.2 or newer, this check is not applicable. $ sudo grep pam_faillock.so /etc/pam.d/password-auth auth required pam_faillock.so preauth dir=/var/log/faillock silent audit deny=3 even_deny_root fail_interval=900 unlock_time=0 auth required pam_faillock.so authfail dir=/var/log/faillock unlock_time=0 account required pam_faillock.so If the "even_deny_root" option is missing from the "preauth" line with the "pam_faillock.so" module, this is a finding. $ sudo grep pam_faillock.so /etc/pam.d/system-auth auth required pam_faillock.so preauth dir=/var/log/faillock silent audit deny=3 even_deny_root fail_interval=900 unlock_time=0 auth required pam_faillock.so authfail dir=/var/log/faillock unlock_time=0 account required pam_faillock.so If the "even_deny_root" option is missing from the "preauth" line with the "pam_faillock.so" module, this is a finding.

Fix: F-52052r779557_fix

Configure the operating system to include root when locking an account after three unsuccessful logon attempts occur in 15 minutes. Add/modify the appropriate sections of the "/etc/pam.d/system-auth" and "/etc/pam.d/password-auth" files to match the following lines: auth required pam_faillock.so preauth dir=/var/log/faillock silent audit deny=3 even_deny_root fail_interval=900 unlock_time=0 auth required pam_faillock.so authfail dir=/var/log/faillock unlock_time=0 account required pam_faillock.so The "sssd" service must be restarted for the changes to take effect. To restart the "sssd" service, run the following command: $ sudo systemctl restart sssd.service

b
OL 8 systems, versions 8.2 and above, must include root when automatically locking an account until the locked account is released by an administrator when three unsuccessful logon attempts occur during a 15-minute time period.
AC-7 - Medium - CCI-000044 - V-248665 - SV-248665r853788_rule
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020023
Vuln IDs
  • V-248665
Rule IDs
  • SV-248665r853788_rule
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. In OL 8.2, the "/etc/security/faillock.conf" file was incorporated to centralize the configuration of the "pam_faillock.so" module. Also introduced is a "local_users_only" option that will only track failed user authentication attempts for local users in /etc/passwd and ignore centralized (AD, IdM, LDAP, etc.) users to allow the centralized platform to solely manage user lockout. From "faillock.conf" man pages: Note that the default directory that "pam_faillock" uses is usually cleared on system boot so the access will be reenabled after system reboot. If that is undesirable, a different tally directory must be set with the "dir" option. Satisfies: SRG-OS-000021-GPOS-00005, SRG-OS-000329-GPOS-00128
Checks: C-52099r779559_chk

Note: This check applies to OL versions 8.2 or newer. If the system is OL version 8.0 or 8.1, this check is not applicable. Verify the "/etc/security/faillock.conf" file is configured to log user name information when unsuccessful logon attempts occur: $ sudo grep even_deny_root /etc/security/faillock.conf even_deny_root If the "even_deny_root" option is not set or is missing or commented out, this is a finding.

Fix: F-52053r779560_fix

Configure the operating system to include root when locking an account after three unsuccessful logon attempts occur in 15 minutes. Add/modify the "/etc/security/faillock.conf" file to match the following line: even_deny_root

a
OL 8 must limit the number of concurrent sessions to 10 for all accounts and/or account types.
AC-10 - Low - CCI-000054 - V-248666 - SV-248666r877399_rule
RMF Control
AC-10
Severity
Low
CCI
CCI-000054
Version
OL08-00-020024
Vuln IDs
  • V-248666
Rule IDs
  • SV-248666r877399_rule
Operating system management includes the ability to control the number of users and user sessions that use an operating system. Limiting the number of allowed users and sessions per user is helpful in reducing the risks related to denial-of-service attacks. This requirement addresses concurrent sessions for information system accounts and does not address concurrent sessions by single users via multiple system accounts. The maximum number of concurrent sessions should be defined based on mission needs and the operational environment for each system.
Checks: C-52100r779562_chk

Verify the operating system limits the number of concurrent sessions to 10 for all accounts and/or account types by issuing the following command: $ sudo grep "maxlogins" /etc/security/limits.conf /etc/security/limits.d/*.conf * hard maxlogins 10 This can be set as a global domain (with the * wildcard) but may be set differently for multiple domains. If the "maxlogins" item is missing or commented out, or the value is not set to "10" or less for all domains that have the "maxlogins" item assigned, this is a finding.

Fix: F-52054r779563_fix

Configure OL 8 to limit the number of concurrent sessions to 10 for all accounts and/or account types. Add the following line to the top of "/etc/security/limits.conf" or in a ".conf" file defined in "/etc/security/limits.d/": * hard maxlogins 10

b
OL 8 must configure the use of the pam_faillock.so module in the /etc/pam.d/system-auth file.
AC-7 - Medium - CCI-000044 - V-248667 - SV-248667r853789_rule
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020025
Vuln IDs
  • V-248667
Rule IDs
  • SV-248667r853789_rule
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. In OL 8.2 the "/etc/security/faillock.conf" file was incorporated to centralize the configuration of the pam_faillock.so module. Also introduced is a "local_users_only" option that will only track failed user authentication attempts for local users in /etc/passwd and ignore centralized (AD, IdM, LDAP, etc.) users to allow the centralized platform to solely manage user lockout. From "faillock.conf" man pages: Note that the default directory that "pam_faillock" uses is usually cleared on system boot so the access will be reenabled after system reboot. If that is undesirable a different tally directory must be set with the "dir" option. The preauth argument must be used when the module is called before the modules that ask for user credentials, such as the password. Satisfies: SRG-OS-000021-GPOS-00005, SRG-OS-000329-GPOS-00128
Checks: C-52101r779565_chk

Note: This check applies to OL versions 8.2 or newer, if the system is OL version 8.0 or 8.1, this check is not applicable. Verify the pam_faillock.so module is present in the "/etc/pam.d/system-auth" file: $ sudo grep pam_faillock.so /etc/pam.d/system-auth auth required pam_faillock.so preauth auth required pam_faillock.so authfail account required pam_faillock.so If the pam_faillock.so module is not present in the "/etc/pam.d/system-auth" file with the "preauth" line listed before pam_unix.so, this is a finding.

Fix: F-52055r779566_fix

Configure the operating system to include the use of the pam_faillock.so module in the /etc/pam.d/system-auth file. Add/Modify the appropriate sections of the "/etc/pam.d/system-auth" file to match the following lines: Note: The "preauth" line must be listed before pam_unix.so. auth required pam_faillock.so preauth auth required pam_faillock.so authfail account required pam_faillock.so

b
OL 8 must configure the use of the pam_faillock.so module in the /etc/pam.d/password-auth file.
AC-7 - Medium - CCI-000044 - V-248668 - SV-248668r853790_rule
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020026
Vuln IDs
  • V-248668
Rule IDs
  • SV-248668r853790_rule
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. In OL 8.2 the "/etc/security/faillock.conf" file was incorporated to centralize the configuration of the pam_faillock.so module. Also introduced is a "local_users_only" option that will only track failed user authentication attempts for local users in /etc/passwd and ignore centralized (AD, IdM, LDAP, etc.) users to allow the centralized platform to solely manage user lockout. From "faillock.conf" man pages: Note that the default directory that "pam_faillock" uses is usually cleared on system boot so the access will be reenabled after system reboot. If that is undesirable a different tally directory must be set with the "dir" option. The preauth argument must be used when the module is called before the modules that ask for user credentials, such as the password. Satisfies: SRG-OS-000021-GPOS-00005, SRG-OS-000329-GPOS-00128
Checks: C-52102r779568_chk

Note: This check applies to OL versions 8.2 or newer, if the system is OL version 8.0 or 8.1, this check is not applicable. Verify the pam_faillock.so module is present in the "/etc/pam.d/password-auth" file: $ sudo grep pam_faillock.so /etc/pam.d/password-auth auth required pam_faillock.so preauth auth required pam_faillock.so authfail account required pam_faillock.so If the pam_faillock.so module is not present in the "/etc/pam.d/password-auth" file with the "preauth" line listed before pam_unix.so, this is a finding.

Fix: F-52056r779569_fix

Configure the operating system to include the use of the pam_faillock.so module in the /etc/pam.d/password-auth file. Add/Modify the appropriate sections of the "/etc/pam.d/password-auth" file to match the following lines: Note: The "preauth" line must be listed before pam_unix.so. auth required pam_faillock.so preauth auth required pam_faillock.so authfail account required pam_faillock.so

b
OL 8 systems, versions 8.2 and above, must configure SELinux context type to allow the use of a non-default faillock tally directory.
AC-7 - Medium - CCI-000044 - V-248669 - SV-248669r853791_rule
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020027
Vuln IDs
  • V-248669
Rule IDs
  • SV-248669r853791_rule
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. From "faillock.conf" man pages: Note that the default directory that "pam_faillock" uses is usually cleared on system boot so the access will be re-enabled after system reboot. If that is undesirable, a different tally directory must be set with the "dir" option. SELinux, enforcing a targeted policy, will require any non-default tally directory's security context type to match the default directory's security context type. Without updating the security context type, the pam_faillock module will not write failed login attempts to the non-default tally directory. Satisfies: SRG-OS-000021-GPOS-00005, SRG-OS-000329-GPOS-00128
Checks: C-52103r779571_chk

If the system does not have SELinux enabled and enforcing a targeted policy, or if the pam_faillock module is not configured for use, this requirement is not applicable. Note: This check applies to OL versions 8.2 or newer. If the system is OL version 8.0 or 8.1, this check is not applicable. Verify the location of the non-default tally directory for the pam_faillock module with the following command: $ sudo grep -w dir /etc/security/faillock.conf dir = /var/log/faillock Check the security context type of the non-default tally directory with the following command: $ sudo ls -Zd /var/log/faillock unconfined_u:object_r:faillog_t:s0 /var/log/faillock If the security context type of the non-default tally directory is not "faillog_t", this is a finding.

Fix: F-52057r779572_fix

Configure OL 8 to allow the use of a non-default faillock tally directory while SELinux enforces a targeted policy. Create a non-default faillock tally directory (if it does not already exist) with the following example: $ sudo mkdir /var/log/faillock Update the /etc/selinux/targeted/contexts/files/file_contexts.local with "faillog_t" context type for the non-default faillock tally directory with the following command: $ sudo semanage fcontext -a -t faillog_t "/var/log/faillock(/.*)?" Next, update the context type of the non-default faillock directory/subdirectories and files with the following command: $ sudo restorecon -R -v /var/log/faillock

b
OL 8 systems below version 8.2 must configure SELinux context type to allow the use of a non-default faillock tally directory.
AC-7 - Medium - CCI-000044 - V-248670 - SV-248670r853792_rule
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020028
Vuln IDs
  • V-248670
Rule IDs
  • SV-248670r853792_rule
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. From "Pam_Faillock" man pages: Note that the default directory that "pam_faillock" uses is usually cleared on system boot so the access will be reenabled after system reboot. If that is undesirable, a different tally directory must be set with the "dir" option. SELinux, enforcing a targeted policy, will require any non-default tally directory's security context type to match the default directory's security context type. Without updating the security context type, the pam_faillock module will not write failed login attempts to the non-default tally directory. Satisfies: SRG-OS-000021-GPOS-00005, SRG-OS-000329-GPOS-00128
Checks: C-52104r779574_chk

If the system does not have SELinux enabled and enforcing a targeted policy, or if the pam_faillock module is not configured for use, this requirement is not applicable. Note: This check applies to OL versions 8.0 and 8.1. If the system is OL version 8.2 or newer, this check is not applicable. Verify the location of the non-default tally directory for the pam_faillock module with the following command: $ sudo grep -w dir /etc/pam.d/password-auth auth required pam_faillock.so preauth dir=/var/log/faillock auth required pam_faillock.so authfail dir=/var/log/faillock Check the security context type of the non-default tally directory with the following command: $ sudo ls -Zd /var/log/faillock unconfined_u:object_r:faillog_t:s0 /var/log/faillock If the security context type of the non-default tally directory is not "faillog_t", this is a finding.

Fix: F-52058r779575_fix

Configure OL 8 to allow the use of a non-default faillock tally directory while SELinux enforces a targeted policy. Update the /etc/selinux/targeted/contexts/files/file_contexts.local with "faillog_t" context type for the non-default faillock tally directory with the following command: $ sudo semanage fcontext -a -t faillog_t "/var/log/faillock(/.*)?" Next, update the context type of the non-default faillock directory/subdirectories and files with the following command: $ sudo restorecon -R -v /var/log/faillock

b
OL 8 must enable a user session lock until that user reestablishes access using established identification and authentication procedures for graphical user sessions.
AC-11 - Medium - CCI-000056 - V-248671 - SV-248671r779579_rule
RMF Control
AC-11
Severity
Medium
CCI
CCI-000056
Version
OL08-00-020030
Vuln IDs
  • V-248671
Rule IDs
  • SV-248671r779579_rule
To establish acceptance of the application usage policy, a click-through banner at system logon is required. The system must prevent further activity until the user executes a positive action to manifest agreement by clicking on a box indicating "OK". Satisfies: SRG-OS-000028-GPOS-00009, SRG-OS-000030-GPOS-00011
Checks: C-52105r779577_chk

Note: This requirement assumes the use of the OL 8 default graphical user interface, Gnome Shell. If the system does not have any graphical user interface installed, this requirement is Not Applicable. Verify the operating system enables a user's session lock until that user reestablishes access using established identification and authentication procedures with the following command: $ sudo gsettings get org.gnome.desktop.screensaver lock-enabled true If the setting is "false", this is a finding.

Fix: F-52059r779578_fix

Configure OL 8 to enable a user's session lock until that user reestablishes access using established identification and authentication procedures. Create a database to contain the system-wide screensaver settings (if it does not already exist) with the following example: $ sudo vi /etc/dconf/db/local.d/00-screensaver Edit the "[org/gnome/desktop/screensaver]" section of the database file and add or update the following lines: # Set this to true to lock the screen when the screensaver activates lock-enabled=true Update the system databases: $ sudo dconf update

b
OL 8 must initiate a session lock for graphical user interfaces when the screensaver is activated.
AC-11 - Medium - CCI-000057 - V-248672 - SV-248672r779582_rule
RMF Control
AC-11
Severity
Medium
CCI
CCI-000057
Version
OL08-00-020031
Vuln IDs
  • V-248672
Rule IDs
  • SV-248672r779582_rule
A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not log out because of the temporary nature of the absence. Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity, operating systems need to be able to identify when a user's session has idled and take action to initiate the session lock. The session lock is implemented at the point where session activity can be determined and/or controlled. Satisfies: SRG-OS-000029-GPOS-00010, SRG-OS-000031-GPOS-00012
Checks: C-52106r779580_chk

Note: This requirement assumes the use of the OL 8 default graphical user interface, Gnome Shell. If the system does not have any graphical user interface installed, this requirement is Not Applicable. Verify the operating system initiates a session lock a for graphical user interfaces when the screensaver is activated with the following command: $ sudo gsettings get org.gnome.desktop.screensaver lock-delay uint32 5 If the "uint32" setting is missing, or is not set to "5" or less, this is a finding.

Fix: F-52060r779581_fix

Configure the operating system to initiate a session lock for graphical user interfaces when a screensaver is activated. Create a database to contain the system-wide screensaver settings (if it does not already exist) with the following command: Note: The example below is using the database "local" for the system, so if the system is using another database in "/etc/dconf/profile/user", the file should be created under the appropriate subdirectory. $ sudo touch /etc/dconf/db/local.d/00-screensaver [org/gnome/desktop/screensaver] lock-delay=uint32 5 The "uint32" must be included along with the integer key values as shown. Update the system databases: $ sudo dconf update

b
OL 8 must disable the user list at logon for graphical user interfaces.
CM-6 - Medium - CCI-000366 - V-248673 - SV-248673r779585_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-020032
Vuln IDs
  • V-248673
Rule IDs
  • SV-248673r779585_rule
Leaving the user list enabled is a security risk since it allows anyone with physical access to the system to enumerate known user accounts without authenticated access to the system.
Checks: C-52107r779583_chk

Note: This requirement assumes the use of the OL 8 default graphical user interface, Gnome Shell. If the system does not have any graphical user interface installed, this requirement is Not Applicable. Verify the operating system disables the user logon list for graphical user interfaces with the following command: $ sudo gsettings get org.gnome.login-screen disable-user-list true If the setting is "false", this is a finding.

Fix: F-52061r779584_fix

Configure the operating system to disable the user list at logon for graphical user interfaces. Create a database to contain the system-wide screensaver settings (if it does not already exist) with the following command: Note: The example below is using the database "local" for the system, so if the system is using another database in "/etc/dconf/profile/user", the file should be created under the appropriate subdirectory. $ sudo touch /etc/dconf/db/local.d/02-login-screen [org/gnome/login-screen] disable-user-list=true Update the system databases: $ sudo dconf update

b
OL 8 must have the tmux package installed.
AC-11 - Medium - CCI-000056 - V-248674 - SV-248674r779588_rule
RMF Control
AC-11
Severity
Medium
CCI
CCI-000056
Version
OL08-00-020039
Vuln IDs
  • V-248674
Rule IDs
  • SV-248674r779588_rule
A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. Rather than be forced to wait for a period of time to expire before the user session can be locked, OL 8 needs to provide users with the ability to manually invoke a session lock so users can secure their session if it is necessary to temporarily vacate the immediate physical vicinity. Tmux is a terminal multiplexer that enables a number of terminals to be created, accessed, and controlled from a single screen. Satisfies: SRG-OS-000028-GPOS-00009, SRG-OS-000030-GPOS-00011
Checks: C-52108r779586_chk

Verify OL 8 has the "tmux" package installed, by running the following command: $ sudo yum list installed tmux tmux.x86.64 2.7-1.el8 @repository If "tmux" is not installed, this is a finding.

Fix: F-52062r779587_fix

Configure the operating system to enable a user to initiate a session lock via tmux. Install the "tmux" package, if it is not already installed, by running the following command: $ sudo yum install tmux

b
OL 8 must enable a user session lock until that user re-establishes access using established identification and authentication procedures for command line sessions.
AC-11 - Medium - CCI-000056 - V-248675 - SV-248675r902786_rule
RMF Control
AC-11
Severity
Medium
CCI
CCI-000056
Version
OL08-00-020040
Vuln IDs
  • V-248675
Rule IDs
  • SV-248675r902786_rule
A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. Rather than be forced to wait for a period of time to expire before the user session can be locked, OL 8 needs to provide users with the ability to manually invoke a session lock so users can secure their session if it is necessary to temporarily vacate the immediate physical vicinity. Tmux is a terminal multiplexer that enables a number of terminals to be created, accessed, and controlled from a single screen. Satisfies: SRG-OS-000028-GPOS-00009, SRG-OS-000030-GPOS-00011
Checks: C-52109r902785_chk

Verify the operating system enables the user to manually initiate a session lock with the following command: $ sudo grep -Ei 'lock-command|lock-session' /etc/tmux.conf set -g lock-command vlock bind X lock-session If the "lock-command" is not set and "lock-session" is not bound to a specific keyboard key in the global settings, this is a finding.

Fix: F-52063r880563_fix

Configure the operating system to enable a user to manually initiate a session lock via tmux. This configuration binds the uppercase letter "X" to manually initiate a session lock after the prefix key "Ctrl + b" has been sent. The complete key sequence is thus "Ctrl + b" then "Shift + x" to lock tmux. Create a global configuration file "/etc/tmux.conf" and add the following lines: set -g lock-command vlock bind X lock-session Reload tmux configuration to take effect. This can be performed in tmux while it is running: $ tmux source-file /etc/tmux.conf

b
OL 8 must ensure session control is automatically started at shell initialization.
AC-11 - Medium - CCI-000056 - V-248676 - SV-248676r917911_rule
RMF Control
AC-11
Severity
Medium
CCI
CCI-000056
Version
OL08-00-020041
Vuln IDs
  • V-248676
Rule IDs
  • SV-248676r917911_rule
Tmux is a terminal multiplexer that enables a number of terminals to be created, accessed, and controlled from a single screen. Satisfies: SRG-OS-000028-GPOS-00009, SRG-OS-000030-GPOS-00011
Checks: C-52110r880536_chk

Verify the operating system shell initialization file is configured to start each shell with the tmux terminal multiplexer with the following commands: Determine if tmux is currently running: $ sudo ps all | grep tmux | grep -v grep If the command does not produce output, this is a finding. Determine the location of the tmux script: $ sudo grep tmux /etc/profile.d/* /etc/profile.d/tmux.sh: case "$name" in (sshd|login) tmux ;; esac Review the tmux script by using the following example: $ sudo cat /etc/profile.d/tmux.sh if [ "$PS1" ]; then parent=$(ps -o ppid= -p $$) name=$(ps -o comm= -p $parent) case "$name" in (sshd|login) tmux ;; esac fi If "tmux" is not configured as the example above, is commented out or missing, this is a finding.

Fix: F-52064r880537_fix

Configure the operating system to initialize the tmux terminal multiplexer as each shell is called by adding the following lines to a custom.sh shell script in the /etc/profile.d/ directory: if [ "$PS1" ]; then parent=$(ps -o ppid= -p $$) name=$(ps -o comm= -p $parent) case "$name" in (sshd|login) tmux ;; esac fi This setting will take effect at next logon.

a
OL 8 must prevent users from disabling session control mechanisms.
AC-11 - Low - CCI-000056 - V-248677 - SV-248677r779597_rule
RMF Control
AC-11
Severity
Low
CCI
CCI-000056
Version
OL08-00-020042
Vuln IDs
  • V-248677
Rule IDs
  • SV-248677r779597_rule
A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. Rather than be forced to wait for a period of time to expire before the user session can be locked, OL 8 needs to provide users with the ability to manually invoke a session lock so users can secure their session if it is necessary to temporarily vacate the immediate physical vicinity. Tmux is a terminal multiplexer that enables a number of terminals to be created, accessed, and controlled from a single screen. Satisfies: SRG-OS-000028-GPOS-00009, SRG-OS-000030-GPOS-00011
Checks: C-52111r779595_chk

Verify the operating system prevents users from disabling the tmux terminal multiplexer with the following command: $ sudo grep -i tmux /etc/shells If any output is produced, this is a finding.

Fix: F-52065r779596_fix

Configure the operating system to prevent users from disabling the tmux terminal multiplexer by editing the "/etc/shells" configuration file to remove any instances of tmux.

b
OL 8 must enable a user session lock until that user reestablishes access using established identification and authentication procedures for command line sessions.
AC-11 - Medium - CCI-000056 - V-248678 - SV-248678r779600_rule
RMF Control
AC-11
Severity
Medium
CCI
CCI-000056
Version
OL08-00-020043
Vuln IDs
  • V-248678
Rule IDs
  • SV-248678r779600_rule
A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. Rather than be forced to wait for a period of time to expire before the user session can be locked, OL 8 needs to provide users with the ability to manually invoke a session lock so users may secure their session should the need arise for them to temporarily vacate the immediate physical vicinity. Systemd, a core component of OL 8, has a variety of dependencies needed to function. One of those packages is the Keytable files and keyboard utilities (kbd.x86_64). This package provides the "vlock" binary, a utility used to lock one or several user virtual console sessions. Satisfies: SRG-OS-000028-GPOS-00009, SRG-OS-000030-GPOS-00011
Checks: C-52112r779598_chk

Verify OL 8 has the "vlock" package installed by running the following command: $ sudo grep vlock /usr/bin/* Binary file /usr/bin/vlock matches If "vlock" is not installed, this is a finding.

Fix: F-52066r779599_fix

Install the "vlock" package, if it is not already installed, by running the following command: $ sudo yum install kbd.x86_64

b
OL 8 must be able to initiate directly a session lock for all connection types using smartcard when the smartcard is removed.
AC-11 - Medium - CCI-000056 - V-248679 - SV-248679r818655_rule
RMF Control
AC-11
Severity
Medium
CCI
CCI-000056
Version
OL08-00-020050
Vuln IDs
  • V-248679
Rule IDs
  • SV-248679r818655_rule
A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. Regardless of where the session lock is determined and implemented, once invoked, the session lock must remain in place until the user reauthenticates. No other activity aside from reauthentication must unlock the system. OL 8 includes "authselect" as a tool to configure system identity, authentication sources, and providers by selecting a specific profile. A profile is a set of files that describes the resulting system configuration. When a profile is selected, "authselect" will create the "nsswitch.conf" and "PAM" stack to use identity and authentication sources defined by the profile. Satisfies: SRG-OS-000028-GPOS-00009, SRG-OS-000030-GPOS-00011
Checks: C-52113r818654_chk

Verify the operating system enables a user's session lock until that user reestablishes access using established identification and authentication procedures with the following command: This requirement assumes the use of the OL 8 default graphical user interface, Gnome Shell. If the system does not have any graphical user interface installed, this requirement is Not Applicable. $ sudo grep -r removal-action /etc/dconf/db/* /etc/dconf/db/distro.d/20-authselect:removal-action='lock-screen' If the "removal-action='lock-screen'" setting is missing or commented out from the "dconf" database files, this is a finding.

Fix: F-52067r779602_fix

Configure OL 8 to enable a user's session lock until that user reestablishes access using established identification and authentication procedures. Select/create an "authselect" profile and incorporate the "with-smartcard-lock-on-removal" feature as in the following example: $ sudo authselect select sssd with-smartcard with-smartcard-lock-on-removal Alternatively, the "dconf" settings can be edited in the "/etc/dconf/db/*" location. Edit or add the "[org/gnome/settings-daemon/peripherals/smartcard]" section of the database file and add or update the following line: removal-action='lock-screen' Update the system databases: $ sudo dconf update

b
OL 8 must automatically lock graphical user sessions after 15 minutes of inactivity.
AC-11 - Medium - CCI-000057 - V-248680 - SV-248680r779606_rule
RMF Control
AC-11
Severity
Medium
CCI
CCI-000057
Version
OL08-00-020060
Vuln IDs
  • V-248680
Rule IDs
  • SV-248680r779606_rule
A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not log out because of the temporary nature of the absence. Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity, operating systems must be able to identify when a user's session has idled and take action to initiate the session lock. The session lock is implemented at the point where session activity can be determined and/or controlled. Satisfies: SRG-OS-000029-GPOS-00010, SRG-OS-000031-GPOS-00012
Checks: C-52114r779604_chk

Note: This requirement assumes the use of the OL 8 default graphical user interface, Gnome Shell. If the system does not have any graphical user interface installed, this requirement is Not Applicable. Verify the operating system initiates a session lock after a 15-minute period of inactivity for graphical user interfaces with the following commands: $ sudo gsettings get org.gnome.desktop.session idle-delay uint32 900 If "idle-delay" is set to "0" or a value greater than "900", this is a finding.

Fix: F-52068r779605_fix

Configure OL 8 to initiate a screensaver after a 15-minute period of inactivity for graphical user interfaces. Create a database to contain the system-wide screensaver settings (if it does not already exist) with the following command: $ sudo touch /etc/dconf/db/local.d/00-screensaver Edit "/etc/dconf/db/local.d/00-screensaver" and add or update the following lines: [org/gnome/desktop/session] # Set the lock time out to 900 seconds before the session is considered idle idle-delay=uint32 900 Update the system databases: $ sudo dconf update

b
OL 8 must automatically lock command line user sessions after 15 minutes of inactivity.
AC-11 - Medium - CCI-000057 - V-248681 - SV-248681r779609_rule
RMF Control
AC-11
Severity
Medium
CCI
CCI-000057
Version
OL08-00-020070
Vuln IDs
  • V-248681
Rule IDs
  • SV-248681r779609_rule
Terminating an idle session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been left unattended. In addition, quickly terminating an idle session will also free up resources committed by the managed network element. Terminating network connections associated with communications sessions includes, for example, de-allocating associated TCP/IP address/port pairs at the operating system level and de-allocating networking assignments at the application level if multiple application sessions are using a single operating system-level network connection. This does not mean the operating system terminates all sessions or network access; it only ends the inactive session and releases the resources associated with that session. Satisfies: SRG-OS-000029-GPOS-00010, SRG-OS-000031-GPOS-00012
Checks: C-52115r779607_chk

Verify the operating system initiates a session lock after 15 minutes of inactivity. Check the value of the system inactivity timeout with the following command: $ sudo grep -i lock-after-time /etc/tmux.conf set -g lock-after-time 900 If "lock-after-time" is not set to "900" or less in the global tmux configuration file to enforce session lock after inactivity, this is a finding.

Fix: F-52069r779608_fix

Configure the operating system to enforce session lock after a period of 15 minutes of inactivity by adding the following line to the "/etc/tmux.conf" global configuration file: set -g lock-after-time 900

b
OL 8 must prevent a user from overriding the session lock-delay setting for the graphical user interface.
AC-11 - Medium - CCI-000057 - V-248682 - SV-248682r779612_rule
RMF Control
AC-11
Severity
Medium
CCI
CCI-000057
Version
OL08-00-020080
Vuln IDs
  • V-248682
Rule IDs
  • SV-248682r779612_rule
A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not log out because of the temporary nature of the absence. Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity, operating systems need to be able to identify when a user's session has idled and take action to initiate the session lock. The session lock is implemented at the point where session activity can be determined and/or controlled. Implementing session settings will have little value if a user is able to manipulate these settings from the defaults prescribed in the other requirements of this implementation guide. Locking these settings from non-privileged users is crucial to maintaining a protected baseline. Satisfies: SRG-OS-000029-GPOS-00010, SRG-OS-000031-GPOS-00012
Checks: C-52116r779610_chk

Note: This requirement assumes the use of the OL 8 default graphical user interface, Gnome Shell. If the system does not have any graphical user interface installed, this requirement is Not Applicable. Verify the operating system prevents a user from overriding settings for graphical user interfaces. Determine which profile the system database is using with the following command: $ sudo grep system-db /etc/dconf/profile/user system-db:local Check that graphical settings are locked from non-privileged user modification with the following command. Note: The example below is using the database "local" for the system, so the path is "/etc/dconf/db/local.d". This path must be modified if a database other than "local" is being used. $ sudo grep -i lock-delay /etc/dconf/db/local.d/locks/* /org/gnome/desktop/screensaver/lock-delay If the command does not return at least the example result, this is a finding.

Fix: F-52070r779611_fix

Configure OL 8 to prevent a user from overriding settings for graphical user interfaces. Create a database to contain the system-wide screensaver settings (if it does not already exist) with the following command. Note: The example below is using the database "local" for the system, so if the system is using another database in "/etc/dconf/profile/user", the file should be created under the appropriate subdirectory. $ sudo touch /etc/dconf/db/local.d/locks/session Add the following setting to prevent non-privileged users from modifying it: /org/gnome/desktop/screensaver/lock-delay

b
OL 8 must prevent a user from overriding the session idle-delay setting for the graphical user interface.
AC-11 - Medium - CCI-000057 - V-248683 - SV-248683r779615_rule
RMF Control
AC-11
Severity
Medium
CCI
CCI-000057
Version
OL08-00-020081
Vuln IDs
  • V-248683
Rule IDs
  • SV-248683r779615_rule
A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not log out because of the temporary nature of the absence. Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity, operating systems need to be able to identify when a user's session has idled and take action to initiate the session lock. The session lock is implemented at the point where session activity can be determined and/or controlled. Implementing session settings will have little value if a user is able to manipulate these settings from the defaults prescribed in the other requirements of this implementation guide. Locking these settings from non-privileged users is crucial to maintaining a protected baseline. Satisfies: SRG-OS-000029-GPOS-00010, SRG-OS-000031-GPOS-00012
Checks: C-52117r779613_chk

Note: This requirement assumes the use of the OL 8 default graphical user interface, Gnome Shell. If the system does not have any graphical user interface installed, this requirement is Not Applicable. Verify the operating system prevents a user from overriding settings for graphical user interfaces. Determine which profile the system database is using with the following command: $ sudo grep system-db /etc/dconf/profile/user system-db:local Check that graphical settings are locked from non-privileged user modification with the following command. Note: The example below is using the database "local" for the system, so the path is "/etc/dconf/db/local.d". This path must be modified if a database other than "local" is being used. $ sudo grep -i idle /etc/dconf/db/local.d/locks/* /org/gnome/desktop/screensaver/idle-delay If the command does not return at least the example result, this is a finding.

Fix: F-52071r779614_fix

Configure OL 8 to prevent a user from overriding settings for graphical user interfaces. Create a database to contain the system-wide screensaver settings (if it does not already exist) with the following command. Note: The example below is using the database "local" for the system, so if the system is using another database in "/etc/dconf/profile/user", the file should be created under the appropriate subdirectory. $ sudo touch /etc/dconf/db/local.d/locks/session Add the following setting to prevent non-privileged users from modifying it: /org/gnome/desktop/screensaver/idle-delay

b
OL 8 must prevent a user from overriding the session lock-enabled setting for the graphical user interface.
AC-11 - Medium - CCI-000057 - V-248684 - SV-248684r779618_rule
RMF Control
AC-11
Severity
Medium
CCI
CCI-000057
Version
OL08-00-020082
Vuln IDs
  • V-248684
Rule IDs
  • SV-248684r779618_rule
A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not log out because of the temporary nature of the absence. Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity, operating systems need to be able to identify when a user's session has idled and take action to initiate the session lock. The session lock is implemented at the point where session activity can be determined and/or controlled. Implementing session settings will have little value if a user is able to manipulate these settings from the defaults prescribed in the other requirements of this implementation guide. Locking these settings from non-privileged users is crucial to maintaining a protected baseline. Satisfies: SRG-OS-000029-GPOS-00010, SRG-OS-000031-GPOS-00012
Checks: C-52118r779616_chk

Note: This requirement assumes the use of the OL 8 default graphical user interface, Gnome Shell. If the system does not have any graphical user interface installed, this requirement is Not Applicable. Verify the operating system prevents a user from overriding settings for graphical user interfaces. Determine which profile the system database is using with the following command: $ sudo grep system-db /etc/dconf/profile/user system-db:local Check that graphical settings are locked from non-privileged user modification with the following command. Note: The example below is using the database "local" for the system, so the path is "/etc/dconf/db/local.d". This path must be modified if a database other than "local" is being used. $ sudo grep -i lock-enabled /etc/dconf/db/local.d/locks/* /org/gnome/desktop/screensaver/lock-enabled If the command does not return at least the example result, this is a finding.

Fix: F-52072r779617_fix

Configure OL 8 to prevent a user from overriding settings for graphical user interfaces. Create a database to contain the system-wide screensaver settings (if it does not already exist) with the following command. Note: The example below is using the database "local" for the system, so if the system is using another database in "/etc/dconf/profile/user", the file should be created under the appropriate subdirectory. $ sudo touch /etc/dconf/db/local.d/locks/session Add the following setting to prevent non-privileged users from modifying it: /org/gnome/desktop/screensaver/lock-enabled

b
OL 8 must map the authenticated identity to the user or group account for PKI-based authentication.
IA-5 - Medium - CCI-000187 - V-248685 - SV-248685r858606_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000187
Version
OL08-00-020090
Vuln IDs
  • V-248685
Rule IDs
  • SV-248685r858606_rule
Without mapping the certificate used to authenticate to the user account, the ability to determine the identity of the individual user or group will not be available for forensic analysis. There are various methods of mapping certificates to user/group accounts for OL 8. For the purposes of this requirement, the check and fix will account for Active Directory mapping. Some of the other possible methods include joining the system to a domain and using an idM server, or a local system mapping, where the system is not part of a domain.
Checks: C-52119r858605_chk

Verify the certificate of the user or group is mapped to the corresponding user or group in the "sssd.conf" file with the following command: Note: If the System Administrator demonstrates the use of an approved alternate multifactor authentication method, this requirement is not applicable. $ sudo cat /etc/sssd/sssd.conf [sssd] config_file_version = 2 services = pam, sudo, ssh domains = testing.test [pam] pam_cert_auth = True [domain/testing.test] id_provider = ldap [certmap/testing.test/rule_name] matchrule =&lt;SAN&gt;.*EDIPI@mil maprule = (userCertificate;binary={cert!bin}) domains = testing.test If the "certmap" section does not exist, this is a finding.

Fix: F-52073r779620_fix

Configure OL 8 to map the authenticated identity to the user or group account by adding or modifying the "certmap" section of the "/etc/sssd/sssd.conf" file based on the following example: [certmap/testing.test/rule_name] matchrule =<SAN>.*EDIPI@mil maprule = (userCertificate;binary={cert!bin}) domains = testing.test The "sssd" service must be restarted for the changes to take effect. To restart the "sssd" service, run the following command: $ sudo systemctl restart sssd.service

b
OL 8 must ensure the password complexity module is enabled in the password-auth file.
CM-6 - Medium - CCI-000366 - V-248686 - SV-248686r902809_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-020100
Vuln IDs
  • V-248686
Rule IDs
  • SV-248686r902809_rule
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Use of "pwquality" enforces complex password construction configuration and has the ability to limit brute-force attacks on the system. OL 8 uses "pwquality" as a mechanism to enforce password complexity. This is set in both of the following: /etc/pam.d/password-auth /etc/pam.d/system-auth Satisfies: SRG-OS-000069-GPOS-00037, SRG-OS-000070-GPOS-00038
Checks: C-52120r902807_chk

Verify the operating system uses "pwquality" to enforce the password complexity rules. Check for the use of "pwquality" in the password-auth file with the following command: $ sudo cat /etc/pam.d/password-auth | grep pam_pwquality password requisite pam_pwquality.so If the command does not return a line containing the value "pam_pwquality.so" as shown, or the line is commented out, this is a finding.

Fix: F-52074r902808_fix

Configure the operating system to use "pwquality" to enforce password complexity rules. Add the following line to the "/etc/pam.d/password-auth" file (or modify the line to have the required value): password requisite pam_pwquality.so

a
OL 8 must enforce password complexity by requiring that at least one uppercase character be used.
IA-5 - Low - CCI-000192 - V-248687 - SV-248687r858631_rule
RMF Control
IA-5
Severity
Low
CCI
CCI-000192
Version
OL08-00-020110
Vuln IDs
  • V-248687
Rule IDs
  • SV-248687r858631_rule
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. OL 8 uses pwquality as a mechanism to enforce password complexity. Note that in order to require uppercase characters without degrading the "minlen" value, the credit value must be expressed as a negative number in "/etc/security/pwquality.conf". Satisfies: SRG-OS-000069-GPOS-00037, SRG-OS-000070-GPOS-00038
Checks: C-52121r833219_chk

Verify the value for "ucredit" in "/etc/security/pwquality.conf" or "/etc/security/pwquality.conf.d/*.conf" files with the following command: $ sudo grep -r ucredit /etc/security/pwquality.conf* /etc/security/pwquality.conf:ucredit = -1 If the value of "ucredit" is a positive number or is commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52075r858630_fix

Configure OL 8 to enforce password complexity by requiring that at least one uppercase character be used by setting the "ucredit" option. Add or update the following line in the "/etc/security/pwquality.conf" file or a configuration file in the "/etc/security/pwquality.conf.d/" directory: ucredit = -1 Remove any configurations that conflict with the above value.

a
OL 8 must enforce password complexity by requiring that at least one lowercase character be used.
IA-5 - Low - CCI-000193 - V-248688 - SV-248688r858633_rule
RMF Control
IA-5
Severity
Low
CCI
CCI-000193
Version
OL08-00-020120
Vuln IDs
  • V-248688
Rule IDs
  • SV-248688r858633_rule
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. OL 8 uses pwquality as a mechanism to enforce password complexity. Note that in order to require lowercase characters without degrading the "minlen" value, the credit value must be expressed as a negative number in "/etc/security/pwquality.conf".
Checks: C-52122r833221_chk

Verify the value for "lcredit" in "/etc/security/pwquality.conf" or "/etc/security/pwquality.conf.d/*.conf" files with the following command: $ sudo grep -r lcredit /etc/security/pwquality.conf* /etc/security/pwquality.conf:lcredit = -1 If the value of "lcredit" is a positive number or is commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52076r858632_fix

Configure OL 8 to enforce password complexity by requiring that at least one lowercase character be used by setting the "lcredit" option. Add or update the following line in the "/etc/security/pwquality.conf" file or a configuration file in the "/etc/security/pwquality.conf.d/" directory: lcredit = -1 Remove any configurations that conflict with the above value.

a
OL 8 must enforce password complexity by requiring that at least one numeric character be used.
IA-5 - Low - CCI-000194 - V-248689 - SV-248689r858635_rule
RMF Control
IA-5
Severity
Low
CCI
CCI-000194
Version
OL08-00-020130
Vuln IDs
  • V-248689
Rule IDs
  • SV-248689r858635_rule
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. OL 8 uses "pwquality" as a mechanism to enforce password complexity. Note that in order to require numeric characters without degrading the minlen value, the credit value must be expressed as a negative number in "/etc/security/pwquality.conf".
Checks: C-52123r833223_chk

Verify the value for "dcredit" in "/etc/security/pwquality.conf" or "/etc/security/pwquality.conf.d/*.conf" files with the following command: $ sudo grep -r dcredit /etc/security/pwquality.conf* /etc/security/pwquality.conf:dcredit = -1 If the value of "dcredit" is a positive number or is commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52077r858634_fix

Configure OL 8 to enforce password complexity by requiring that at least one numeric character be used by setting the "dcredit" option. Add or update the following line in the "/etc/security/pwquality.conf" file or a configuration file in the "/etc/security/pwquality.conf.d/" directory: dcredit = -1 Remove any configurations that conflict with the above value.

b
OL 8 must require the maximum number of repeating characters of the same character class be limited to four when passwords are changed.
IA-5 - Medium - CCI-000195 - V-248690 - SV-248690r858637_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000195
Version
OL08-00-020140
Vuln IDs
  • V-248690
Rule IDs
  • SV-248690r858637_rule
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. OL 8 uses "pwquality" as a mechanism to enforce password complexity. The "maxclassrepeat" option sets the maximum number of allowed same consecutive characters in the same class in the new password.
Checks: C-52124r833225_chk

Check for the value of the "maxclassrepeat" option in "/etc/security/pwquality.conf" or "/etc/security/pwquality.conf.d/*.conf" files with the following command: $ sudo grep -r maxclassrepeat /etc/security/pwquality.conf* /etc/security/pwquality.conf:maxclassrepeat = 4 If the value of "maxclassrepeat" is set to "0", more than "4" or is commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52078r858636_fix

Configure OL 8 to require the change of the number of repeating characters of the same character class when passwords are changed by setting the "maxclassrepeat" option. Add or update the following line in the "/etc/security/pwquality.conf" file or a configuration file in the "/etc/security/pwquality.conf.d/" directory: maxclassrepeat = 4 Remove any configurations that conflict with the above value.

b
OL 8 must require the maximum number of repeating characters be limited to three when passwords are changed.
IA-5 - Medium - CCI-000195 - V-248691 - SV-248691r858639_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000195
Version
OL08-00-020150
Vuln IDs
  • V-248691
Rule IDs
  • SV-248691r858639_rule
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. OL 8 uses "pwquality" as a mechanism to enforce password complexity. The "maxrepeat" option sets the maximum number of allowed same consecutive characters in a new password.
Checks: C-52125r833227_chk

Check for the value of the "maxrepeat" option in "/etc/security/pwquality.conf" or "/etc/security/pwquality.conf.d/*.conf" files with the following command: $ sudo grep -r maxrepeat /etc/security/pwquality.conf* /etc/security/pwquality.conf:maxrepeat = 3 If the value of "maxrepeat" is set to more than "3" or is commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52079r858638_fix

Configure OL 8 to require the change of the number of repeating consecutive characters when passwords are changed by setting the "maxrepeat" option. Add or update the following line in the "/etc/security/pwquality.conf" file or a configuration file in the "/etc/security/pwquality.conf.d/" directory: maxrepeat = 3 Remove any configurations that conflict with the above value.

b
OL 8 must require the change of at least four character classes when passwords are changed.
IA-5 - Medium - CCI-000195 - V-248692 - SV-248692r858641_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000195
Version
OL08-00-020160
Vuln IDs
  • V-248692
Rule IDs
  • SV-248692r858641_rule
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. OL 8 uses "pwquality" as a mechanism to enforce password complexity. The "minclass" option sets the minimum number of required classes of characters for the new password (digits, upper-case, lower-case, others).
Checks: C-52126r833229_chk

Verify the value of the "minclass" option in "/etc/security/pwquality.conf" or "/etc/security/pwquality.conf.d/*.conf" files with the following command: $ sudo grep -r minclass /etc/security/pwquality.conf* /etc/security/pwquality.conf:minclass = 4 If the value of "minclass" is set to less than "4" or is commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52080r858640_fix

Configure OL 8 to require the change of at least four character classes when passwords are changed by setting the "minclass" option. Add or update the following line in the "/etc/security/pwquality.conf" file or a configuration file in the "/etc/security/pwquality.conf.d/" directory: minclass = 4 Remove any configurations that conflict with the above value.

a
OL 8 must require the change of at least 8 characters when passwords are changed.
IA-5 - Low - CCI-000195 - V-248693 - SV-248693r858643_rule
RMF Control
IA-5
Severity
Low
CCI
CCI-000195
Version
OL08-00-020170
Vuln IDs
  • V-248693
Rule IDs
  • SV-248693r858643_rule
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. OL 8 uses "pwquality" as a mechanism to enforce password complexity. The "difok" option sets the number of characters in a password that must not be present in the old password.
Checks: C-52127r833231_chk

Verify the value of the "difok" option in "/etc/security/pwquality.conf" or "/etc/security/pwquality.conf.d/*.conf" files with the following command: $ sudo grep -r difok /etc/security/pwquality.conf* /etc/security/pwquality.conf:difok = 8 If the value of "difok" is set to less than "8" or is commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52081r858642_fix

Configure OL 8 to require the change of at least eight of the total number of characters when passwords are changed by setting the "difok" option. Add or update the following line in the "/etc/security/pwquality.conf" file or a configuration file in the "/etc/security/pwquality.conf.d/" directory: difok = 8 Remove any configurations that conflict with the above value.

b
OL 8 passwords for new users or password changes must have a 24 hours/1 day minimum password lifetime restriction in "/etc/shadow".
IA-5 - Medium - CCI-000198 - V-248694 - SV-248694r779648_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000198
Version
OL08-00-020180
Vuln IDs
  • V-248694
Rule IDs
  • SV-248694r779648_rule
Enforcing a minimum password lifetime helps to prevent repeated password changes to defeat the password reuse or history enforcement requirement. If users are allowed to immediately and continually change their password, the password could be repeatedly changed in a short period of time to defeat the organization's policy regarding password reuse.
Checks: C-52128r779646_chk

Verify the minimum time period between password changes for each user account is one day or greater. $ sudo awk -F: '$4 &lt; 1 {print $1 " " $4}' /etc/shadow If any results are returned that are not associated with a system account, this is a finding.

Fix: F-52082r779647_fix

Configure non-compliant accounts to enforce a 24 hours/1 day minimum password lifetime: $ sudo chage -m 1 [user]

b
OL 8 passwords for new users or password changes must have a 24 hours/1 day minimum password lifetime restriction in "/etc/login.defs".
IA-5 - Medium - CCI-000198 - V-248695 - SV-248695r858592_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000198
Version
OL08-00-020190
Vuln IDs
  • V-248695
Rule IDs
  • SV-248695r858592_rule
Enforcing a minimum password lifetime helps to prevent repeated password changes to defeat the password reuse or history enforcement requirement. If users are allowed to immediately and continually change their password, the password could be repeatedly changed in a short period of time to defeat the organization's policy regarding password reuse.
Checks: C-52129r779649_chk

Verify the operating system enforces 24 hours/1 day as the minimum password lifetime for new user accounts. Check for the value of "PASS_MIN_DAYS" in "/etc/login.defs" with the following command: $ sudo grep -i pass_min_days /etc/login.defs PASS_MIN_DAYS 1 If the "PASS_MIN_DAYS" parameter value is not "1" or greater or is commented out, this is a finding.

Fix: F-52083r779650_fix

Configure OL 8 to enforce 24 hours/1 day as the minimum password lifetime. Add the following line in "/etc/login.defs" (or modify the line to have the required value): PASS_MIN_DAYS 1

b
OL 8 user account passwords must have a 60-day maximum password lifetime restriction.
IA-5 - Medium - CCI-000199 - V-248696 - SV-248696r779654_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000199
Version
OL08-00-020200
Vuln IDs
  • V-248696
Rule IDs
  • SV-248696r779654_rule
Any password, no matter how complex, can eventually be cracked. Therefore, passwords need to be changed periodically. If OL 8 does not limit the lifetime of passwords and force users to change their passwords, there is the risk that OL 8 passwords could be compromised.
Checks: C-52130r779652_chk

Verify that OL 8 enforces a 60-day maximum password lifetime for new user accounts by running the following command: $ sudo grep -i pass_max_days /etc/login.defs PASS_MAX_DAYS 60 If the "PASS_MAX_DAYS" parameter value is greater than "60", or commented out, this is a finding.

Fix: F-52084r779653_fix

Configure OL 8 to enforce a 60-day maximum password lifetime. Add or modify the following line in the "/etc/login.defs" file: PASS_MAX_DAYS 60

b
OL 8 user account passwords must be configured so that existing passwords are restricted to a 60-day maximum lifetime.
IA-5 - Medium - CCI-000199 - V-248697 - SV-248697r779657_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000199
Version
OL08-00-020210
Vuln IDs
  • V-248697
Rule IDs
  • SV-248697r779657_rule
Any password, no matter how complex, can eventually be cracked. Therefore, passwords need to be changed periodically. If OL 8 does not limit the lifetime of passwords and force users to change their passwords, there is the risk that OL 8 passwords could be compromised.
Checks: C-52131r779655_chk

Verify the maximum time period for existing passwords is restricted to 60 days with the following commands: $ sudo awk -F: '$5 &gt; 60 {print $1 " " $5}' /etc/shadow $ sudo awk -F: '$5 &lt;= 0 {print $1 " " $5}' /etc/shadow If any results are returned that are not associated with a system account, this is a finding.

Fix: F-52085r779656_fix

Configure non-compliant accounts to enforce a 60-day maximum password lifetime restriction. $ sudo chage -M 60 [user]

a
OL 8 must be configured in the password-auth file to prohibit password reuse for a minimum of five generations.
IA-5 - Low - CCI-000200 - V-248698 - SV-248698r902821_rule
RMF Control
IA-5
Severity
Low
CCI
CCI-000200
Version
OL08-00-020220
Vuln IDs
  • V-248698
Rule IDs
  • SV-248698r902821_rule
Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. If the information system or application allows the user to reuse their password consecutively when that password has exceeded its defined lifetime, the end result is a password that is not changed per policy requirements. OL 8 uses "pwhistory" consecutively as a mechanism to prohibit password reuse. This is set in both of the following: /etc/pam.d/password-auth /etc/pam.d/system-auth Note that manual changes to the listed files may be overwritten by the "authselect" program.
Checks: C-52132r902819_chk

Verify the operating system is configured in the password-auth file to prohibit password reuse for a minimum of five generations. Check for the value of the "remember" argument in "/etc/pam.d/password-auth" with the following command: $ sudo grep -i remember /etc/pam.d/password-auth password requisite pam_pwhistory.so use_authtok remember=5 retry=3 If the line containing "pam_pwhistory.so" does not have the "remember" module argument set, is commented out, or the value of the "remember" module argument is set to less than "5", this is a finding.

Fix: F-52086r902820_fix

Configure the operating system in the password-auth file to prohibit password reuse for a minimum of five generations. Add the following line in "/etc/pam.d/password-auth" (or modify the line to have the required value): password requisite pam_pwhistory.so use_authtok remember=5 retry=3

b
OL 8 passwords must have a minimum of 15 characters.
IA-5 - Medium - CCI-000205 - V-248699 - SV-248699r858645_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000205
Version
OL08-00-020230
Vuln IDs
  • V-248699
Rule IDs
  • SV-248699r858645_rule
Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password length is one factor of several that helps to determine strength and how long it takes to crack a password. Use of more characters in a password helps to increase exponentially the time and/or resources required to compromise the password. OL 8 uses "pwquality" as a mechanism to enforce password complexity. Configurations are set in the "etc/security/pwquality.conf" file. The "minlen", sometimes noted as minimum length, acts as a "score" of complexity based on the credit components of the "pwquality" module. By setting the credit components to a negative value, not only will those components be required, but they will not count toward the total "score" of "minlen". This will enable "minlen" to require a 15-character minimum.
Checks: C-52133r833233_chk

Verify the operating system enforces a minimum 15-character password length. The "minlen" option sets the minimum number of characters in a new password. Check for the value of the "minlen" option in "/etc/security/pwquality.conf" or "/etc/security/pwquality.conf.d/*.conf" files with the following command: $ sudo grep -r minlen /etc/security/pwquality.conf* /etc/security/pwquality.conf:minlen = 15 If the command does not return a "minlen" value of 15 or greater or is commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52087r858644_fix

Configure OL 8 to enforce a minimum 15-character password length. Add or update the following line in the "/etc/security/pwquality.conf" file or a configuration file in the "/etc/security/pwquality.conf.d/" directory: minlen = 15 Remove any configurations that conflict with the above value.

b
OL 8 passwords for new users must have a minimum of 15 characters.
IA-5 - Medium - CCI-000205 - V-248700 - SV-248700r779666_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000205
Version
OL08-00-020231
Vuln IDs
  • V-248700
Rule IDs
  • SV-248700r779666_rule
The shorter the password, the lower the number of possible combinations that need to be tested before the password is compromised. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password length is one factor of several that helps to determine strength and how long it takes to crack a password. Use of more characters in a password helps to increase exponentially the time and/or resources required to compromise the password. The DoD minimum password requirement is 15 characters.
Checks: C-52134r779664_chk

Verify that OL 8 enforces a minimum 15-character password length for new user accounts by running the following command: $ sudo grep -i pass_min_len /etc/login.defs PASS_MIN_LEN 15 If the "PASS_MIN_LEN" parameter value is less than "15" or is commented out, this is a finding.

Fix: F-52088r779665_fix

Configure operating system to enforce a minimum 15-character password length for new user accounts. Add or modify the following line in the "/etc/login.defs" file: PASS_MIN_LEN 15

b
OL 8 duplicate User IDs (UIDs) must not exist for interactive users.
AU-3 - Medium - CCI-000135 - V-248701 - SV-248701r779669_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000135
Version
OL08-00-020240
Vuln IDs
  • V-248701
Rule IDs
  • SV-248701r779669_rule
To ensure accountability and prevent unauthenticated access, interactive users must be identified and authenticated to prevent potential misuse and compromise of the system. Interactive users include organizational employees or individuals the organization deems to have equivalent status of employees (e.g., contractors). Interactive users (and processes acting on behalf of users) must be uniquely identified and authenticated to all accesses, except for the following: 1) Accesses explicitly identified and documented by the organization. Organizations document specific user actions that can be performed on the information system without identification or authentication; and 2) Accesses that occur through authorized use of group authenticators without individual authentication. Organizations may require unique identification of individuals in group accounts (e.g., shared privilege accounts) or for detailed accountability of individual activity. Satisfies: SRG-OS-000042-GPOS-00020, SRG-OS-000104-GPOS-00051, SRG-OS-000121-GPOS-00062
Checks: C-52135r779667_chk

Verify that OL 8 contains no duplicate UIDs for interactive users with the following command: $ sudo awk -F ":" 'list[$3]++{print $1, $3}' /etc/passwd If output is produced and the accounts listed are interactive user accounts, this is a finding.

Fix: F-52089r779668_fix

Edit the file "/etc/passwd" and provide each interactive user account that has a duplicate UID with a unique UID.

b
OL 8 must implement multifactor authentication for access to interactive accounts.
IA-2 - Medium - CCI-000765 - V-248702 - SV-248702r943098_rule
RMF Control
IA-2
Severity
Medium
CCI
CCI-000765
Version
OL08-00-020250
Vuln IDs
  • V-248702
Rule IDs
  • SV-248702r943098_rule
Using an authentication device, such as a Common Access Card (CAC) or token that is separate from the information system, ensures that even if the information system is compromised, that compromise will not affect credentials stored on the authentication device. Multifactor solutions that require devices separate from information systems gaining access include, for example, hardware tokens providing time-based or challenge-response authenticators and smart cards such as the U.S. Government Personal Identity Verification card and the DoD CAC. There are various methods of implementing multifactor authentication for OL 8. Some methods include a local system multifactor account mapping or joining the system to a domain and using an idM server or Microsoft Windows Active Directory server. Any of these methods will require that the client operating system handle the multifactor authentication correctly. Satisfies: SRG-OS-000105-GPOS-00052, SRG-OS-000106-GPOS-00053, SRG-OS-000107-GPOS-00054, SRG-OS-000108-GPOS-00055
Checks: C-52136r943096_chk

Verify OL 8 uses multifactor authentication for local access to accounts. Note: If the System Administrator demonstrates the use of an approved alternate multifactor authentication method, this requirement is not applicable. Check that the "pam_cert_auth" setting is set to "true" in the "/etc/sssd/sssd.conf" file. Check that the "try_cert_auth" or "require_cert_auth" options are configured in both "/etc/pam.d/system-auth" and "/etc/pam.d/smartcard-auth" files with the following command: $ sudo grep -ir cert_auth /etc/sssd/sssd.conf /etc/sssd/conf.d/*.conf /etc/pam.d/* /etc/sssd/sssd.conf:pam_cert_auth = True /etc/pam.d/smartcard-auth:auth sufficient pam_sss.so try_cert_auth /etc/pam.d/system-auth:auth [success=done authinfo_unavail=ignore ignore=ignore default=die] pam_sss.so try_cert_auth If "pam_cert_auth" is not set to "true" in "/etc/sssd/sssd.conf", this is a finding. If "pam_sss.so" is not set to "try_cert_auth" or "require_cert_auth" in both the "/etc/pam.d/smartcard-auth" and "/etc/pam.d/system-auth" files, this is a finding.

Fix: F-52090r943097_fix

Configure OL 8 to use multifactor authentication for local access to accounts. Add or update the "pam_cert_auth" setting in the "/etc/sssd/sssd.conf" file to match the following line: [pam] pam_cert_auth = True Add or update "pam_sss.so" with "try_cert_auth" or "require_cert_auth" in the "/etc/pam.d/system-auth" and "/etc/pam.d/smartcard-auth" files based on the following examples: /etc/pam.d/smartcard-auth:auth sufficient pam_sss.so try_cert_auth /etc/pam.d/system-auth:auth [success=done authinfo_unavail=ignore ignore=ignore default=die] pam_sss.so try_cert_auth The "sssd" service must be restarted for the changes to take effect. To restart the "sssd" service, run the following command: $ sudo systemctl restart sssd.service

b
The OL 8 system-auth file must disable access to the system for account identifiers (individuals, groups, roles, and devices) with 35 days of inactivity.
IA-4 - Medium - CCI-000795 - V-248703 - SV-248703r779675_rule
RMF Control
IA-4
Severity
Medium
CCI
CCI-000795
Version
OL08-00-020260
Vuln IDs
  • V-248703
Rule IDs
  • SV-248703r779675_rule
Inactive identifiers pose a risk to systems and applications because attackers may exploit an inactive identifier and potentially obtain undetected access to the system. Owners of inactive accounts will not notice if unauthorized access to their user account has been obtained. OL 8 needs to track periods of inactivity and disable application identifiers after 35 days of inactivity.
Checks: C-52137r779673_chk

Verify the account identifiers (individuals, groups, roles, and devices) are disabled after 35 days of inactivity by checking the account inactivity value with the following command: $ sudo grep 'inactive\|pam_unix' /etc/pam.d/system-auth | grep -w auth auth required pam_lastlog.so inactive=35 auth sufficient pam_unix.so If the pam_lastlog.so module is listed below the pam_unix.so module in the "system-auth" file, this is a finding. If the value of "inactive" is set to zero, a negative number, or is greater than 35, this is a finding. If the line is commented out or missing, ask the administrator to indicate how the system disables access for account identifiers. If there is no evidence that the system is disabling access for account identifiers after 35 days of inactivity, this is a finding.

Fix: F-52091r779674_fix

Configure OL 8 to disable access to the system for account identifiers with 35 days of inactivity. Add/Modify the following line to "/etc/pam.d/system-auth" above the "pam_unix.so" statement: auth required pam_lastlog.so inactive=35 Note: The DoD recommendation is 35 days, but a lower value is acceptable.

b
The OL 8 password-auth file must disable access to the system for account identifiers (individuals, groups, roles, and devices) with 35 days of inactivity.
IA-4 - Medium - CCI-000795 - V-248704 - SV-248704r779678_rule
RMF Control
IA-4
Severity
Medium
CCI
CCI-000795
Version
OL08-00-020261
Vuln IDs
  • V-248704
Rule IDs
  • SV-248704r779678_rule
Inactive identifiers pose a risk to systems and applications because attackers may exploit an inactive identifier and potentially obtain undetected access to the system. Owners of inactive accounts will not notice if unauthorized access to their user account has been obtained. OL 8 needs to track periods of inactivity and disable application identifiers after 35 days of inactivity.
Checks: C-52138r779676_chk

Verify the account identifiers (individuals, groups, roles, and devices) are disabled after 35 days of inactivity by checking the account inactivity value with the following command: $ sudo grep 'inactive\|pam_unix' /etc/pam.d/password-auth | grep -w auth auth required pam_lastlog.so inactive=35 auth sufficient pam_unix.so If the pam_lastlog.so module is listed below the pam_unix.so module in the "password-auth" file, this is a finding. If the value of "inactive" is set to zero, a negative number, or is greater than 35, this is a finding. If the line is commented out or missing, ask the administrator to indicate how the system disables access for account identifiers. If there is no evidence that the system is disabling access for account identifiers after 35 days of inactivity, this is a finding.

Fix: F-52092r779677_fix

Configure OL 8 to disable access to the system for account identifiers with 35 days of inactivity. Add/Modify the following line to "/etc/pam.d/password-auth" above the "pam_unix.so" statement: auth required pam_lastlog.so inactive=35 Note: The DoD recommendation is 35 days, but a lower value is acceptable.

b
The OL 8 lastlog command must have a mode of "0750" or less permissive.
SI-11 - Medium - CCI-001314 - V-248705 - SV-248705r779681_rule
RMF Control
SI-11
Severity
Medium
CCI
CCI-001314
Version
OL08-00-020262
Vuln IDs
  • V-248705
Rule IDs
  • SV-248705r779681_rule
Unauthorized disclosure of the contents of the /var/log/lastlog file can reveal system data to attackers, thus compromising its confidentiality.
Checks: C-52139r779679_chk

Verify the "lastlog" command has a mode of "0750" or less permissive with the following command: $ sudo stat -c "%a %n" /usr/bin/lastlog 750 /usr/bin/lastlog If the "lastlog" command has a mode more permissive than "0750", this is a finding.

Fix: F-52093r779680_fix

Configure the mode of the "lastlog" command for OL 8 to "0750" with the following command: $ sudo chmod 0750 /usr/bin/lastlog

b
The OL 8 lastlog command must be owned by root.
SI-11 - Medium - CCI-001314 - V-248706 - SV-248706r779684_rule
RMF Control
SI-11
Severity
Medium
CCI
CCI-001314
Version
OL08-00-020263
Vuln IDs
  • V-248706
Rule IDs
  • SV-248706r779684_rule
Unauthorized disclosure of the contents of the /var/log/lastlog file can reveal system data to attackers, thus compromising its confidentiality.
Checks: C-52140r779682_chk

Verify the "lastlog" command is owned by root with the following command: $ sudo ls -l /usr/bin/lastlog -rwxr-x---. 1 root root 21200 Nov 4 22:51 /usr/bin/lastlog If the "lastlog" command is not owned by root, this is a finding.

Fix: F-52094r779683_fix

Configure the "lastlog" command for OL 8 to be owned by root with the following command: $ sudo chown root /usr/bin/lastlog

b
The OL 8 lastlog command must be group-owned by root.
SI-11 - Medium - CCI-001314 - V-248707 - SV-248707r779687_rule
RMF Control
SI-11
Severity
Medium
CCI
CCI-001314
Version
OL08-00-020264
Vuln IDs
  • V-248707
Rule IDs
  • SV-248707r779687_rule
Unauthorized disclosure of the contents of the /var/log/lastlog file can reveal system data to attackers, thus compromising its confidentiality.
Checks: C-52141r779685_chk

Verify the "lastlog" command is group-owned by root with the following command: $ sudo ls -l /usr/bin/lastlog -rwxr-x---. 1 root root 21200 Nov 4 22:51 /usr/bin/lastlog If the "lastlog" command is not group-owned by root, this is a finding.

Fix: F-52095r779686_fix

Configure the "lastlog" command for OL 8 to be group-owned by root with the following command: $ sudo chgrp root /usr/bin/lastlog

b
OL 8 must automatically expire temporary accounts within 72 hours.
AC-2 - Medium - CCI-001682 - V-248708 - SV-248708r902791_rule
RMF Control
AC-2
Severity
Medium
CCI
CCI-001682
Version
OL08-00-020270
Vuln IDs
  • V-248708
Rule IDs
  • SV-248708r902791_rule
Temporary accounts are privileged or nonprivileged accounts that are established during pressing circumstances, such as new software or hardware configuration or an incident response, where the need for prompt account activation requires bypassing normal account authorization procedures. If any inactive temporary accounts are left enabled on the system and are not either manually removed or automatically expired within 72 hours, the security posture of the system will be degraded and exposed to expoitation by unauthorized users or insider threat actors. Temporary accounts are different from emergency accounts. Emergency accounts, also known as "last resort" or "break glass" accounts, are local logon accounts enabled on the system for emergency use by authorized system administrators to manage a system when standard logon methods are failing or not available. Emergency accounts are not subject to manual removal or scheduled expiration requirements. The automatic expiration of temporary accounts may be extended as needed by the circumstances but it must not be extended indefinitely. A documented permanent account should be established for privileged users who need long-term maintenance accounts.
Checks: C-52142r902789_chk

Verify temporary accounts have been provisioned with an expiration date of 72 hours. For every existing temporary account, run the following command to obtain its account expiration information: $ sudo chage -l &lt;temporary_account_name&gt; | grep -i "account expires" Verify each of these accounts has an expiration date set within 72 hours. If any temporary accounts have no expiration date set or do not expire within 72 hours, this is a finding.

Fix: F-52096r902790_fix

Configure the operating system to expire temporary accounts after 72 hours with the following command: $ sudo chage -E $(date -d +3days +%Y-%m-%d) <temporary_account_name>

a
All OL 8 passwords must contain at least one special character.
IA-5 - Low - CCI-001619 - V-248709 - SV-248709r858647_rule
RMF Control
IA-5
Severity
Low
CCI
CCI-001619
Version
OL08-00-020280
Vuln IDs
  • V-248709
Rule IDs
  • SV-248709r858647_rule
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. OL 8 uses "pwquality" as a mechanism to enforce password complexity. Note that to require special characters without degrading the "minlen" value, the credit value must be expressed as a negative number in "/etc/security/pwquality.conf".
Checks: C-52143r833235_chk

Verify the value for "ocredit" in "/etc/security/pwquality.conf" or "/etc/security/pwquality.conf.d/*.conf" files with the following command: $ sudo grep -r ocredit /etc/security/pwquality.conf* /etc/security/pwquality.conf:ocredit = -1 If the value of "ocredit" is a positive number or is commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52097r858646_fix

Configure OL 8 to enforce password complexity by requiring that at least one special character be used by setting the "ocredit" option. Add or update the following line in the "/etc/security/pwquality.conf" file or a configuration file in the "/etc/security/pwquality.conf.d/" directory: ocredit = -1 Remove any configurations that conflict with the above value.

b
OL 8 must prohibit the use of cached authentications after one day.
IA-5 - Medium - CCI-002007 - V-248710 - SV-248710r943101_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-002007
Version
OL08-00-020290
Vuln IDs
  • V-248710
Rule IDs
  • SV-248710r943101_rule
If cached authentication information is out of date, the validity of the authentication information may be questionable. OL 8 includes multiple options for configuring authentication, but this requirement will focus on the System Security Services Daemon (SSSD). By default, SSSD does not cache credentials.
Checks: C-52144r943099_chk

Verify that the SSSD prohibits the use of cached authentications after one day. Note: If smart card authentication is not being used on the system, this item is not applicable. Check that SSSD allows cached authentications with the following command: $ sudo grep -ir cache_credentials /etc/sssd/sssd.conf /etc/sssd/conf.d/*.conf cache_credentials = true If "cache_credentials" is set to "false" or is missing from the configuration file, this is not a finding and no further checks are required. If "cache_credentials" is set to "true", check that SSSD prohibits the use of cached authentications after one day with the following command: $ sudo grep -ir offline_credentials_expiration /etc/sssd/sssd.conf /etc/sssd/conf.d/*.conf offline_credentials_expiration = 1 If "offline_credentials_expiration" is not set to a value of "1", this is a finding.

Fix: F-52098r943100_fix

Configure the SSSD to prohibit the use of cached authentications after one day. Add or change the following line in "/etc/sssd/sssd.conf" just below the line "[pam]". offline_credentials_expiration = 1

b
OL 8 must prevent the use of dictionary words for passwords.
CM-6 - Medium - CCI-000366 - V-248711 - SV-248711r858649_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-020300
Vuln IDs
  • V-248711
Rule IDs
  • SV-248711r858649_rule
If OL 8 allows the user to select passwords based on dictionary words, this increases the chances of password compromise by increasing the opportunity for successful guesses and brute-force attacks.
Checks: C-52145r833237_chk

Verify OL 8 prevents the use of dictionary words for passwords. Determine if the field "dictcheck" is set in the "/etc/security/pwquality.conf" or "/etc/security/pwquality.conf.d/*.conf" files with the following command: $ sudo grep -r dictcheck /etc/security/pwquality.conf* /etc/security/pwquality.conf:dictcheck=1 If the "dictcheck" parameter is not set to "1" or is commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52099r858648_fix

Configure OL 8 to prevent the use of dictionary words for passwords. Add or update the following line in the "/etc/security/pwquality.conf" file or a configuration file in the "/etc/security/pwquality.conf.d/" directory: dictcheck=1 Remove any configurations that conflict with the above value.

b
OL 8 must enforce a delay of at least four seconds between logon prompts following a failed logon attempt.
CM-6 - Medium - CCI-000366 - V-248712 - SV-248712r779702_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-020310
Vuln IDs
  • V-248712
Rule IDs
  • SV-248712r779702_rule
Configuring the operating system to implement organization-wide security implementation guides and security checklists verifies compliance with federal standards and establishes a common security baseline across the DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example, registry settings; account, file, and directory permission settings; and settings for functions, ports, protocols, services, and remote connections.
Checks: C-52146r779700_chk

Verify the operating system enforces a delay of at least four seconds between console logon prompts following a failed logon attempt with the following command: $ sudo grep -i fail_delay /etc/login.defs FAIL_DELAY 4 If the value of "FAIL_DELAY" is not set to "4" or greater or the line is commented out, this is a finding.

Fix: F-52100r779701_fix

Configure OL 8 to enforce a delay of at least four seconds between logon prompts following a failed console logon attempt. Modify the "/etc/login.defs" file to set the "FAIL_DELAY" parameter to "4" or greater: FAIL_DELAY 4

b
OL 8 must not have unnecessary accounts.
CM-6 - Medium - CCI-000366 - V-248713 - SV-248713r779705_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-020320
Vuln IDs
  • V-248713
Rule IDs
  • SV-248713r779705_rule
Accounts providing no operational purpose provide additional opportunities for system compromise. Unnecessary accounts include user accounts for individuals not requiring access to the system and application accounts for applications not installed on the system.
Checks: C-52147r779703_chk

Verify all accounts on the system are assigned to an active system, application, or user account. Obtain the list of authorized system accounts from the Information System Security Officer (ISSO). Check the system accounts on the system with the following command: $ sudo more /etc/passwd root:x:0:0:root:/root:/bin/bash bin:x:1:1:bin:/bin:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin sync:x:5:0:sync:/sbin:/bin/sync shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown halt:x:7:0:halt:/sbin:/sbin/halt games:x:12:100:games:/usr/games:/sbin/nologin gopher:x:13:30:gopher:/var/gopher:/sbin/nologin Accounts such as "games" and "gopher" are not authorized accounts as they do not support authorized system functions. If the accounts on the system do not match the provided documentation, or accounts that do not support an authorized system function are present, this is a finding.

Fix: F-52101r779704_fix

Configure the system so all accounts on the system are assigned to an active system, application, or user account. Remove accounts that do not support approved system activities or that allow for a normal user to perform administrative-level actions. Document all authorized accounts on the system.

c
OL 8 must not allow accounts configured with blank or null passwords.
CM-6 - High - CCI-000366 - V-248714 - SV-248714r858582_rule
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
OL08-00-020330
Vuln IDs
  • V-248714
Rule IDs
  • SV-248714r858582_rule
If an account has an empty password, anyone could log on and run commands with the privileges of that account. Accounts with empty passwords should never be used in operational environments.
Checks: C-52148r858581_chk

To verify that null passwords cannot be used, run the following command: $ sudo grep -ir permitemptypasswords /etc/ssh/sshd_config* PermitEmptyPasswords no If "PermitEmptyPasswords" is set to "yes", this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52102r779707_fix

Edit the following line in "etc/ssh/sshd_config" to prevent logons with empty passwords. PermitEmptyPasswords no The SSH daemon must be restarted for the changes to take effect. To restart the SSH daemon, run the following command: $ sudo systemctl restart sshd.service

c
OL 8 must not allow blank or null passwords in the system-auth file.
CM-6 - High - CCI-000366 - V-248715 - SV-248715r779711_rule
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
OL08-00-020331
Vuln IDs
  • V-248715
Rule IDs
  • SV-248715r779711_rule
If an account has an empty password, anyone could log on and run commands with the privileges of that account. Accounts with empty passwords should never be used in operational environments.
Checks: C-52149r779709_chk

To verify that null passwords cannot be used, run the following command: $ sudo grep -i nullok /etc/pam.d/system-auth If output is produced, this is a finding.

Fix: F-52103r779710_fix

Remove any instances of the "nullok" option in the "/etc/pam.d/system-auth" file to prevent logons with empty passwords. Note: Manual changes to the listed file may be overwritten by the "authselect" program.

c
OL 8 must not allow blank or null passwords in the password-auth file.
CM-6 - High - CCI-000366 - V-248716 - SV-248716r779714_rule
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
OL08-00-020332
Vuln IDs
  • V-248716
Rule IDs
  • SV-248716r779714_rule
If an account has an empty password, anyone could log on and run commands with the privileges of that account. Accounts with empty passwords should never be used in operational environments.
Checks: C-52150r779712_chk

To verify that null passwords cannot be used, run the following command: $ sudo grep -i nullok /etc/pam.d/password-auth If output is produced, this is a finding.

Fix: F-52104r779713_fix

Remove any instances of the "nullok" option in the "/etc/pam.d/password-auth" file to prevent logons with empty passwords. Note: Manual changes to the listed file may be overwritten by the "authselect" program.

a
OL 8 must display the date and time of the last successful account logon upon logon.
AC-9 - Low - CCI-000052 - V-248717 - SV-248717r858591_rule
RMF Control
AC-9
Severity
Low
CCI
CCI-000052
Version
OL08-00-020340
Vuln IDs
  • V-248717
Rule IDs
  • SV-248717r858591_rule
Providing users with feedback on when account accesses last occurred facilitates user recognition and reporting of unauthorized account use.
Checks: C-52151r779715_chk

Verify users are provided with feedback on when account accesses last occurred with the following command: $ sudo grep pam_lastlog /etc/pam.d/postlogin session required pam_lastlog.so showfailed If "pam_lastlog" is missing from the "/etc/pam.d/postlogin" file or the silent option is present, this is a finding.

Fix: F-52105r779716_fix

Configure OL 8 to provide users with feedback on when account accesses last occurred by setting the required configuration options in "/etc/pam.d/postlogin". Add the following line to the top of "/etc/pam.d/postlogin": session required pam_lastlog.so showfailed

b
OL 8 must display the date and time of the last successful account logon upon an SSH logon.
AC-9 - Medium - CCI-000052 - V-248718 - SV-248718r858584_rule
RMF Control
AC-9
Severity
Medium
CCI
CCI-000052
Version
OL08-00-020350
Vuln IDs
  • V-248718
Rule IDs
  • SV-248718r858584_rule
Providing users with feedback on when account accesses via SSH last occurred facilitates user recognition and reporting of unauthorized account use.
Checks: C-52152r858583_chk

Verify SSH provides users with feedback on when account accesses last occurred with the following command: $ sudo grep -ir printlastlog /etc/ssh/sshd_config* PrintLastLog yes If the "PrintLastLog" keyword is set to "no", is missing, or is commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52106r779719_fix

Configure SSH to provide users with feedback on when account accesses last occurred by setting the required configuration options in "/etc/pam.d/sshd" or in the "sshd_config" file used by the system ("/etc/ssh/sshd_config" will be used in the example). Note that this file may be named differently or be in a different location if using a version of SSH that is provided by a third-party vendor. Modify the "PrintLastLog" line in "/etc/ssh/sshd_config" to match the following: PrintLastLog yes The SSH service must be restarted for changes to "sshd_config" to take effect.

b
OL 8 default permissions must be defined in such a way that all authenticated users can read and modify only their own files.
CM-6 - Medium - CCI-000366 - V-248719 - SV-248719r779723_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-020351
Vuln IDs
  • V-248719
Rule IDs
  • SV-248719r779723_rule
Setting the most restrictive default permissions ensures that when new accounts are created, they do not have unnecessary access.
Checks: C-52153r779721_chk

Verify OL 8 defines default permissions for all authenticated users in such a way that the user can read and modify only their own files with the following command: $ sudo grep -i "umask" /etc/login.defs UMASK 077 If the "UMASK" variable is set to "000", this is a finding with the severity raised to a CAT I. If the value of "UMASK" is not set to "077", "UMASK" is commented out, or "UMASK" is missing completely, this is a finding.

Fix: F-52107r779722_fix

Configure OL 8 to define the default permissions for all authenticated users in such a way that the user can read and modify only their own files. Edit the "UMASK" parameter in the "/etc/login.defs" file to match the example below: UMASK 077

b
OL 8 must set the umask value to 077 for all local interactive user accounts.
CM-6 - Medium - CCI-000366 - V-248720 - SV-248720r858597_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-020352
Vuln IDs
  • V-248720
Rule IDs
  • SV-248720r858597_rule
The umask controls the default access mode assigned to newly created files. A umask of 077 limits new files to mode 600 or less permissive. Although umask can be represented as a four-digit number, the first digit representing special access modes is typically ignored or required to be "0". This requirement applies to the globally configured system defaults and the local interactive user defaults for each account on the system.
Checks: C-52154r858596_chk

Verify that the default umask for all local interactive users is "077". Identify the locations of all local interactive user home directories by looking at the "/etc/passwd" file. Check all local interactive user initialization files for interactive users with the following command: Note: The example is for a system that is configured to create users home directories in the "/home" directory. $ sudo grep -ir ^umask /home | grep -v '.bash_history' If any local interactive user initialization files are found to have a umask statement that has a value less restrictive than "077", this is a finding.

Fix: F-52108r779725_fix

Remove the umask statement from all local interactive user's initialization files. If the account is for an application, the requirement for a umask less restrictive than "077" can be documented with the Information System Security Officer, but the user agreement for access to the account must specify that the local interactive user must log on to their account first and then switch the user to the application account with the correct option to gain the account's environment variables.

b
OL 8 must define default permissions for logon and non-logon shells.
CM-6 - Medium - CCI-000366 - V-248721 - SV-248721r818666_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-020353
Vuln IDs
  • V-248721
Rule IDs
  • SV-248721r818666_rule
The umask controls the default access mode assigned to newly created files. A umask of 077 limits new files to mode 600 or less permissive. Although umask can be represented as a four-digit number, the first digit representing special access modes is typically ignored or required to be "0". This requirement applies to the globally configured system defaults and the local interactive user defaults for each account on the system.
Checks: C-52155r818664_chk

Verify that the umask default for installed shells is "077". Check for the value of the "UMASK" parameter in the "/etc/bashrc", "/etc/csh.cshrc", and "/etc/profile" files with the following command: Note: If the value of the "UMASK" parameter is set to "000" in the "/etc/bashrc", "/etc/csh.cshrc", or the "/etc/profile" files, the Severity is raised to a CAT I. $ sudo grep -i umask /etc/bashrc /etc/csh.cshrc /etc/profile /etc/bashrc: umask 077 /etc/bashrc: umask 077 /etc/csh.cshrc: umask 077 /etc/csh.cshrc: umask 077 /etc/profile: umask 077 /etc/profile: umask 077 If the value for the "UMASK" parameter is not "077", or the "UMASK" parameter is missing or is commented out, this is a finding.

Fix: F-52109r818665_fix

Configure the operating system to define default permissions for all authenticated users in such a way that the user can only read and modify their own files. Add or edit the lines for the "UMASK" parameter in the "/etc/bashrc", "etc/csh.cshrc", and "/etc/profile" files to "077": UMASK 077

b
The OL 8 audit system must be configured to audit the execution of privileged functions and prevent all software from executing at higher privilege levels than users executing the software.
AC-6 - Medium - CCI-002233 - V-248722 - SV-248722r853794_rule
RMF Control
AC-6
Severity
Medium
CCI
CCI-002233
Version
OL08-00-030000
Vuln IDs
  • V-248722
Rule IDs
  • SV-248722r853794_rule
Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised information system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider threats and the advanced persistent threat. Satisfies: SRG-OS-000326-GPOS-00126, SRG-OS-000327-GPOS-00127
Checks: C-52156r779730_chk

Verify OL 8 audits the execution of privileged functions. Check if OL 8 is configured to audit the execution of the "execve" system call, by running the following command: $ sudo grep execve /etc/audit/audit.rules -a always,exit -F arch=b32 -S execve -C uid!=euid -F key=execpriv -a always,exit -F arch=b64 -S execve -C uid!=euid -F key=execpriv -a always,exit -F arch=b32 -S execve -C gid!=egid -F key=execpriv -a always,exit -F arch=b64 -S execve -C gid!=egid -F key=execpriv If the command does not return all lines or the lines are commented out, this is a finding.

Fix: F-52110r779731_fix

Configure OL 8 to audit the execution of the "execve" system call. Add or update the following file system rules to "/etc/audit/rules.d/audit.rules": -a always,exit -F arch=b32 -S execve -C uid!=euid -F key=execpriv -a always,exit -F arch=b64 -S execve -C uid!=euid -F key=execpriv -a always,exit -F arch=b32 -S execve -C gid!=egid -F key=execpriv -a always,exit -F arch=b64 -S execve -C gid!=egid -F key=execpriv The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
Cron logging must be implemented in OL 8.
CM-6 - Medium - CCI-000366 - V-248723 - SV-248723r779735_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-030010
Vuln IDs
  • V-248723
Rule IDs
  • SV-248723r779735_rule
Cron logging can be used to trace the successful or unsuccessful execution of cron jobs. It can also be used to spot intrusions into the use of the cron facility by unauthorized and malicious users.
Checks: C-52157r779733_chk

Verify that "rsyslog" is configured to log cron events with the following command: Note: If another logging package is used, substitute the utility configuration file for "/etc/rsyslog.conf" or "/etc/rsyslog.d/*.conf" files. $ sudo grep cron /etc/rsyslog.conf /etc/rsyslog.d/*.conf cron.* /var/log/cron If the command does not return a response, check for cron logging all facilities by inspecting the "/etc/rsyslog.conf" or "/etc/rsyslog.d/*.conf" files. Look for the following entry: *.* /var/log/messages If "rsyslog" is not logging messages for the cron facility or all facilities, this is a finding.

Fix: F-52111r779734_fix

Configure "rsyslog" to log all cron messages by adding or updating the following line to "/etc/rsyslog.conf" or a configuration file in the "/etc/rsyslog.d/" directory: cron.* /var/log/cron The rsyslog daemon must be restarted for the changes to take effect: $ sudo systemctl restart rsyslog.service

b
The OL 8 System Administrator (SA) and Information System Security Officer (ISSO) (at a minimum) must be alerted of an audit processing failure event.
AU-5 - Medium - CCI-000139 - V-248724 - SV-248724r779738_rule
RMF Control
AU-5
Severity
Medium
CCI
CCI-000139
Version
OL08-00-030020
Vuln IDs
  • V-248724
Rule IDs
  • SV-248724r779738_rule
It is critical for the appropriate personnel to be aware if a system is at risk of failing to process audit logs as required. Without this notification, the security personnel may be unaware of an impending failure of the audit capability, and system operation may be adversely affected. Audit processing failures include software/hardware errors, failures in the audit capturing mechanisms, and audit storage capacity being reached or exceeded. This requirement applies to each audit data storage repository (i.e., distinct information system component where audit records are stored), the centralized audit storage capacity of organizations (i.e., all audit data storage repositories combined), or both.
Checks: C-52158r779736_chk

Verify that the SA and ISSO (at a minimum) are notified in the event of an audit processing failure with the following command: $ sudo grep action_mail_acct /etc/audit/auditd.conf action_mail_acct = root If the value of the "action_mail_acct" keyword is not set to "root" and/or other accounts for security personnel, the "action_mail_acct" keyword is missing, or the retuned line is commented out, ask the SA to indicate how they and the ISSO are notified of an audit process failure. If there is no evidence of the proper personnel being notified of an audit processing failure, this is a finding.

Fix: F-52112r779737_fix

Configure the "auditd" service to notify the SA and ISSO in the event of an audit processing failure. Edit the following line in "/etc/audit/auditd.conf" to ensure that administrators are notified via email for those situations: action_mail_acct = root

b
The OL 8 Information System Security Officer (ISSO) and System Administrator (SA) (at a minimum) must have mail aliases to be notified of an audit processing failure.
AU-5 - Medium - CCI-000139 - V-248725 - SV-248725r779741_rule
RMF Control
AU-5
Severity
Medium
CCI
CCI-000139
Version
OL08-00-030030
Vuln IDs
  • V-248725
Rule IDs
  • SV-248725r779741_rule
It is critical for the appropriate personnel to be aware if a system is at risk of failing to process audit logs as required. Without this notification, the security personnel may be unaware of an impending failure of the audit capability, and system operation may be adversely affected. Audit processing failures include software/hardware errors, failures in the audit capturing mechanisms, and audit storage capacity being reached or exceeded. This requirement applies to each audit data storage repository (i.e., distinct information system component where audit records are stored), the centralized audit storage capacity of organizations (i.e., all audit data storage repositories combined), or both.
Checks: C-52159r779739_chk

Verify the administrators are notified in the event of an audit processing failure. Check that the "/etc/aliases" file has a defined value for "root". $ sudo grep "postmaster:\s*root$" /etc/aliases postmaster: root If the command does not return a line or the line is commented out, this is a finding.

Fix: F-52113r779740_fix

Configure OL 8 to notify administrators in the event of an audit processing failure. Add/update the following line in "/etc/aliases": postmaster: root

b
The OL 8 System must take appropriate action when an audit processing failure occurs.
AU-5 - Medium - CCI-000140 - V-248726 - SV-248726r779744_rule
RMF Control
AU-5
Severity
Medium
CCI
CCI-000140
Version
OL08-00-030040
Vuln IDs
  • V-248726
Rule IDs
  • SV-248726r779744_rule
It is critical for the appropriate personnel to be aware if a system is at risk of failing to process audit logs as required. Without this notification, the security personnel may be unaware of an impending failure of the audit capability, and system operation may be adversely affected. Audit processing failures include software/hardware errors, failures in the audit capturing mechanisms, and audit storage capacity being reached or exceeded. This requirement applies to each audit data storage repository (i.e., distinct information system component where audit records are stored), the centralized audit storage capacity of organizations (i.e., all audit data storage repositories combined), or both.
Checks: C-52160r779742_chk

Verify OL 8 takes the appropriate action when an audit processing failure occurs with the following command: $ sudo grep disk_error_action /etc/audit/auditd.conf disk_error_action = HALT If the value of the "disk_error_action" option is not "SYSLOG", "SINGLE", or "HALT", or the line is commented out, this is a finding.

Fix: F-52114r779743_fix

Configure OL 8 to shut down by default upon audit failure (unless availability is an overriding concern). Add or update the following line ("disk_error_action" can be set to "SYSLOG" or "SINGLE" depending on configuration) in the "/etc/audit/auditd.conf" file: disk_error_action = HALT If availability has been determined to be more important, and this decision is documented with the ISSO, configure OL 8 to notify system administration staff and ISSO staff in the event of an audit processing failure by setting the "disk_error_action" to "SYSLOG".

b
The OL 8 audit system must take appropriate action when the audit storage volume is full.
AU-5 - Medium - CCI-000140 - V-248728 - SV-248728r779750_rule
RMF Control
AU-5
Severity
Medium
CCI
CCI-000140
Version
OL08-00-030060
Vuln IDs
  • V-248728
Rule IDs
  • SV-248728r779750_rule
It is critical that when OL 8 is at risk of failing to process audit logs as required, it takes action to mitigate the failure. Audit processing failures include software/hardware errors; failures in the audit capturing mechanisms; and audit storage capacity being reached or exceeded. Responses to audit failure depend on the nature of the failure mode. When availability is an overriding concern, other approved actions in response to an audit failure are as follows: 1) If the failure was caused by the lack of audit record storage capacity, OL 8 must continue generating audit records if possible (automatically restarting the audit service if necessary) and overwriting the oldest audit records in a first-in-first-out manner. 2) If audit records are sent to a centralized collection server and communication with this server is lost or the server fails, OL 8 must queue audit records locally until communication is restored or until the audit records are retrieved manually. Upon restoration of the connection to the centralized collection server, action should be taken to synchronize the local audit data with the collection server.
Checks: C-52162r779748_chk

Verify OL 8 takes the appropriate action when the audit storage volume is full with the following command: $ sudo grep disk_full_action /etc/audit/auditd.conf disk_full_action = HALT If the value of the "disk_full_action" option is not "SYSLOG", "SINGLE", or "HALT", or the line is commented out, this is a finding.

Fix: F-52116r779749_fix

Configure OL 8 to shut down by default upon audit failure (unless availability is an overriding concern). Add or update the following line ("disk_full_action" can be set to "SYSLOG" or "SINGLE" depending on configuration) in the "/etc/audit/auditd.conf" file: disk_full_action = HALT If availability has been determined to be more important, and this decision is documented with the ISSO, configure OL 8 to notify system administration staff and ISSO staff in the event of an audit processing failure by setting the "disk_full_action" to "SYSLOG".

b
The OL 8 audit system must audit local events.
CM-6 - Medium - CCI-000366 - V-248729 - SV-248729r779753_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-030061
Vuln IDs
  • V-248729
Rule IDs
  • SV-248729r779753_rule
Without establishing what type of events occurred, the source of events, where events occurred, and the outcome of events, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. Audit record content that may be necessary to satisfy this requirement includes, for example, time stamps, source and destination addresses, user/process identifiers, event descriptions, success/fail indications, filenames involved, and access control or flow control rules invoked.
Checks: C-52163r779751_chk

Verify the OL 8 Audit Daemon is configured to include local events, with the following command: $ sudo grep local_events /etc/audit/auditd.conf local_events = yes If the value of the "local_events" option is not set to "yes", or the line is commented out, this is a finding.

Fix: F-52117r779752_fix

Configure OL 8 to audit local events on the system. Add or update the following line in "/etc/audit/auditd.conf" file: local_events = yes

b
OL 8 must label all offloaded audit logs before sending them to the central log server.
AU-4 - Medium - CCI-001851 - V-248730 - SV-248730r877390_rule
RMF Control
AU-4
Severity
Medium
CCI
CCI-001851
Version
OL08-00-030062
Vuln IDs
  • V-248730
Rule IDs
  • SV-248730r877390_rule
Without establishing what type of events occurred and their source, location, and outcome, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. Audit record content that may be necessary to satisfy this requirement includes, for example, time stamps, source and destination addresses, user/process identifiers, event descriptions, success/fail indications, filenames involved, and access control or flow control rules invoked. Enriched logging is needed to determine who, what, and when events occur on a system. Without this, determining root cause of an event will be much more difficult. When audit logs are not labeled before they are sent to a central log server, the audit data will not be able to be analyzed and tied back to the correct system.
Checks: C-52164r779754_chk

Verify the OL 8 audit daemon is configured to label all offloaded audit logs with the following command: $ sudo grep "name_format" /etc/audit/auditd.conf name_format = hostname If the "name_format" option is not "hostname", "fqd", or "numeric", or the line is commented out, this is a finding.

Fix: F-52118r779755_fix

Edit the "/etc/audit/auditd.conf" file and add or update the "name_format" option: name_format = hostname The audit daemon must be restarted for changes to take effect.

b
OL 8 must resolve audit information before writing to disk.
CM-6 - Medium - CCI-000366 - V-248731 - SV-248731r779759_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-030063
Vuln IDs
  • V-248731
Rule IDs
  • SV-248731r779759_rule
Without establishing what type of events occurred and their source, location, and outcome, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. Audit record content that may be necessary to satisfy this requirement includes, for example, time stamps, source and destination addresses, user/process identifiers, event descriptions, success/fail indications, filenames involved, and access control or flow control rules invoked. Enriched logging aids in making sense of who, what, and when events occur on a system. Without this, determining root cause of an event will be much more difficult.
Checks: C-52165r779757_chk

Verify the OL 8 audit daemon is configured to resolve audit information before writing to disk, with the following command: $ sudo grep "log_format" /etc/audit/auditd.conf log_format = ENRICHED If the "log_format" option is not "ENRICHED", or the line is commented out, this is a finding.

Fix: F-52119r779758_fix

Configure OL 8 to resolve audit information before writing to disk by adding the following line to the "/etc/audit/auditd.conf" file and add or update the "log_format" option: log_format = ENRICHED The audit daemon must be restarted for changes to take effect.

b
OL 8 audit logs must have a mode of "0600" or less permissive to prevent unauthorized read access.
AU-9 - Medium - CCI-000162 - V-248732 - SV-248732r779762_rule
RMF Control
AU-9
Severity
Medium
CCI
CCI-000162
Version
OL08-00-030070
Vuln IDs
  • V-248732
Rule IDs
  • SV-248732r779762_rule
Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality. Audit information includes all information (e.g., audit records, audit settings, audit reports) needed to successfully audit OL 8 activity. Satisfies: SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029
Checks: C-52166r779760_chk

Verify the audit logs have a mode of "0600" or less permissive. Determine where the audit logs are stored with the following command: $ sudo grep -iw log_file /etc/audit/auditd.conf log_file = /var/log/audit/audit.log Using the location of the audit log file, determine if the audit log has a mode of "0600" or less permissive with the following command: $ sudo stat -c "%a %n" /var/log/audit/audit.log 600 /var/log/audit/audit.log If the audit log has a mode more permissive than "0600", this is a finding.

Fix: F-52120r779761_fix

Configure the audit log to be protected from unauthorized read access by setting the correct permissive mode with the following command: $ sudo chmod 0600 [audit_log_file] Replace "[audit_log_file]" to the correct audit log path. By default, this location is "/var/log/audit/audit.log".

b
OL 8 audit logs must be owned by root to prevent unauthorized read access.
AU-9 - Medium - CCI-000162 - V-248733 - SV-248733r779765_rule
RMF Control
AU-9
Severity
Medium
CCI
CCI-000162
Version
OL08-00-030080
Vuln IDs
  • V-248733
Rule IDs
  • SV-248733r779765_rule
Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality. Audit information includes all information (e.g., audit records, audit settings, audit reports) needed to successfully audit OL 8 activity. Satisfies: SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029
Checks: C-52167r779763_chk

Verify the audit logs are owned by "root". Determine where the audit logs are stored with the following command: $ sudo grep -iw log_file /etc/audit/auditd.conf log_file = /var/log/audit/audit.log Using the location of the audit log file, determine if the audit log is owned by "root" using the following command: $ sudo ls -al /var/log/audit/audit.log rw------- 2 root root 23 Jun 11 11:56 /var/log/audit/audit.log If the audit log is not owned by "root", this is a finding.

Fix: F-52121r779764_fix

Configure the audit log to be protected from unauthorized read access by setting the correct owner as "root" with the following command: $ sudo chown root [audit_log_file] Replace "[audit_log_file]" to the correct audit log path. By default, this location is "/var/log/audit/audit.log".

b
OL 8 audit logs must be group-owned by root to prevent unauthorized read access.
AU-9 - Medium - CCI-000162 - V-248734 - SV-248734r779768_rule
RMF Control
AU-9
Severity
Medium
CCI
CCI-000162
Version
OL08-00-030090
Vuln IDs
  • V-248734
Rule IDs
  • SV-248734r779768_rule
Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality. Audit information includes all information (e.g., audit records, audit settings, audit reports) needed to successfully audit OL 8 activity. Satisfies: SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029
Checks: C-52168r779766_chk

Verify the audit logs are group-owned by "root". Determine where the audit logs are stored with the following command: $ sudo grep -iw log_file /etc/audit/auditd.conf log_file = /var/log/audit/audit.log Using the location of the audit log file, determine if the audit log is group-owned by "root" using the following command: $ sudo ls -al /var/log/audit/audit.log rw------- 2 root root 23 Jun 11 11:56 /var/log/audit/audit.log If the audit log is not group-owned by "root", this is a finding.

Fix: F-52122r779767_fix

Configure the audit log to be protected from unauthorized read access by setting the correct group-owner as "root" with the following command: $ sudo chgrp root [audit_log_file] Replace "[audit_log_file]" to the correct audit log path. By default, this location is "/var/log/audit/audit.log".

b
The OL 8 audit log directory must be owned by root to prevent unauthorized read access.
AU-9 - Medium - CCI-000162 - V-248735 - SV-248735r779771_rule
RMF Control
AU-9
Severity
Medium
CCI
CCI-000162
Version
OL08-00-030100
Vuln IDs
  • V-248735
Rule IDs
  • SV-248735r779771_rule
Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality. Audit information includes all information (e.g., audit records, audit settings, audit reports) needed to successfully audit OL 8 activity. Satisfies: SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029
Checks: C-52169r779769_chk

Verify the audit log directory is owned by "root" to prevent unauthorized read access. Determine where the audit logs are stored with the following command: $ sudo grep -iw log_file /etc/audit/auditd.conf log_file = /var/log/audit/audit.log Determine the owner of the audit log directory by using the output of the above command (ex: "/var/log/audit/"). Run the following command with the correct audit log directory path: $ sudo ls -ld /var/log/audit drwx------ 2 root root 23 Jun 11 11:56 /var/log/audit If the audit log directory is not owned by "root", this is a finding.

Fix: F-52123r779770_fix

Configure the audit log to be protected from unauthorized read access by setting the correct owner as "root" with the following command: $ sudo chown root [audit_log_directory] Replace "[audit_log_directory]" with the correct audit log directory path. By default, this location is usually "/var/log/audit".

b
The OL 8 audit log directory must be group-owned by root to prevent unauthorized read access.
AU-9 - Medium - CCI-000162 - V-248736 - SV-248736r779774_rule
RMF Control
AU-9
Severity
Medium
CCI
CCI-000162
Version
OL08-00-030110
Vuln IDs
  • V-248736
Rule IDs
  • SV-248736r779774_rule
Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality. Audit information includes all information (e.g., audit records, audit settings, audit reports) needed to successfully audit OL 8 activity. Satisfies: SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029
Checks: C-52170r779772_chk

Verify the audit log directory is group-owned by "root" to prevent unauthorized read access. Determine where the audit logs are stored with the following command: $ sudo grep -iw log_file /etc/audit/auditd.conf log_file = /var/log/audit/audit.log Determine the group owner of the audit log directory by using the output of the above command (ex: "/var/log/audit/"). Run the following command with the correct audit log directory path: $ sudo ls -ld /var/log/audit drwx------ 2 root root 23 Jun 11 11:56 /var/log/audit If the audit log directory is not group-owned by "root", this is a finding.

Fix: F-52124r779773_fix

Configure the audit log to be protected from unauthorized read access by setting the correct group-owner as "root" with the following command: $ sudo chgrp root [audit_log_directory] Replace "[audit_log_directory]" with the correct audit log directory path. By default, this location is usually "/var/log/audit".

b
The OL 8 audit log directory must have a mode of 0700 or less permissive to prevent unauthorized read access.
AU-9 - Medium - CCI-000162 - V-248737 - SV-248737r779777_rule
RMF Control
AU-9
Severity
Medium
CCI
CCI-000162
Version
OL08-00-030120
Vuln IDs
  • V-248737
Rule IDs
  • SV-248737r779777_rule
Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality. Audit information includes all information (e.g., audit records, audit settings, audit reports) needed to successfully audit OL 8 system activity. Satisfies: SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029
Checks: C-52171r779775_chk

Verify the audit log directories have a mode of "0700" or less permissive by first determining where the audit logs are stored with the following command: $ sudo grep -iw log_file /etc/audit/auditd.conf log_file = /var/log/audit/audit.log Using the location of the audit log, determine the directory where the audit logs are stored (ex: "/var/log/audit"). Run the following command to determine the permissions for the audit log folder: $ sudo stat -c "%a %n" /var/log/audit 700 /var/log/audit If the audit log directory has a mode more permissive than "0700", this is a finding.

Fix: F-52125r779776_fix

Configure the audit log directory to be protected from unauthorized read access by setting the correct permissive mode with the following command: $ sudo chmod 0700 [audit_log_directory] Replace "[audit_log_directory]" to the correct audit log directory path. By default, this location is "/var/log/audit".

b
The OL 8 audit system must protect auditing rules from unauthorized change.
AU-9 - Medium - CCI-000162 - V-248738 - SV-248738r779780_rule
RMF Control
AU-9
Severity
Medium
CCI
CCI-000162
Version
OL08-00-030121
Vuln IDs
  • V-248738
Rule IDs
  • SV-248738r779780_rule
Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality. Audit information includes all information (e.g., audit records, audit settings, audit reports) needed to successfully audit OL 8 system activity. In immutable mode, unauthorized users cannot execute changes to the audit system to potentially hide malicious activity and then put the audit rules back. A system reboot would be noticeable and a system administrator could then investigate the unauthorized changes. Satisfies: SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029
Checks: C-52172r779778_chk

Verify the audit system prevents unauthorized changes with the following command: $ sudo grep "^\s*[^#]" /etc/audit/audit.rules | tail -1 -e 2 If the audit system is not set to be immutable by adding the "-e 2" option to the "/etc/audit/audit.rules", this is a finding.

Fix: F-52126r779779_fix

Configure the audit system to set the audit rules to be immutable by adding the following line to "/etc/audit/rules.d/audit.rules": -e 2 Note: Once set, the system must be rebooted for auditing to be changed. It is recommended to add this option as the last step in securing the system.

b
The OL 8 audit system must protect logon UIDs from unauthorized change.
AU-9 - Medium - CCI-000162 - V-248739 - SV-248739r779783_rule
RMF Control
AU-9
Severity
Medium
CCI
CCI-000162
Version
OL08-00-030122
Vuln IDs
  • V-248739
Rule IDs
  • SV-248739r779783_rule
Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality. Audit information includes all information (e.g., audit records, audit settings, audit reports) needed to successfully audit OL 8 system activity. In immutable mode, unauthorized users cannot execute changes to the audit system to potentially hide malicious activity and then put the audit rules back. A system reboot would be noticeable and a system administrator could then investigate the unauthorized changes. Satisfies: SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029
Checks: C-52173r779781_chk

Verify the audit system prevents unauthorized changes to logon UIDs with the following command: $ sudo grep -i immutable /etc/audit/audit.rules --loginuid-immutable If the login UIDs are not set to be immutable by adding the "--loginuid-immutable" option to the "/etc/audit/audit.rules", this is a finding.

Fix: F-52127r779782_fix

Configure the audit system to set the logon UIDs to be immutable by adding the following line to "/etc/audit/rules.d/audit.rules": --loginuid-immutable

b
OL 8 must generate audit records for all account creation events that affect "/etc/shadow".
AC-2 - Medium - CCI-000018 - V-248740 - SV-248740r853796_rule
RMF Control
AC-2
Severity
Medium
CCI
CCI-000018
Version
OL08-00-030130
Vuln IDs
  • V-248740
Rule IDs
  • SV-248740r853796_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000303-GPOS-00120, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000476-GPOS-00221
Checks: C-52174r779784_chk

Verify OL 8 generates audit records for all account creations, modifications, disabling, and termination events that affect "/etc/shadow". Check the auditing rules in "/etc/audit/audit.rules" with the following command: $ sudo grep /etc/shadow /etc/audit/audit.rules -w /etc/shadow -p wa -k identity If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52128r779785_fix

Configure OL 8 to generate audit records for all account creations events that affect "/etc/shadow". Add or update the following file system rule to "/etc/audit/rules.d/audit.rules": -w /etc/shadow -p wa -k identity The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for all account creation events that affect "/etc/security/opasswd".
AC-2 - Medium - CCI-000018 - V-248741 - SV-248741r853797_rule
RMF Control
AC-2
Severity
Medium
CCI
CCI-000018
Version
OL08-00-030140
Vuln IDs
  • V-248741
Rule IDs
  • SV-248741r853797_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000303-GPOS-00120, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000476-GPOS-00221
Checks: C-52175r779787_chk

Verify OL 8 generates audit records for all account creations, modifications, disabling, and termination events that affect "/etc/security/opasswd". Check the auditing rules in "/etc/audit/audit.rules" with the following command: $ sudo grep /etc/security/opasswd /etc/audit/audit.rules -w /etc/security/opasswd -p wa -k identity If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52129r779788_fix

Configure OL 8 to generate audit records for all account creations events that affect "/etc/security/opasswd". Add or update the following file system rule to "/etc/audit/rules.d/audit.rules": -w /etc/security/opasswd -p wa -k identity The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for all account creation events that affect "/etc/passwd".
AC-2 - Medium - CCI-000018 - V-248742 - SV-248742r853798_rule
RMF Control
AC-2
Severity
Medium
CCI
CCI-000018
Version
OL08-00-030150
Vuln IDs
  • V-248742
Rule IDs
  • SV-248742r853798_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000303-GPOS-00120, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000476-GPOS-00221
Checks: C-52176r779790_chk

Verify OL 8 generates audit records for all account creations, modifications, disabling, and termination events that affect "/etc/passwd". Check the auditing rules in "/etc/audit/audit.rules" with the following command: $ sudo grep /etc/passwd /etc/audit/audit.rules -w /etc/passwd -p wa -k identity If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52130r779791_fix

Configure OL 8 to generate audit records for all account creations events that affect "/etc/passwd". Add or update the following file system rule to "/etc/audit/rules.d/audit.rules": -w /etc/passwd -p wa -k identity The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for all account creation events that affect "/etc/gshadow".
AC-2 - Medium - CCI-000018 - V-248743 - SV-248743r853799_rule
RMF Control
AC-2
Severity
Medium
CCI
CCI-000018
Version
OL08-00-030160
Vuln IDs
  • V-248743
Rule IDs
  • SV-248743r853799_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000476-GPOS-00221
Checks: C-52177r779793_chk

Verify OL 8 generates audit records for all account creations, modifications, disabling, and termination events that affect "/etc/gshadow". Check the auditing rules in "/etc/audit/audit.rules" with the following command: $ sudo grep /etc/gshadow /etc/audit/audit.rules -w /etc/gshadow -p wa -k identity If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52131r779794_fix

Configure OL 8 to generate audit records for all account creations events that affect "/etc/gshadow". Add or update the following file system rule to "/etc/audit/rules.d/audit.rules": -w /etc/gshadow -p wa -k identity The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for all account creation events that affect "/etc/group".
AC-2 - Medium - CCI-000018 - V-248744 - SV-248744r853800_rule
RMF Control
AC-2
Severity
Medium
CCI
CCI-000018
Version
OL08-00-030170
Vuln IDs
  • V-248744
Rule IDs
  • SV-248744r853800_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000303-GPOS-00120, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000476-GPOS-00221
Checks: C-52178r779796_chk

Verify OL 8 generates audit records for all account creations events that affect "/etc/group". Check the auditing rules in "/etc/audit/audit.rules" with the following command: $ sudo grep /etc/group /etc/audit/audit.rules -w /etc/group -p wa -k identity If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52132r779797_fix

Configure OL 8 to generate audit records for all account creations events that affect "/etc/group". Add or update the following file system rule to "/etc/audit/rules.d/audit.rules": -w /etc/group -p wa -k identity The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for all account creations, modifications, disabling, and termination events that affect "/etc/sudoers".
AC-2 - Medium - CCI-000018 - V-248745 - SV-248745r853801_rule
RMF Control
AC-2
Severity
Medium
CCI
CCI-000018
Version
OL08-00-030171
Vuln IDs
  • V-248745
Rule IDs
  • SV-248745r853801_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000303-GPOS-00120, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000476-GPOS-00221
Checks: C-52179r779799_chk

Verify OL 8 generates audit records for all account creations, modifications, disabling, and termination events that affect "/etc/sudoers". Check the auditing rules in "/etc/audit/audit.rules" with the following command: $ sudo grep /etc/sudoers /etc/audit/audit.rules -w /etc/sudoers -p wa -k identity If the command does not return a line, or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52133r779800_fix

Configure OL 8 to generate audit records for all account creations, modifications, disabling, and termination events that affect "/etc/sudoers". Add or update the following file system rule to "/etc/audit/rules.d/audit.rules": -w /etc/sudoers -p wa -k identity The audit daemon must be restarted for the changes to take effect. $ sudo service auditd restart

b
OL 8 must generate audit records for all account creations, modifications, disabling, and termination events that affect "/etc/sudoers.d/".
AC-2 - Medium - CCI-000018 - V-248746 - SV-248746r853802_rule
RMF Control
AC-2
Severity
Medium
CCI
CCI-000018
Version
OL08-00-030172
Vuln IDs
  • V-248746
Rule IDs
  • SV-248746r853802_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000303-GPOS-00120, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000476-GPOS-00221
Checks: C-52180r779802_chk

Verify OL 8 generates audit records for all account creations, modifications, disabling, and termination events that affect "/etc/sudoers.d/". Check the auditing rules in "/etc/audit/audit.rules" with the following command: $ sudo grep /etc/sudoers.d/ /etc/audit/audit.rules -w /etc/sudoers.d/ -p wa -k identity If the command does not return a line, or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52134r779803_fix

Configure OL 8 to generate audit records for all account creations, modifications, disabling, and termination events that affect "/etc/sudoers.d/". Add or update the following file system rule to "/etc/audit/rules.d/audit.rules": -w /etc/sudoers.d/ -p wa -k identity The audit daemon must be restarted for the changes to take effect. $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "su" command.
AU-3 - Medium - CCI-000130 - V-248747 - SV-248747r853803_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030190
Vuln IDs
  • V-248747
Rule IDs
  • SV-248747r853803_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The "su" command allows a user to run commands with a substitute user and group ID. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210, SRG-OS-000471-GPOS-00215
Checks: C-52181r779805_chk

Verify OL 8 generates audit records for any use of the "su" command by running the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -iw /usr/bin/su /etc/audit/audit.rules -a always,exit -F path=/usr/bin/su -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-priv_change If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52135r779806_fix

Configure OL 8 to generate audit records for any use of the "su" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/su -F perm=x -F auid>=1000 -F auid!=unset -k privileged-priv_change The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
The OL 8 audit system must be configured to audit any use of the "setxattr", "fsetxattr", "lsetxattr", "removexattr", "fremovexattr", and "lremovexattr" system calls.
AU-3 - Medium - CCI-000130 - V-248748 - SV-248748r853804_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030200
Vuln IDs
  • V-248748
Rule IDs
  • SV-248748r853804_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). "Setxattr" is a system call used to set an extended attribute value. "Fsetxattr" is a system call used to set an extended attribute value. This is used to set extended attributes on a file. "Lsetxattr" is a system call used to set an extended attribute value. This is used to set extended attributes on a symbolic link. "Removexattr" is a system call that removes extended attributes. "Fremovexattr" is a system call that removes extended attributes. This is used for removal of extended attributes from a file. "Lremovexattr" is a system call that removes extended attributes. This is used for removal of extended attributes from symbolic links. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each syscall that all programs on the system makes. Therefore, it is very important to only use syscall rules when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. Performance can be helped, though, by combining syscalls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000458-GPOS-00203, SRG-OS-000462-GPOS-00206, SRG-OS-000463-GPOS-00207, SRG-OS-000466-GPOS-00210, SRG-OS-000468-GPOS-00212, SRG-OS-000471-GPOS-00215, SRG-OS-000474-GPOS-00219
Checks: C-52182r818667_chk

Verify if OL 8 is configured to audit the execution of the "setxattr", "fsetxattr", "lsetxattr", "removexattr", "fremovexattr", and "lremovexattr" system calls by running the following command: $ sudo grep xattr /etc/audit/audit.rules -a always,exit -F arch=b32 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid&gt;=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid&gt;=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b32 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid=0 -k perm_mod -a always,exit -F arch=b64 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid=0 -k perm_mod If the command does not return an audit rule for "setxattr", "fsetxattr", "lsetxattr", "removexattr", "fremovexattr", and "lremovexattr" or any of the lines returned are commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52136r818668_fix

Configure OL 8 to audit the execution of the "setxattr", "fsetxattr", "lsetxattr", "removexattr", "fremovexattr", and "lremovexattr" system calls by adding or updating the following lines to "/etc/audit/rules.d/audit.rules": -a always,exit -F arch=b32 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b32 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid=0 -k perm_mod -a always,exit -F arch=b64 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid=0 -k perm_mod The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "chage" command.
AU-3 - Medium - CCI-000130 - V-248753 - SV-248753r853805_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030250
Vuln IDs
  • V-248753
Rule IDs
  • SV-248753r853805_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The "chage" command is used to change or view user password expiry information. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000468-GPOS-00212, SRG-OS-000471-GPOS-00215
Checks: C-52187r779823_chk

Verify OL 8 generates an audit event for any use of the "chage" command by running the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w chage /etc/audit/audit.rules -a always,exit -F path=/usr/bin/chage -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-chage If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52141r779824_fix

Configure the audit system to generate an audit event for any use of the "chage" command by adding or updating the following rule in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F path=/usr/bin/chage -F perm=x -F auid>=1000 -F auid!=unset -k privileged-chage The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any uses of the "chcon" command.
AU-3 - Medium - CCI-000130 - V-248754 - SV-248754r853806_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030260
Vuln IDs
  • V-248754
Rule IDs
  • SV-248754r853806_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The "chcon" command is used to change file SELinux security context. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000468-GPOS-00212, SRG-OS-000471-GPOS-00215
Checks: C-52188r779826_chk

Verify OL 8 generates an audit record for any use of the "chcon" command by running the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w chcon /etc/audit/audit.rules -a always,exit -F path=/usr/bin/chcon -F perm=x -F auid&gt;=1000 -F auid!=unset -k perm_chng If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52142r779827_fix

Configure the audit system to generate an audit event for any use of the "chcon" command by adding or updating the following rule in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F path=/usr/bin/chcon -F perm=x -F auid>=1000 -F auid!=unset -k perm_chng The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "ssh-agent" command.
AU-3 - Medium - CCI-000130 - V-248756 - SV-248756r853807_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030280
Vuln IDs
  • V-248756
Rule IDs
  • SV-248756r853807_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The "ssh-agent" is a program to hold private keys used for public key authentication. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
Checks: C-52190r779832_chk

Verify OL 8 generates an audit record for any use of the "ssh-agent" command by running the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep ssh-agent /etc/audit/audit.rules -a always,exit -F path=/usr/bin/ssh-agent -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-ssh If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52144r779833_fix

Configure the audit system to generate an audit event for any use of the "ssh-agent" command by adding or updating the following rule in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F path=/usr/bin/ssh-agent -F perm=x -F auid>=1000 -F auid!=unset -k privileged-ssh The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "passwd" command.
AU-3 - Medium - CCI-000130 - V-248757 - SV-248757r853808_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030290
Vuln IDs
  • V-248757
Rule IDs
  • SV-248757r853808_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The "passwd" command is used to change passwords for user accounts. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
Checks: C-52191r779835_chk

Verify OL 8 generates an audit event for any use of the "passwd" command by running the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w passwd /etc/audit/audit.rules -a always,exit -F path=/usr/bin/passwd -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-passwd If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52145r779836_fix

Configure the audit system to generate an audit event for any use of the "passwd" command by adding or updating the following rule in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F path=/usr/bin/passwd -F perm=x -F auid>=1000 -F auid!=unset -k privileged-passwd The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "mount" command.
AU-3 - Medium - CCI-000130 - V-248758 - SV-248758r853809_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030300
Vuln IDs
  • V-248758
Rule IDs
  • SV-248758r853809_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The "mount" command is used to mount a filesystem. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
Checks: C-52192r779838_chk

Verify OL 8 generates an audit event for any use of the "mount" command by running the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w /usr/bin/mount /etc/audit/audit.rules -a always,exit -F path=/usr/bin/mount -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-mount If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52146r779839_fix

Configure the audit system to generate an audit event for any use of the "mount" command by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F path=/usr/bin/mount -F perm=x -F auid>=1000 -F auid!=unset -k privileged-mount The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "umount" command.
AU-3 - Medium - CCI-000130 - V-248759 - SV-248759r853810_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030301
Vuln IDs
  • V-248759
Rule IDs
  • SV-248759r853810_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The "mount" command is used to mount a filesystem. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
Checks: C-52193r779841_chk

Verify OL 8 generates an audit event for any use of the "umount" command by running the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w /usr/bin/umount /etc/audit/audit.rules -a always,exit -F path=/usr/bin/umount -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-mount If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52147r779842_fix

Configure the audit system to generate an audit event for any use of the "umount" command by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F path=/usr/bin/umount -F perm=x -F auid>=1000 -F auid!=unset -k privileged-mount The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "mount" syscall.
AU-3 - Medium - CCI-000130 - V-248760 - SV-248760r853811_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030302
Vuln IDs
  • V-248760
Rule IDs
  • SV-248760r853811_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The "mount" command is used to mount a filesystem. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
Checks: C-52194r779844_chk

Verify OL 8 generates an audit event for any use of the "mount" syscall by running the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w mount /etc/audit/audit.rules -a always,exit -F arch=b32 -S mount -F auid&gt;=1000 -F auid!=unset -k privileged-mount -a always,exit -F arch=b64 -S mount -F auid&gt;=1000 -F auid!=unset -k privileged-mount If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52148r779845_fix

Configure the audit system to generate an audit event for any use of the "mount" syscall by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S mount -F auid>=1000 -F auid!=unset -k privileged-mount -a always,exit -F arch=b64 -S mount -F auid>=1000 -F auid!=unset -k privileged-mount The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "unix_update" command.
AU-3 - Medium - CCI-000130 - V-248761 - SV-248761r853812_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030310
Vuln IDs
  • V-248761
Rule IDs
  • SV-248761r853812_rule
Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information. At a minimum, the organization must audit the full-text recording of privileged commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. "Unix_update" is a helper program for the "pam_unix" module that updates the password for a given user. It is not intended to be run directly from the command line and logs a security violation in that event. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
Checks: C-52195r779847_chk

Verify OL 8 generates an audit event for any use of the "unix_update" command by running the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w "unix_update" /etc/audit/audit.rules -a always,exit -F path=/usr/sbin/unix_update -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-unix-update If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52149r779848_fix

Configure the audit system to generate an audit event for any use of the "unix_update" command by adding or updating the following rule in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F path=/usr/sbin/unix_update -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "postdrop" command.
AU-3 - Medium - CCI-000130 - V-248762 - SV-248762r853813_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030311
Vuln IDs
  • V-248762
Rule IDs
  • SV-248762r853813_rule
Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information. At a minimum, the organization must audit the full-text recording of privileged commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. The "postdrop" command creates a file in the maildrop directory and copies its standard input to the file. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
Checks: C-52196r779850_chk

Verify OL 8 generates an audit event for any use of the "postdrop" command by running the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w "postdrop" /etc/audit/audit.rules -a always,exit -F path=/usr/sbin/postdrop -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-unix-update If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52150r779851_fix

Configure the audit system to generate an audit event for any use of the "postdrop" command by adding or updating the following rule in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F path=/usr/sbin/postdrop -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "postqueue" command.
AU-3 - Medium - CCI-000130 - V-248763 - SV-248763r853814_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030312
Vuln IDs
  • V-248763
Rule IDs
  • SV-248763r853814_rule
Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information. At a minimum, the organization must audit the full-text recording of privileged commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. The "postqueue" command implements the Postfix user interface for queue management. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
Checks: C-52197r779853_chk

Verify OL 8 generates an audit event for any use of the "postqueue" command by running the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w "postqueue" /etc/audit/audit.rules -a always,exit -F path=/usr/sbin/postqueue -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-unix-update If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52151r779854_fix

Configure the audit system to generate an audit event for any use of the "postqueue" command by adding or updating the following rule in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F path=/usr/sbin/postqueue -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "semanage" command.
AU-12 - Medium - CCI-000169 - V-248764 - SV-248764r779858_rule
RMF Control
AU-12
Severity
Medium
CCI
CCI-000169
Version
OL08-00-030313
Vuln IDs
  • V-248764
Rule IDs
  • SV-248764r779858_rule
Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information. At a minimum, the organization must audit the full-text recording of privileged commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. The "semanage" command is used to configure certain elements of SELinux policy without requiring modification to or recompilation from policy sources. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way.
Checks: C-52198r779856_chk

Verify if OL 8 is configured to audit the execution of the "semanage" command by running the following command: $ sudo grep -w semanage /etc/audit/audit.rules a always,exit -F path=/usr/sbin/semanage -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-unix-update If the command does not return all lines or the lines are commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52152r779857_fix

Configure OL 8 to audit the execution of the "semanage" command by adding or updating the following lines to "/etc/audit/rules.d/audit.rules": a always,exit -F path=/usr/sbin/semanage -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "setfiles" command.
AU-12 - Medium - CCI-000169 - V-248765 - SV-248765r779861_rule
RMF Control
AU-12
Severity
Medium
CCI
CCI-000169
Version
OL08-00-030314
Vuln IDs
  • V-248765
Rule IDs
  • SV-248765r779861_rule
Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information. At a minimum, the organization must audit the full-text recording of privileged commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. The "setfiles" command is primarily used to initialize the security context fields (extended attributes) on one or more filesystems (or parts of them). Usually it is initially run as part of the SELinux installation process (a step commonly known as labeling). When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way.
Checks: C-52199r779859_chk

Verify OL 8 is configured to audit the execution of the "setfiles" command by running the following command: $ sudo grep -w setfiles /etc/audit/audit.rules -a always,exit -F path=/usr/sbin/setfiles -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-unix-update If the command does not return all lines or the lines are commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52153r779860_fix

Configure OL 8 to audit the execution of the "setfiles" command by adding or updating the following lines to "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/sbin/setfiles -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "userhelper" command.
AU-12 - Medium - CCI-000169 - V-248766 - SV-248766r779864_rule
RMF Control
AU-12
Severity
Medium
CCI
CCI-000169
Version
OL08-00-030315
Vuln IDs
  • V-248766
Rule IDs
  • SV-248766r779864_rule
Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information. At a minimum, the organization must audit the full-text recording of privileged commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. The "userhelper" command is not intended to be run interactively. "Userhelper" provides a basic interface to change a user's password, gecos information, and shell. The main difference between this program and its traditional equivalents (passwd, chfn, chsh) is that prompts are written to standard out to make it easy for a graphical user interface wrapper to interface to it as a child process. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way.
Checks: C-52200r779862_chk

Verify OL 8 is configured to audit the execution of the "userhelper" command by running the following command: $ sudo grep -w userhelper /etc/audit/audit.rules -a always,exit -F path=/usr/sbin/userhelper -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-unix-update If the command does not return all lines or the lines are commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52154r779863_fix

Configure OL 8 to audit the execution of the "userhelper" command by adding or updating the following lines to "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/sbin/userhelper -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "setsebool" command.
AU-3 - Medium - CCI-000130 - V-248767 - SV-248767r853815_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030316
Vuln IDs
  • V-248767
Rule IDs
  • SV-248767r853815_rule
Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information. At a minimum, the organization must audit the full-text recording of privileged commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. The "setsebool" command sets the current state of a particular SELinux boolean or a list of booleans to a given value. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
Checks: C-52201r779865_chk

Verify OL 8 is configured to audit the execution of the "setsebool" command by running the following command: $ sudo grep -w setsebool /etc/audit/audit.rules -a always,exit -F path=/usr/sbin/setsebool -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-unix-update If the command does not return all lines or the lines are commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52155r779866_fix

Configure OL 8 to audit the execution of the "setsebool" command by adding or updating the following lines to "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/sbin/setsebool -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "unix_chkpwd" command.
AU-3 - Medium - CCI-000130 - V-248768 - SV-248768r853816_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030317
Vuln IDs
  • V-248768
Rule IDs
  • SV-248768r853816_rule
Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information. At a minimum, the organization must audit the full-text recording of privileged commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. The "unix_chkpwd" command is a helper program for the pam_unix module that verifies the password of the current user. It also checks password and account expiration dates in shadow. It is not intended to be run directly from the command line and logs a security violation if done so. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
Checks: C-52202r779868_chk

Verify OL 8 is configured to audit the execution of the "unix_chkpwd" command by running the following command: $ sudo grep -w unix_chkpwd /etc/audit/audit.rules -a always,exit -F path=/usr/sbin/unix_chkpwd -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-unix-update If the command does not return all lines or the lines are commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52156r779869_fix

Configure OL 8 to audit the execution of the "unix_chkpwd" command by adding or updating the following lines to "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/sbin/unix_chkpwd -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "ssh-keysign" command.
AU-3 - Medium - CCI-000130 - V-248769 - SV-248769r853817_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030320
Vuln IDs
  • V-248769
Rule IDs
  • SV-248769r853817_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The "ssh-keysign" program is an SSH helper program for host-based authentication. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
Checks: C-52203r779871_chk

Verify OL 8 generates an audit record for any use of "ssh-keysign" by running the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep ssh-keysign /etc/audit/audit.rules -a always,exit -F path=/usr/libexec/openssh/ssh-keysign -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-ssh If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52157r779872_fix

Configure the audit system to generate an audit event for any use of "ssh-keysign" by adding or updating the following rule in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F path=/usr/libexec/openssh/ssh-keysign -F perm=x -F auid>=1000 -F auid!=unset -k privileged-ssh The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "setfacl" command.
AU-3 - Medium - CCI-000130 - V-248770 - SV-248770r853818_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030330
Vuln IDs
  • V-248770
Rule IDs
  • SV-248770r853818_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The "setfacl" command is used to set file access control lists. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
Checks: C-52204r779874_chk

Verify OL 8 generates an audit record for any use of the "setfacl" command by running the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w setfacl /etc/audit/audit.rules -a always,exit -F path=/usr/bin/setfacl -F perm=x -F auid&gt;=1000 -F auid!=unset -k perm_chng If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52158r779875_fix

Configure the audit system to generate an audit event for any use of the "setfacl" command by adding or updating the following rule in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F path=/usr/bin/setfacl -F perm=x -F auid>=1000 -F auid!=unset -k perm_chng The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "pam_timestamp_check" command.
AU-3 - Medium - CCI-000130 - V-248771 - SV-248771r853819_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030340
Vuln IDs
  • V-248771
Rule IDs
  • SV-248771r853819_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The "pam_timestamp_check" command is used to check if the default timestamp is valid. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
Checks: C-52205r779877_chk

Verify OL 8 generates an audit event for any use of the "pam_timestamp_check" command by running the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w pam_timestamp_check /etc/audit/audit.rules -a always,exit -F path=/usr/sbin/pam_timestamp_check -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-pam_timestamp_check If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52159r779878_fix

Configure the audit system to generate an audit event for any use of the "pam_timestamp_check" command by adding or updating the following rule in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F path=/usr/sbin/pam_timestamp_check -F perm=x -F auid>=1000 -F auid!=unset -k privileged-pam_timestamp_check The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "newgrp" command.
AU-3 - Medium - CCI-000130 - V-248772 - SV-248772r853820_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030350
Vuln IDs
  • V-248772
Rule IDs
  • SV-248772r853820_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The "newgrp" command is used to change the current group ID during a login session. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
Checks: C-52206r779880_chk

Verify OL 8 generates an audit record for any use of the "newgrp" command by running the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w newgrp /etc/audit/audit.rules -a always,exit -F path=/usr/bin/newgrp -F perm=x -F auid&gt;=1000 -F auid!=unset -k priv_cmd If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52160r779881_fix

Configure the audit system to generate an audit event for any use of the "newgrp" command by adding or updating the following rule in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F path=/usr/bin/newgrp -F perm=x -F auid>=1000 -F auid!=unset -k priv_cmd The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "init_module" and "finit_module" system calls.
AU-3 - Medium - CCI-000130 - V-248773 - SV-248773r853821_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030360
Vuln IDs
  • V-248773
Rule IDs
  • SV-248773r853821_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The "init_module" and "finit_module" system calls are used to load a kernel module. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each syscall that all programs on the system makes. Therefore, it is very important to only use syscall rules when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. Performance can be helped, though, by combining syscalls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
Checks: C-52207r818670_chk

Verify OL 8 generates an audit record for any use of the "init_module" and "finit_module" system calls by running the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep init_module /etc/audit/audit.rules -a always,exit -F arch=b32 -S init_module,finit_module -F auid&gt;=1000 -F auid!=unset -k module_chng -a always,exit -F arch=b64 -S init_module,finit_module -F auid&gt;=1000 -F auid!=unset -k module_chng If the command does not return an audit rule for "init_module" and "finit_module" or any of the lines returned are commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52161r818671_fix

Configure the audit system to generate an audit event for any use of the "init_module" and "finit_module" system calls by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S init_module,finit_module -F auid>=1000 -F auid!=unset -k module_chng -a always,exit -F arch=b64 -S init_module,finit_module -F auid>=1000 -F auid!=unset -k module_chng The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "rename", "unlink", "rmdir", "renameat", and "unlinkat" system calls.
AU-3 - Medium - CCI-000130 - V-248774 - SV-248774r853822_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030361
Vuln IDs
  • V-248774
Rule IDs
  • SV-248774r853822_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The "rename" system call will rename the specified files by replacing the first occurrence of expression in their name by replacement. The "unlink" system call deletes a name from the filesystem. If that name was the last link to a file and no processes have the file open, the file is deleted and the space it was using is made available for reuse. The "rmdir" system call removes empty directories. The "renameat" system call renames a file, moving it between directories, if required. The "unlinkat" system call operates in exactly the same way as either "unlink" or "rmdir" except for the differences described in the manual page. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each syscall that all programs on the system makes. Therefore, it is very important to only use syscall rules when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. Performance can be helped, though, by combining syscalls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
Checks: C-52208r818673_chk

Verify OL 8 is configured to generate audit records for any use of the "rename", "unlink", "rmdir", "renameat", and "unlinkat" system calls by running the following command: $ sudo grep 'rename\|unlink\|rmdir' /etc/audit/audit.rules -a always,exit -F arch=b32 -S rename,unlink,rmdir,renameat,unlinkat -F auid&gt;=1000 -F auid!=unset -k delete -a always,exit -F arch=b64 -S rename,unlink,rmdir,renameat,unlinkat -F auid&gt;=1000 -F auid!=unset -k delete If the command does not return an audit rule for "rename", "unlink", "rmdir", "renameat" and "unlinkat" or any of the lines returned are commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52162r818674_fix

Configure OL 8 to generate audit records for any use of the "rename", "unlink", "rmdir", "renameat", and "unlinkat" system calls by adding or updating the following lines to "/etc/audit/rules.d/audit.rules": -a always,exit -F arch=b32 -S rename,unlink,rmdir,renameat,unlinkat -F success=1 -F auid>=1000 -F auid!=unset -k delete -a always,exit -F arch=b64 -S rename,unlink,rmdir,renameat,unlinkat -F success=1 -F auid>=1000 -F auid!=unset -k delete The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "gpasswd" command.
AU-3 - Medium - CCI-000130 - V-248779 - SV-248779r853823_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030370
Vuln IDs
  • V-248779
Rule IDs
  • SV-248779r853823_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The "gpasswd" command is used to administer "/etc/group" and "/etc/gshadow". Every group can have administrators, members, and a password. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
Checks: C-52213r779901_chk

Verify OL 8 generates an audit event for any use of the "gpasswd" command by running the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w gpasswd /etc/audit/audit.rules -a always,exit -F path=/usr/bin/gpasswd -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-gpasswd If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52167r779902_fix

Configure the audit system to generate an audit event for any use of the "gpasswd" command by adding or updating the following rule in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F path=/usr/bin/gpasswd -F perm=x -F auid>=1000 -F auid!=unset -k privileged-gpasswd The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the delete_module syscall.
AU-3 - Medium - CCI-000130 - V-248781 - SV-248781r853824_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030390
Vuln IDs
  • V-248781
Rule IDs
  • SV-248781r853824_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The "delete_module" command is used to unload a kernel module. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
Checks: C-52215r779907_chk

Verify OL 8 generates an audit record for any use of the "delete_module" syscall by running the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w "delete_module" /etc/audit/audit.rules -a always,exit -F arch=b32 -S delete_module -F auid&gt;=1000 -F auid!=unset -k module_chng -a always,exit -F arch=b64 -S delete_module -F auid&gt;=1000 -F auid!=unset -k module_chng If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52169r779908_fix

Configure the audit system to generate an audit event for any use of the "delete_module" syscall by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S delete_module -F auid>=1000 -F auid!=unset -k module_chng -a always,exit -F arch=b64 -S delete_module -F auid>=1000 -F auid!=unset -k module_chng The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "crontab" command.
AU-3 - Medium - CCI-000130 - V-248782 - SV-248782r853825_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030400
Vuln IDs
  • V-248782
Rule IDs
  • SV-248782r853825_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The "crontab" command is used to maintain crontab files for individual users. Crontab is the program used to install, remove, or list the tables used to drive the cron daemon. This is similar to the task scheduler used in other operating systems. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
Checks: C-52216r779910_chk

Verify OL 8 generates an audit event for any use of the "crontab" command by running the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w crontab /etc/audit/audit.rules -a always,exit -F path=/usr/bin/crontab -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-crontab If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52170r779911_fix

Configure the audit system to generate an audit event for any use of the "crontab" command by adding or updating the following rule in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F path=/usr/bin/crontab -F perm=x -F auid>=1000 -F auid!=unset -k privileged-crontab The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "chsh" command.
AU-3 - Medium - CCI-000130 - V-248783 - SV-248783r853826_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030410
Vuln IDs
  • V-248783
Rule IDs
  • SV-248783r853826_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The "chsh" command is used to change the login shell. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
Checks: C-52217r779913_chk

Verify OL 8 generates an audit record for any use of the "chsh" command by running the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w chsh /etc/audit/audit.rules -a always,exit -F path=/usr/bin/chsh -F perm=x -F auid&gt;=1000 -F auid!=unset -k priv_cmd If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52171r779914_fix

Configure the audit system to generate an audit event for any use of the "chsh" command by adding or updating the following rule in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F path=/usr/bin/chsh -F perm=x -F auid>=1000 -F auid!=unset -k priv_cmd The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "truncate", "ftruncate", "creat", "open", "openat", and "open_by_handle_at" system calls.
AU-3 - Medium - CCI-000130 - V-248784 - SV-248784r853827_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030420
Vuln IDs
  • V-248784
Rule IDs
  • SV-248784r853827_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The "truncate" and "ftruncate" functions are used to truncate a file to a specified length. The "creat" system call is used to open and possibly create a file or device. The "open" system call opens a file specified by a pathname. If the specified file does not exist, it may optionally be created by "open". The "openat" system call opens a file specified by a relative pathname. The "name_to_handle_at" and "open_by_handle_at" system calls split the functionality of openat into two parts: "name_to_handle_at" returns an opaque handle that corresponds to a specified file; "open_by_handle_at" opens the file corresponding to a handle returned by a previous call to "name_to_handle_at" and returns an open file descriptor. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each syscall that all programs on the system makes. Therefore, it is very important to only use syscall rules when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. Performance can be helped, though, by combining syscalls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000064-GPOS-00033, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
Checks: C-52218r818676_chk

Verify OL 8 generates an audit record for any use of the "truncate", "ftruncate", "creat", "open", "openat", and "open_by_handle_at" system calls by running the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep 'open\|truncate\|creat' /etc/audit/audit.rules -a always,exit -F arch=b32 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EPERM -F auid&gt;=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b64 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EPERM -F auid&gt;=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b32 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EACCES -F auid&gt;=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b64 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EACCES -F auid&gt;=1000 -F auid!=unset -k perm_access If the output does not produce rules containing "-F exit=-EPERM", this is a finding. If the output does not produce rules containing "-F exit=-EACCES", this is a finding. If the command does not return an audit rule for "truncate", "ftruncate", "creat", "open", "openat", and "open_by_handle_at" or any of the lines returned are commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52172r818677_fix

Configure the audit system to generate an audit event for any use of the "truncate", "ftruncate", "creat", "open", "openat", and "open_by_handle_at" system calls by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EPERM -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b64 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EPERM -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b32 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EACCES -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b64 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EACCES -F auid>=1000 -F auid!=unset -k perm_access The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "chown", "fchown", "fchownat", and "lchown" system calls.
AU-3 - Medium - CCI-000130 - V-248790 - SV-248790r853828_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030480
Vuln IDs
  • V-248790
Rule IDs
  • SV-248790r853828_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The "chown" command is used to change file owner and group. The "fchown" system call is used to change the ownership of a file referred to by the open file descriptor. The "fchownat" system call is used to change ownership of a file relative to a directory file descriptor. The "lchown" system call is used to change the ownership of the file specified by a path, which does not dereference symbolic links. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each syscall that all programs on the system makes. Therefore, it is very important to only use syscall rules when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. Performance can be helped, though, by combining syscalls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000064-GPOS-00033, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210, SRG-OS-000471-GPOS-00215
Checks: C-52224r818679_chk

Verify OL 8 generates an audit record for any use of the "chown", "fchown", "fchownat", and "lchown" system calls by running the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep chown /etc/audit/audit.rules -a always,exit -F arch=b32 -S chown,fchown,fchownat,lchown -F auid&gt;=1000 -F auid!=unset -k perm_chng -a always,exit -F arch=b64 -S chown,fchown,fchownat,lchown -F auid&gt;=1000 -F auid!=unset -k perm_chng If audit rules are not defined for "chown", "fchown", "fchownat", and "lchown" or any of the lines returned are commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52178r818680_fix

Configure the audit system to generate an audit event for any use of the "chown", "fchown", "fchownat", and "lchown" system calls by adding or updating the following line to "/etc/audit/rules.d/audit.rules": -a always,exit -F arch=b32 -S chown,fchown,fchownat,lchown -F auid>=1000 -F auid!=unset -k perm_chng -a always,exit -F arch=b64 -S chown,fchown,fchownat,lchown -F auid>=1000 -F auid!=unset -k perm_chng The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "chmod", "fchmod", and "fchmodat" system calls.
AU-3 - Medium - CCI-000130 - V-248791 - SV-248791r853829_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030490
Vuln IDs
  • V-248791
Rule IDs
  • SV-248791r853829_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The "chmod" system call changes the file mode bits of each given file according to mode, which can be either a symbolic representation of changes to make or an octal number representing the bit pattern for the new mode bits. The "fchmod" system call is used to change permissions of a file. The "fchmodat" system call is used to change permissions of a file relative to a directory file descriptor. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each syscall that all programs on the system makes. Therefore, it is very important to only use syscall rules when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. Performance can be helped, though, by combining syscalls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000064-GPOS-00033, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210, SRG-OS-000471-GPOS-00215
Checks: C-52225r818682_chk

Verify OL 8 generates an audit record for any use of the "chmod","fchmod", and "fchmodat" syscalls by running the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep chmod /etc/audit/audit.rules -a always,exit -F arch=b32 -S chmod,fchmod,fchmodat -F auid&gt;=1000 -F auid!=unset -k perm_chng -a always,exit -F arch=b64 -S chmod,fchmod,fchmodat -F auid&gt;=1000 -F auid!=unset -k perm_chng If the command does not return an audit rule for "chmod", "fchmod", and "fchmodat", or any of the lines returned are commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52179r818683_fix

Configure the audit system to generate an audit event for any use of the "chmod", "fchmod", and "fchmodat" syscalls by adding or updating the following line to "/etc/audit/rules.d/audit.rules": -a always,exit -F arch=b32 -S chmod,fchmod,fchmodat -F auid>=1000 -F auid!=unset -k perm_chng -a always,exit -F arch=b64 -S chmod,fchmod,fchmodat -F auid>=1000 -F auid!=unset -k perm_chng The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "sudo" command.
AU-3 - Medium - CCI-000130 - V-248797 - SV-248797r853830_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030550
Vuln IDs
  • V-248797
Rule IDs
  • SV-248797r853830_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The "sudo" command allows a permitted user to execute a command as the superuser or another user as specified by the security policy. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210, SRG-OS-000471-GPOS-00215
Checks: C-52231r779955_chk

Verify OL 8 generates an audit event for any use of the "sudo" command by running the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w sudo /etc/audit/audit.rules -a always,exit -F path=/usr/bin/sudo -F perm=x -F auid&gt;=1000 -F auid!=unset -k priv_cmd If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52185r779956_fix

Configure the audit system to generate an audit event for any use of the "sudo" command by adding or updating the following rule in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F path=/usr/bin/sudo -F perm=x -F auid>=1000 -F auid!=unset -k priv_cmd The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "usermod" command.
AU-3 - Medium - CCI-000130 - V-248798 - SV-248798r853831_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030560
Vuln IDs
  • V-248798
Rule IDs
  • SV-248798r853831_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The "usermod" command modifies the system account files to reflect the changes that are specified on the command line. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210, SRG-OS-000471-GPOS-00215
Checks: C-52232r779958_chk

Verify OL 8 generates an audit event for any use of the "usermod" command by running the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w usermod /etc/audit/audit.rules -a always,exit -F path=/usr/sbin/usermod -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-usermod If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52186r779959_fix

Configure the audit system to generate an audit event for any use of the "usermod" command by adding or updating the following rule in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F path=/usr/sbin/usermod -F perm=x -F auid>=1000 -F auid!=unset -k privileged-usermod The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "chacl" command.
AU-3 - Medium - CCI-000130 - V-248799 - SV-248799r853832_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030570
Vuln IDs
  • V-248799
Rule IDs
  • SV-248799r853832_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The "chacl" command is used to change the access control list of a file or directory. When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to "-1". The AUID representation is an unsigned 32-bit integer, which equals "4294967295". The audit system interprets "-1", "4294967295", and "unset" in the same way. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210, SRG-OS-000471-GPOS-00215
Checks: C-52233r779961_chk

Verify OL 8 generates an audit record for any use of the "chacl" command by running the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w chacl /etc/audit/audit.rules -a always,exit -F path=/usr/bin/chacl -F perm=x -F auid&gt;=1000 -F auid!=unset -k perm_chng If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52187r779962_fix

Configure the audit system to generate an audit event for any use of the "chacl" command by adding or updating the following rule in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F path=/usr/bin/chacl -F perm=x -F auid>=1000 -F auid!=unset -k perm_chng The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any use of the "kmod" command.
AU-3 - Medium - CCI-000130 - V-248800 - SV-248800r853833_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030580
Vuln IDs
  • V-248800
Rule IDs
  • SV-248800r853833_rule
Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The "kmod" command is used to control Linux Kernel modules. The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which OL 8 will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000471-GPOS-00216, SRG-OS-000477-GPOS-00222
Checks: C-52234r779964_chk

Verify OL 8 is configured to audit the execution of the module management program "kmod" by running the following command: $ sudo grep "/usr/bin/kmod" /etc/audit/audit.rules -w /usr/bin/kmod -p x -k modules If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52188r779965_fix

Configure OL 8 to audit the execution of the module management program "kmod" by adding or updating the following line to "/etc/audit/rules.d/audit.rules": -w /usr/bin/kmod -p x -k modules The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any attempted modifications to the "faillock" log file.
AU-3 - Medium - CCI-000130 - V-248801 - SV-248801r853834_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030590
Vuln IDs
  • V-248801
Rule IDs
  • SV-248801r853834_rule
Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which OL 8 will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. From "Pam_Faillock man" pages: Note the default directory that "pam_faillock" uses is usually cleared on system boot so the access will be reenabled after system reboot. If that is undesirable, a different tally directory must be set with the "dir" option. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000473-GPOS-00218
Checks: C-52235r779967_chk

Verify OL 8 generates an audit record for any attempted modifications to the "faillock" file. Determine where the faillock tallies are stored with the following commands: For OL versions 8.0 and 8.1: $ sudo grep -i pam_faillock.so /etc/pam.d/system-auth auth required pam_faillock.so preauth dir=/var/log/faillock silent deny=3 fail_interval=900 even_deny_root For OL versions 8.2 and newer: $ sudo grep dir /etc/security/faillock.conf dir=/var/log/faillock Using the location of the faillock log file, check that the following calls are being audited by running the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w faillock /etc/audit/audit.rules -w /var/log/faillock -p wa -k logins If the command does not return a line or the line is commented out, this is a finding.

Fix: F-52189r779968_fix

Configure the audit system to generate an audit event for any attempted modifications to the "faillock" file by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -w /var/log/faillock -p wa -k logins The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must generate audit records for any attempted modifications to the "lastlog" file.
AU-3 - Medium - CCI-000130 - V-248802 - SV-248802r853835_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030600
Vuln IDs
  • V-248802
Rule IDs
  • SV-248802r853835_rule
Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which OL 8 will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000473-GPOS-00218
Checks: C-52236r779970_chk

Verify OL 8 generates an audit record for any attempted modifications to the "lastlog" file by running the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w lastlog /etc/audit/audit.rules -w /var/log/lastlog -p wa -k logins If the command does not return a line or the line is commented out, this is a finding. Note: The "-k" allows for specifying an arbitrary identifier, and the string after it does not need to match the example output above.

Fix: F-52190r779971_fix

Configure the audit system to generate an audit event for any attempted modifications to the "lastlog" file by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -w /var/log/lastlog -p wa -k logins The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: $ sudo service auditd restart

b
OL 8 must enable auditing of processes that start prior to the audit daemon.
AU-3 - Medium - CCI-000130 - V-248803 - SV-248803r853836_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030601
Vuln IDs
  • V-248803
Rule IDs
  • SV-248803r853836_rule
Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which OL 8 will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000473-GPOS-00218
Checks: C-52237r779973_chk

Verify OL 8 enables auditing of processes that start prior to the audit daemon with the following commands: $ sudo grub2-editenv list | grep audit kernelopts=root=/dev/mapper/ol-root ro crashkernel=auto resume=/dev/mapper/ol-swap rd.lvm.lv=ol/root rd.lvm.lv=ol/swap rhgb quiet fips=1 audit=1 audit_backlog_limit=8192 boot=UUID=8d171156-cd61-421c-ba41-1c021ac29e82 If the "audit" entry does not equal "1", is missing, or the line is commented out, this is a finding. Check that auditing is enabled by default to persist in kernel updates: $ sudo grep audit /etc/default/grub GRUB_CMDLINE_LINUX="audit=1" If "audit" is not set to "1", is missing or commented out, this is a finding.

Fix: F-52191r779974_fix

Configure OL 8 to audit processes that start prior to the audit daemon with the following command: $ sudo grubby --update-kernel=ALL --args="audit=1" Add or modify the following line in "/etc/default/grub" to ensure the configuration survives kernel updates: GRUB_CMDLINE_LINUX="audit=1"

a
OL 8 must allocate an "audit_backlog_limit" of sufficient size to capture processes that start prior to the audit daemon.
AU-3 - Low - CCI-000130 - V-248804 - SV-248804r853837_rule
RMF Control
AU-3
Severity
Low
CCI
CCI-000130
Version
OL08-00-030602
Vuln IDs
  • V-248804
Rule IDs
  • SV-248804r853837_rule
Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. If auditing is enabled late in the startup process, the actions of some startup processes may not be audited. Some audit systems also maintain state information only available if auditing is enabled before a given process is created. Audit records can be generated from various components within the information system (e.g., module or policy filter). Allocating an "audit_backlog_limit" of sufficient size is critical in maintaining a stable boot process. With an insufficient limit allocated, the system is susceptible to boot failures and crashes. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
Checks: C-52238r779976_chk

Verify OL 8 allocates a sufficient "audit_backlog_limit" to capture processes that start prior to the audit daemon with the following commands: $ sudo grub2-editenv list | grep audit kernelopts=root=/dev/mapper/ol-root ro crashkernel=auto resume=/dev/mapper/ol-swap rd.lvm.lv=ol/root rd.lvm.lv=ol/swap rhgb quiet fips=1 audit=1 audit_backlog_limit=8192 boot=UUID=8d171156-cd61-421c-ba41-1c021ac29e82 If the "audit_backlog_limit" entry does not equal "8192" or larger, is missing, or the line is commented out, this is a finding. Verify "audit_backlog_limit" is set to persist in kernel updates: $ sudo grep audit /etc/default/grub GRUB_CMDLINE_LINUX="audit_backlog_limit=8192" If "audit_backlog_limit" is not set to "8192" or larger or is missing or commented out, this is a finding.

Fix: F-52192r779977_fix

Configure OL 8 to allocate sufficient "audit_backlog_limit" to capture processes that start prior to the audit daemon with the following command: $ sudo grubby --update-kernel=ALL --args="audit_backlog_limit=8192" Add or modify the following line in "/etc/default/grub" to ensure the configuration survives kernel updates: GRUB_CMDLINE_LINUX="audit_backlog_limit=8192" If audit records are not stored on a partition made specifically for audit records, a new partition with sufficient space will need be to be created.

b
OL 8 must enable Linux audit logging for the USBGuard daemon.
AU-12 - Medium - CCI-000172 - V-248805 - SV-248805r779981_rule
RMF Control
AU-12
Severity
Medium
CCI
CCI-000172
Version
OL08-00-030603
Vuln IDs
  • V-248805
Rule IDs
  • SV-248805r779981_rule
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter).
Checks: C-52239r779979_chk

Verify OL 8 enables Linux audit logging of the USBGuard daemon with the following commands. Note: If the USBGuard daemon is not installed and enabled, this requirement is not applicable. $ sudo grep -i auditbackend /etc/usbguard/usbguard-daemon.conf AuditBackend=LinuxAudit If the "AuditBackend" entry does not equal "LinuxAudit", is missing, or the line is commented out, this is a finding.

Fix: F-52193r779980_fix

Configure OL 8 to enable Linux audit logging of the USBGuard daemon by adding or modifying the following line in "/etc/usbguard/usbguard-daemon.conf": AuditBackend=LinuxAudit

b
OL 8 must allow only the Information System Security Manager (ISSM) (or individuals or roles appointed by the ISSM) to select which auditable events are to be audited.
AU-12 - Medium - CCI-000171 - V-248806 - SV-248806r779984_rule
RMF Control
AU-12
Severity
Medium
CCI
CCI-000171
Version
OL08-00-030610
Vuln IDs
  • V-248806
Rule IDs
  • SV-248806r779984_rule
Without the capability to restrict the roles and individuals that can select which events are audited, unauthorized personnel may be able to prevent the auditing of critical events. Misconfigured audits may degrade the system's performance by overwhelming the audit log. Misconfigured audits may also make it more difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one.
Checks: C-52240r779982_chk

Verify that the "/etc/audit/rules.d/audit.rules" and "/etc/audit/auditd.conf" file have a mode of "0640" or less permissive by using the following commands: $ sudo ls -al /etc/audit/rules.d/audit.rules -rw-r----- 1 root root 1280 Feb 16 17:09 audit.rules $ sudo ls -al /etc/audit/auditd.conf -rw-r----- 1 root root 621 Sep 22 2014 auditd.conf If the "/etc/audit/rules.d/audit.rules" or "/etc/audit/auditd.conf" files have a mode more permissive than "0640", this is a finding.

Fix: F-52194r779983_fix

Configure the "/etc/audit/rules.d/audit.rules" and "/etc/audit/auditd.conf" files to have a mode of "0640" with the following commands: $ sudo chmod 0640 /etc/audit/rules.d/audit.rules $ sudo chmod 0640 /etc/audit/auditd.conf

b
OL 8 audit tools must have a mode of "0755" or less permissive.
AU-9 - Medium - CCI-001493 - V-248807 - SV-248807r779987_rule
RMF Control
AU-9
Severity
Medium
CCI
CCI-001493
Version
OL08-00-030620
Vuln IDs
  • V-248807
Rule IDs
  • SV-248807r779987_rule
Protecting audit information includes identifying and protecting the tools used to view and manipulate log data. Therefore, protecting audit tools is necessary to prevent unauthorized operation on audit information. OL 8 systems providing tools to interface with audit information will leverage user permissions and roles identifying the user accessing the tools, and the corresponding user rights, to make access decisions regarding the access to audit tools. Audit tools include but are not limited to vendor-provided and open source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators.
Checks: C-52241r779985_chk

Verify the audit tools are protected from unauthorized access, deletion, or modification by checking the permissive mode. Check the octal permission of each audit tool by running the following command: $ sudo stat -c "%a %n" /sbin/auditctl /sbin/aureport /sbin/ausearch /sbin/autrace /sbin/auditd /sbin/rsyslogd /sbin/augenrules 755 /sbin/auditctl 755 /sbin/aureport 755 /sbin/ausearch 750 /sbin/autrace 755 /sbin/auditd 755 /sbin/rsyslogd 755 /sbin/augenrules If any of the audit tools has a mode more permissive than "0755", this is a finding.

Fix: F-52195r779986_fix

Configure the audit tools to be protected from unauthorized access by setting the correct permissive mode using the following command: $ sudo chmod 0755 [audit_tool] Replace "[audit_tool]" with the audit tool that does not have the correct permissive mode.

b
OL 8 audit tools must be owned by root.
AU-9 - Medium - CCI-001493 - V-248808 - SV-248808r779990_rule
RMF Control
AU-9
Severity
Medium
CCI
CCI-001493
Version
OL08-00-030630
Vuln IDs
  • V-248808
Rule IDs
  • SV-248808r779990_rule
Protecting audit information includes identifying and protecting the tools used to view and manipulate log data. Therefore, protecting audit tools is necessary to prevent unauthorized operation on audit information. OL 8 systems providing tools to interface with audit information will leverage user permissions and roles identifying the user accessing the tools, and the corresponding user rights, to make access decisions regarding the access to audit tools. Audit tools include but are not limited to vendor-provided and open source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators. Satisfies: SRG-OS-000256-GPOS-00097, SRG-OS-000257-GPOS-00098, SRG-OS-000258-GPOS-00099
Checks: C-52242r779988_chk

Verify the audit tools are owned by "root" to prevent any unauthorized access, deletion, or modification. Check the owner of each audit tool by running the following command: $ sudo stat -c "%U %n" /sbin/auditctl /sbin/aureport /sbin/ausearch /sbin/autrace /sbin/auditd /sbin/rsyslogd /sbin/augenrules root /sbin/auditctl root /sbin/aureport root /sbin/ausearch root /sbin/autrace root /sbin/auditd root /sbin/rsyslogd root /sbin/augenrules If any of the audit tools are not owned by "root", this is a finding.

Fix: F-52196r779989_fix

Configure the audit tools to be owned by "root" by running the following command: $ sudo chown root [audit_tool] Replace "[audit_tool]" with each audit tool not owned by "root".

b
OL 8 audit tools must be group-owned by root.
AU-9 - Medium - CCI-001493 - V-248809 - SV-248809r779993_rule
RMF Control
AU-9
Severity
Medium
CCI
CCI-001493
Version
OL08-00-030640
Vuln IDs
  • V-248809
Rule IDs
  • SV-248809r779993_rule
Protecting audit information also includes identifying and protecting the tools used to view and manipulate log data. Therefore, protecting audit tools is necessary to prevent unauthorized operation on audit information. OL 8 systems providing tools to interface with audit information will leverage user permissions and roles identifying the user accessing the tools, and the corresponding user rights, to make access decisions regarding the access to audit tools. Audit tools include but are not limited to vendor-provided and open source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators. Satisfies: SRG-OS-000256-GPOS-00097, SRG-OS-000257-GPOS-00098, SRG-OS-000258-GPOS-00099
Checks: C-52243r779991_chk

Verify the audit tools are group-owned by "root" to prevent any unauthorized access, deletion, or modification. Check the owner of each audit tool by running the following commands: $ sudo stat -c "%G %n" /sbin/auditctl /sbin/aureport /sbin/ausearch /sbin/autrace /sbin/auditd /sbin/rsyslogd /sbin/augenrules root /sbin/auditctl root /sbin/aureport root /sbin/ausearch root /sbin/autrace root /sbin/auditd root /sbin/rsyslogd root /sbin/augenrules If any of the audit tools are not group-owned by "root", this is a finding.

Fix: F-52197r779992_fix

Configure the audit tools to be group-owned by "root" by running the following command: $ sudo chgrp root [audit_tool] Replace "[audit_tool]" with each audit tool not group-owned by "root".

b
OL 8 must use cryptographic mechanisms to protect the integrity of audit tools.
AU-9 - Medium - CCI-001496 - V-248810 - SV-248810r880559_rule
RMF Control
AU-9
Severity
Medium
CCI
CCI-001496
Version
OL08-00-030650
Vuln IDs
  • V-248810
Rule IDs
  • SV-248810r880559_rule
Protecting the integrity of the tools used for auditing purposes is a critical step toward ensuring the integrity of audit information. Audit information includes all information (e.g., audit records, audit settings, and audit reports) needed to successfully audit information system activity. Audit tools include but are not limited to vendor-provided and open source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators. It is not uncommon for attackers to replace the audit tools or inject code into the existing tools to provide the capability to hide or erase system activity from the audit logs. To address this risk, audit tools must be cryptographically signed to provide the capability to identify when the audit tools have been modified, manipulated, or replaced. An example is a checksum hash of the file or files.
Checks: C-52244r880558_chk

Verify that Advanced Intrusion Detection Environment (AIDE) is properly configured to use cryptographic mechanisms to protect the integrity of audit tools. Check the selection lines to ensure AIDE is configured to add/check with the following command: $ sudo grep -E '(\/usr\/sbin\/(audit|au|rsys))' /etc/aide.conf /usr/sbin/auditctl p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/auditd p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/ausearch p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/aureport p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/autrace p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/rsyslogd p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/augenrules p+i+n+u+g+s+b+acl+xattrs+sha512 If any of the audit tools listed above do not have an appropriate selection line, this is a finding.

Fix: F-52198r833240_fix

Add or update the following lines to "/etc/aide.conf" to protect the integrity of the audit tools. # Audit Tools /usr/sbin/auditctl p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/auditd p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/ausearch p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/aureport p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/autrace p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/rsyslogd p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/augenrules p+i+n+u+g+s+b+acl+xattrs+sha512

b
OL 8 must allocate audit record storage capacity to store at least one week of audit records when audit records are not immediately sent to a central audit record storage facility.
AU-4 - Medium - CCI-001849 - V-248811 - SV-248811r877391_rule
RMF Control
AU-4
Severity
Medium
CCI
CCI-001849
Version
OL08-00-030660
Vuln IDs
  • V-248811
Rule IDs
  • SV-248811r877391_rule
To ensure OL 8 systems have a sufficient storage capacity in which to write the audit logs, OL 8 needs to be able to allocate audit record storage capacity. The task of allocating audit record storage capacity is usually performed during initial installation of OL 8.
Checks: C-52245r818685_chk

Verify OL 8 allocates audit record storage capacity to store at least one week of audit records when audit records are not immediately sent to a central audit record storage facility. Determine to which partition the audit records are being written with the following command: $ sudo grep -iw log_file /etc/audit/auditd.conf log_file = /var/log/audit/audit.log Check the size of the partition to which audit records are written (with the example being "/var/log/audit/") with the following command: $ sudo df -h /var/log/audit/ /dev/sda2 24G 10.4G 13.6G 43% /var/log/audit If the audit records are not written to a partition made specifically for audit records ("/var/log/audit" is a separate partition), determine the amount of space being used by other files in the partition with the following command: $ sudo du -sh [audit_partition] 1.8G /var/log/audit If the audit record partition is not allocated for sufficient storage capacity, this is a finding. Note: The partition size needed to capture a week of audit records is based on the activity level of the system and the total storage capacity available. Typically 10.0 GB of storage space for audit records should be sufficient.

Fix: F-52199r779998_fix

Allocate enough storage capacity for at least one week of audit records when audit records are not immediately sent to a central audit record storage facility. If audit records are stored on a partition made specifically for audit records, use the "X" program to resize the partition with sufficient space to contain one week of audit records. If audit records are not stored on a partition made specifically for audit records, a new partition with sufficient space will need be to be created.

b
OL 8 must have the packages required for offloading audit logs installed.
CM-6 - Medium - CCI-000366 - V-248812 - SV-248812r780002_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-030670
Vuln IDs
  • V-248812
Rule IDs
  • SV-248812r780002_rule
Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Offloading is a common process in information systems with limited audit storage capacity. OL 8 installation media provides "rsyslogd". This is a system utility providing support for message logging. Support for both internet and UNIX domain sockets enables this utility to support both local and remote logging. Coupling this utility with "gnutls" (which is a secure communications library implementing the SSL, TLS, and DTLS protocols) provides a method to securely encrypt and offload auditing. Rsyslog provides three ways to forward message: the traditional UDP transport, which is extremely lossy but standard; the plain TCP based transport, which loses messages only during certain situations but is widely available; and the RELP transport, which does not lose messages but is currently available only as part of the rsyslogd 3.15.0 and above. Examples of each configuration follow: UDP *.* @remotesystemname TCP *.* @@remotesystemname RELP *.* :omrelp:remotesystemname:2514 Note that a port number was given as there is no standard port for RELP.
Checks: C-52246r780000_chk

Verify the operating system has the packages required for offloading audit logs installed with the following commands: $ sudo yum list installed rsyslog rsyslog.x86_64 8.1911.0-3.el8 @AppStream If the "rsyslog" package is not installed, ask the administrator to indicate how audit logs are being offloaded and what packages are installed to support it. If there is no evidence of audit logs being offloaded, this is a finding.

Fix: F-52200r780001_fix

Configure the operating system to offload audit logs by installing the required packages with the following command: $ sudo yum install rsyslog

b
OL 8 must have the packages required for encrypting offloaded audit logs installed.
CM-6 - Medium - CCI-000366 - V-248813 - SV-248813r780005_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-030680
Vuln IDs
  • V-248813
Rule IDs
  • SV-248813r780005_rule
Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Offloading is a common process in information systems with limited audit storage capacity. OL 8 installation media provides "rsyslogd". This is a system utility providing support for message logging. Support for both internet and UNIX domain sockets enables this utility to support both local and remote logging. Coupling this utility with "gnutls" (which is a secure communications library implementing the SSL, TLS and DTLS protocols) provides a method to securely encrypt and offload auditing. Rsyslog provides three ways to forward message: the traditional UDP transport, which is extremely lossy but standard; the plain TCP based transport, which loses messages only during certain situations but is widely available; and the RELP transport, which does not lose messages but is currently available only as part of the rsyslogd 3.15.0 and above. Examples of each configuration follow: UDP *.* @remotesystemname TCP *.* @@remotesystemname RELP *.* :omrelp:remotesystemname:2514 Note that a port number was given as there is no standard port for RELP.
Checks: C-52247r780003_chk

Verify the operating system has the packages required for encrypting offloaded audit logs installed with the following commands: $ sudo yum list installed rsyslog-gnutls rsyslog-gnutls.x86_64 8.1911.0-6.el8 @AppStream If the "rsyslog-gnutls" package is not installed, ask the administrator to indicate how audit logs are being encrypted during offloading and what packages are installed to support it. If there is no evidence of audit logs being encrypted during offloading, this is a finding.

Fix: F-52201r780004_fix

Configure the operating system to encrypt offloaded audit logs by installing the required packages with the following command: $ sudo yum install rsyslog-gnutls

b
The OL 8 audit records must be offloaded onto a different system or storage media from the system being audited.
AU-4 - Medium - CCI-001851 - V-248814 - SV-248814r917914_rule
RMF Control
AU-4
Severity
Medium
CCI
CCI-001851
Version
OL08-00-030690
Vuln IDs
  • V-248814
Rule IDs
  • SV-248814r917914_rule
Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Offloading is a common process in information systems with limited audit storage capacity. OL 8 installation media provides "rsyslogd". This is a system utility providing support for message logging. Support for both internet and UNIX domain sockets enables this utility to support both local and remote logging. Coupling this utility with "gnutls" (which is a secure communications library implementing the SSL, TLS and DTLS protocols) provides a method to securely encrypt and offload auditing. Rsyslog provides three ways to forward message: the traditional UDP transport, which is extremely lossy but standard; the plain TCP based transport, which loses messages only during certain situations but is widely available; and the RELP transport, which does not lose messages but is currently available only as part of the rsyslogd 3.15.0 and above. Examples of each configuration follow: UDP *.* @remotesystemname TCP *.* @@remotesystemname RELP *.* :omrelp:remotesystemname:2514 Note that a port number was given as there is no standard port for RELP. Satisfies: SRG-OS-000342-GPOS-00133, SRG-OS-000479-GPOS-00224
Checks: C-52248r917912_chk

Verify the audit system offloads audit records onto a different system or media from the system being audited with the following command: $ sudo grep @@ /etc/rsyslog.conf /etc/rsyslog.d/*.conf /etc/rsyslog.conf:*.* @@[logaggregationserver.example.mil]:[port] If a remote server is not configured or the line is commented out, ask the system administrator to indicate how the audit logs are offloaded to a different system or media. If there is no evidence that the audit logs are being offloaded to another system or media, this is a finding.

Fix: F-52202r917913_fix

Configure OL 8 to offload audit records onto a different system or media from the system being audited by specifying the remote logging server in "/etc/rsyslog.conf" or "/etc/rsyslog.d/[customfile].conf" with the name or IP address of the log aggregation server. For UDP: *.* @[logaggregationserver.example.mil]:[port] For TCP: *.* @@[logaggregationserver.example.mil]:[port]

b
OL 8 must take appropriate action when the internal event queue is full.
AU-4 - Medium - CCI-001851 - V-248815 - SV-248815r877390_rule
RMF Control
AU-4
Severity
Medium
CCI
CCI-001851
Version
OL08-00-030700
Vuln IDs
  • V-248815
Rule IDs
  • SV-248815r877390_rule
Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Offloading is a common process in information systems with limited audit storage capacity. OL 8 installation media provides "rsyslogd". This is a system utility providing support for message logging. Support for both internet and UNIX domain sockets enables this utility to support both local and remote logging. Coupling this utility with "gnutls" (which is a secure communications library implementing the SSL, TLS and DTLS protocols) provides a method to securely encrypt and offload auditing. Satisfies: SRG-OS-000342-GPOS-00133, SRG-OS-000479-GPOS-00224
Checks: C-52249r780009_chk

Verify the audit system is configured to take an appropriate action when the internal event queue is full: $ sudo grep -i overflow_action /etc/audit/auditd.conf overflow_action = syslog If the value of the "overflow_action" option is not set to "syslog", "single", or "halt", or the line is commented out, ask the System Administrator to indicate how the audit logs are offloaded to a different system or media. If there is no evidence that the transfer of the audit logs being offloaded to another system or media takes appropriate action if the internal event queue becomes full, this is a finding.

Fix: F-52203r780010_fix

Edit the "/etc/audit/auditd.conf" file and add or update the "overflow_action" option: overflow_action = syslog The audit daemon must be restarted for changes to take effect.

b
OL 8 must encrypt the transfer of audit records offloaded onto a different system or media from the system being audited.
AU-4 - Medium - CCI-001851 - V-248816 - SV-248816r877390_rule
RMF Control
AU-4
Severity
Medium
CCI
CCI-001851
Version
OL08-00-030710
Vuln IDs
  • V-248816
Rule IDs
  • SV-248816r877390_rule
Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Offloading is a common process in information systems with limited audit storage capacity. OL 8 installation media provides "rsyslogd". This is a system utility providing support for message logging. Support for both internet and UNIX domain sockets enables this utility to support both local and remote logging. Coupling this utility with "gnutls" (which is a secure communications library implementing the SSL, TLS, and DTLS protocols) provides a method to securely encrypt and offload auditing. Satisfies: SRG-OS-000342-GPOS-00133, SRG-OS-000479-GPOS-00224
Checks: C-52250r818687_chk

Verify the operating system encrypts audit records offloaded onto a different system or media from the system being audited with the following commands: $ sudo grep -i '$DefaultNetstreamDriver' /etc/rsyslog.conf /etc/rsyslog.d/*.conf /etc/rsyslog.conf:$DefaultNetstreamDriver gtls If the value of the "$DefaultNetstreamDriver" option is not set to "gtls" or the line is commented out, this is a finding. $ sudo grep -i '$ActionSendStreamDriverMode' /etc/rsyslog.conf /etc/rsyslog.d/*.conf /etc/rsyslog.conf:$ActionSendStreamDriverMode 1 If the value of the "$ActionSendStreamDriverMode" option is not set to "1" or the line is commented out, this is a finding. If neither of the definitions above are set, ask the System Administrator to indicate how the audit logs are offloaded to a different system or media. If there is no evidence that the transfer of the audit logs being offloaded to another system or media is encrypted, this is a finding.

Fix: F-52204r780013_fix

Configure the operating system to encrypt offloaded audit records by setting the following options in "/etc/rsyslog.conf" or "/etc/rsyslog.d/[customfile].conf": $DefaultNetstreamDriver gtls $ActionSendStreamDriverMode 1

b
OL 8 must authenticate the remote logging server for offloading audit logs.
AU-4 - Medium - CCI-001851 - V-248817 - SV-248817r877390_rule
RMF Control
AU-4
Severity
Medium
CCI
CCI-001851
Version
OL08-00-030720
Vuln IDs
  • V-248817
Rule IDs
  • SV-248817r877390_rule
Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Offloading is a common process in information systems with limited audit storage capacity. OL 8 installation media provides "rsyslogd". This is a system utility providing support for message logging. Support for both internet and UNIX domain sockets enables this utility to support both local and remote logging. Coupling this utility with "gnutls" (which is a secure communications library implementing the SSL, TLS and DTLS protocols) provides a method to securely encrypt and offload auditing. "Rsyslog" supported authentication modes include the following: anon - anonymous authentication x509/fingerprint - certificate fingerprint authentication x509/certvalid - certificate validation only x509/name - certificate validation and subject name authentication Satisfies: SRG-OS-000342-GPOS-00133, SRG-OS-000479-GPOS-00224
Checks: C-52251r780015_chk

Verify the operating system authenticates the remote logging server for offloading audit logs with the following command: $ sudo grep -i '$ActionSendStreamDriverAuthMode' /etc/rsyslog.conf /etc/rsyslog.d/*.conf /etc/rsyslog.conf:$ActionSendStreamDriverAuthMode x509/name If the value of the "$ActionSendStreamDriverAuthMode" option is not set to "x509/name" or the line is commented out, ask the System Administrator to indicate how the audit logs are offloaded to a different system or media. If there is no evidence that the transfer of the audit logs being offloaded to another system or media is encrypted, this is a finding.

Fix: F-52205r780016_fix

Configure the operating system to authenticate the remote logging server for offloading audit logs by setting the following option in "/etc/rsyslog.conf" or "/etc/rsyslog.d/[customfile].conf": $ActionSendStreamDriverAuthMode x509/name

b
OL 8 must take action when allocated audit record storage volume reaches 75 percent of the repository maximum audit record storage capacity.
AU-5 - Medium - CCI-001855 - V-248818 - SV-248818r877389_rule
RMF Control
AU-5
Severity
Medium
CCI
CCI-001855
Version
OL08-00-030730
Vuln IDs
  • V-248818
Rule IDs
  • SV-248818r877389_rule
If security personnel are not notified immediately when storage volume reaches 75 percent utilization, they are unable to plan for audit record storage capacity expansion.
Checks: C-52252r780018_chk

Verify OL 8 takes action when allocated audit record storage volume reaches 75 percent of the repository maximum audit record storage capacity with the following commands: $ sudo grep -w space_left /etc/audit/auditd.conf space_left = 25% If the value of the "space_left" keyword is not set to "25%" or if the line is commented out, ask the SA to demonstrate how the system is providing real-time alerts to the SA and ISSO. If there is no evidence that real-time alerts are configured on the system, this is a finding.

Fix: F-52206r780019_fix

Configure OL 8 to initiate an action to notify the SA and ISSO (at a minimum) when allocated audit record storage volume reaches 75 percent of the repository maximum audit record storage capacity by adding/modifying the following line in the "/etc/audit/auditd.conf" file. space_left = 25%

b
OL 8 must notify the System Administrator (SA) and Information System Security Officer (ISSO) (at a minimum) when allocated audit record storage volume 75 percent utilization.
AU-5 - Medium - CCI-001855 - V-248819 - SV-248819r877389_rule
RMF Control
AU-5
Severity
Medium
CCI
CCI-001855
Version
OL08-00-030731
Vuln IDs
  • V-248819
Rule IDs
  • SV-248819r877389_rule
If security personnel are not notified immediately when storage volume reaches 75 percent utilization, they are unable to plan for audit record storage capacity expansion.
Checks: C-52253r780021_chk

Verify OL 8 notifies the SA and ISSO (at a minimum) when allocated audit record storage volume reaches 75 percent of the repository maximum audit record storage capacity with the following command: $ sudo grep -w space_left_action /etc/audit/auditd.conf space_left_action = email If the value of the "space_left_action" is not set to "email", or if the line is commented out, ask the System Administrator to indicate how the system is providing real-time alerts to the SA and ISSO. If there is no evidence that real-time alerts are configured on the system, this is a finding.

Fix: F-52207r780022_fix

Configure the operating system to initiate an action to notify the SA and ISSO (at a minimum) when allocated audit record storage volume reaches 75 percent of the repository maximum audit record storage capacity by adding/modifying the following line in the /etc/audit/auditd.conf file. space_left_action = email Note: Option names and values in the auditd.conf file are case insensitive.

b
OL 8 must compare internal information system clocks at least every 24 hours with a server synchronized to an authoritative time source, such as the United States Naval Observatory (USNO) time servers, or a time server designated for the appropriate DoD network (NIPRNet/SIPRNet), and/or the Global Positioning System (GPS).
AU-8 - Medium - CCI-001890 - V-248820 - SV-248820r877038_rule
RMF Control
AU-8
Severity
Medium
CCI
CCI-001890
Version
OL08-00-030740
Vuln IDs
  • V-248820
Rule IDs
  • SV-248820r877038_rule
Inaccurate time stamps make it more difficult to correlate events and can lead to an inaccurate analysis. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. Sources outside the configured acceptable allowance (drift) may be inaccurate. Synchronizing internal information system clocks provides uniformity of time stamps for information systems with multiple system clocks and systems connected over a network. Organizations should consider endpoints that may not have regular access to the authoritative time server (e.g., mobile, teleworking, and tactical endpoints). If time stamps are not consistently applied and there is no common time reference, it is difficult to perform forensic analysis. Time stamps generated by the operating system include date and time. Time is commonly expressed in Coordinated Universal Time (UTC), a modern continuation of Greenwich Mean Time (GMT), or local time with an offset from UTC. OL 8 uses the "timedatectl" command to view the status of the "systemd-timesyncd.service". The "timedatectl" status will display the local time, UTC, and the offset from UTC. Note that USNO offers authenticated NTP service to DoD and U.S. Government agencies operating on the NIPR and SIPR networks. Visit https://www.usno.navy.mil/USNO/time/ntp/dod-customers for more information. Satisfies: SRG-OS-000355-GPOS-00143, SRG-OS-000356-GPOS-00144, SRG-OS-000359-GPOS-00146
Checks: C-52254r780024_chk

Verify OL 8 is comparing internal information system clocks at least every 24 hours with an NTP server with the following command: $ sudo grep maxpoll /etc/chrony.conf server [ntp.server.name] iburst maxpoll 16 If the "maxpoll" option is set to a number greater than "16" or the line is commented out, this is a finding.

Fix: F-52208r780025_fix

Configure OL 8 to compare internal information system clocks at least every 24 hours with an NTP server by adding/modifying the following line in the "/etc/chrony.conf" file. server [ntp.server.name] iburst maxpoll 16

a
OL 8 must disable the chrony daemon from acting as a server.
CM-7 - Low - CCI-000381 - V-248821 - SV-248821r928556_rule
RMF Control
CM-7
Severity
Low
CCI
CCI-000381
Version
OL08-00-030741
Vuln IDs
  • V-248821
Rule IDs
  • SV-248821r928556_rule
Inaccurate time stamps make it more difficult to correlate events and can lead to an inaccurate analysis. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. Sources outside the configured acceptable allowance (drift) may be inaccurate. Minimizing the exposure of the server functionality of the chrony daemon diminishes the attack surface. Note that USNO offers authenticated NTP service to DOD and U.S. Government agencies operating on the NIPR and SIPR networks. Visit https://www.usno.navy.mil/USNO/time/ntp/DOD-customers for more information.
Checks: C-52255r928554_chk

Note: If the system is approved and documented by the information system security officer (ISSO) to function as an NTP time server, this requirement is Not Applicable. Verify OL 8 disables the chrony daemon from acting as a server with the following command: $ sudo grep -w 'port' /etc/chrony.conf port 0 If the "port" option is not set to "0" or is commented out or missing, this is a finding.

Fix: F-52209r928555_fix

Configure OL 8 to disable the chrony daemon from acting as a server by adding or modifying the following line in the "/etc/chrony.conf" file. port 0

a
OL 8 must disable network management of the chrony daemon.
CM-7 - Low - CCI-000381 - V-248822 - SV-248822r928559_rule
RMF Control
CM-7
Severity
Low
CCI
CCI-000381
Version
OL08-00-030742
Vuln IDs
  • V-248822
Rule IDs
  • SV-248822r928559_rule
Inaccurate time stamps make it more difficult to correlate events and can lead to an inaccurate analysis. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. Sources outside the configured acceptable allowance (drift) may be inaccurate. Minimizing the exposure of the server functionality of the chrony daemon diminishes the attack surface. Note that USNO offers authenticated NTP service to DOD and U.S. Government agencies operating on the NIPR and SIPR networks. Visit https://www.usno.navy.mil/USNO/time/ntp/DOD-customers for more information.
Checks: C-52256r928557_chk

Note: If the system is approved and documented by the information system security officer (ISSO) to function as an NTP time server, this requirement is Not Applicable. Verify OL 8 disables network management of the chrony daemon with the following command: $ sudo grep -w 'cmdport' /etc/chrony.conf cmdport 0 If the "cmdport" option is not set to "0" or is commented out or missing, this is a finding.

Fix: F-52210r928558_fix

Configure OL 8 to disable network management of the chrony daemon by adding or modifying the following line in the "/etc/chrony.conf" file. cmdport 0

c
OL 8 must not have the telnet-server package installed.
CM-7 - High - CCI-000381 - V-248823 - SV-248823r780035_rule
RMF Control
CM-7
Severity
High
CCI
CCI-000381
Version
OL08-00-040000
Vuln IDs
  • V-248823
Rule IDs
  • SV-248823r780035_rule
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Operating systems are capable of providing a wide variety of functions and services. Some of the functions and services, provided by default, may not be necessary to support essential organizational operations (e.g., key missions, functions). Examples of non-essential capabilities include but are not limited to games, software packages, tools, and demonstration software not related to requirements or providing a wide array of functionality not required for every mission, but which cannot be disabled. Verify the operating system is configured to disable non-essential capabilities. The most secure way of ensuring a non-essential capability is disabled is to not have the capability installed. The telnet service provides an unencrypted remote access service that does not provide for the confidentiality and integrity of user passwords or the remote session. If a privileged user were to log on using this service, the privileged user password could be compromised.
Checks: C-52257r780033_chk

Determine if the telnet-server package is installed with the following command: $ sudo yum list installed telnet-server If the telnet-server package is installed, this is a finding.

Fix: F-52211r780034_fix

Configure OL 8 to disable non-essential capabilities by removing the telnet-server package from the system with the following command: $ sudo yum remove telnet-server

b
OL 8 must not have any automated bug reporting tools installed.
CM-7 - Medium - CCI-000381 - V-248824 - SV-248824r780038_rule
RMF Control
CM-7
Severity
Medium
CCI
CCI-000381
Version
OL08-00-040001
Vuln IDs
  • V-248824
Rule IDs
  • SV-248824r780038_rule
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Operating systems are capable of providing a wide variety of functions and services. Some of the functions and services, provided by default, may not be necessary to support essential organizational operations (e.g., key missions, functions). Examples of non-essential capabilities include but are not limited to games, software packages, tools, and demonstration software not related to requirements or providing a wide array of functionality not required for every mission, but which cannot be disabled. Verify the operating system is configured to disable non-essential capabilities. The most secure way of ensuring a non-essential capability is disabled is to not have the capability installed.
Checks: C-52258r780036_chk

Determine if any automated bug reporting packages are installed with the following command: $ sudo yum list installed abrt* If any automated bug reporting package is installed, this is a finding.

Fix: F-52212r780037_fix

Configure the operating system to disable non-essential capabilities by removing automated bug reporting packages from the system with the following command: $ sudo yum remove abrt*

b
OL 8 must not have the sendmail package installed.
CM-7 - Medium - CCI-000381 - V-248825 - SV-248825r780041_rule
RMF Control
CM-7
Severity
Medium
CCI
CCI-000381
Version
OL08-00-040002
Vuln IDs
  • V-248825
Rule IDs
  • SV-248825r780041_rule
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Operating systems are capable of providing a wide variety of functions and services. Some of the functions and services, provided by default, may not be necessary to support essential organizational operations (e.g., key missions, functions). Examples of non-essential capabilities include but are not limited to games, software packages, tools, and demonstration software not related to requirements or providing a wide array of functionality not required for every mission, but which cannot be disabled. Verify the operating system is configured to disable non-essential capabilities. The most secure way of ensuring a non-essential capability is disabled is to not have the capability installed.
Checks: C-52259r780039_chk

Determine if the sendmail package is installed with the following command: $ sudo yum list installed sendmail If the sendmail package is installed, this is a finding.

Fix: F-52213r780040_fix

Configure the operating system to disable non-essential capabilities by removing the sendmail package from the system with the following command: $ sudo yum remove sendmail

a
OL 8 must enable mitigations against processor-based vulnerabilities.
CM-7 - Low - CCI-000381 - V-248826 - SV-248826r780044_rule
RMF Control
CM-7
Severity
Low
CCI
CCI-000381
Version
OL08-00-040004
Vuln IDs
  • V-248826
Rule IDs
  • SV-248826r780044_rule
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Operating systems are capable of providing a wide variety of functions and services. Some of the functions and services, provided by default, may not be necessary to support essential organizational operations (e.g., key missions, functions). Examples of non-essential capabilities include, but are not limited to, games, software packages, tools, and demonstration software not related to requirements or providing a wide array of functionality not required for every mission, but which cannot be disabled. Verify the operating system is configured to disable non-essential capabilities. The most secure way of ensuring a non-essential capability is disabled is to not have the capability installed. Kernel page-table isolation is a kernel feature that mitigates the Meltdown security vulnerability and hardens the kernel against attempts to bypass kernel address space layout randomization (KASLR).
Checks: C-52260r780042_chk

Verify OL 8 enables kernel page-table isolation with the following commands: $ sudo grub2-editenv list | grep pti kernelopts=root=/dev/mapper/ol-root ro crashkernel=auto resume=/dev/mapper/ol-swap rd.lvm.lv=ol/root rd.lvm.lv=ol/swap rhgb quiet fips=1 audit=1 audit_backlog_limit=8192 pti=on boot=UUID=8d171156-cd61-421c-ba41-1c021ac29e82 If the "pti" entry does not equal "on", is missing, or the line is commented out, this is a finding. Check that kernel page-table isolation is enabled by default to persist in kernel updates: $ sudo grep pti /etc/default/grub GRUB_CMDLINE_LINUX="pti=on" If "pti" is not set to "on", is missing or commented out, this is a finding.

Fix: F-52214r780043_fix

Configure OL 8 to enable kernel page-table isolation with the following command: $ sudo grubby --update-kernel=ALL --args="pti=on" Add or modify the following line in "/etc/default/grub" to ensure the configuration survives kernel updates: GRUB_CMDLINE_LINUX="pti=on"

c
OL 8 must not have the rsh-server package installed.
CM-7 - High - CCI-000381 - V-248827 - SV-248827r780047_rule
RMF Control
CM-7
Severity
High
CCI
CCI-000381
Version
OL08-00-040010
Vuln IDs
  • V-248827
Rule IDs
  • SV-248827r780047_rule
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Operating systems are capable of providing a wide variety of functions and services. Some of the functions and services, provided by default, may not be necessary to support essential organizational operations (e.g., key missions, functions). The rsh-server service provides an unencrypted remote access service that does not provide for the confidentiality and integrity of user passwords or the remote session and has very weak authentication. If a privileged user were to log on using this service, the privileged user password could be compromised.
Checks: C-52261r780045_chk

Determine if the rsh-server package is installed with the following command: $ sudo yum list installed rsh-server If the rsh-server package is installed, this is a finding.

Fix: F-52215r780046_fix

Configure the operating system to disable non-essential capabilities by removing the rsh-server package from the system with the following command: $ sudo yum remove rsh-server

b
OL 8 must cover or disable the built-in or attached camera when not in use.
CM-7 - Medium - CCI-000381 - V-248828 - SV-248828r943068_rule
RMF Control
CM-7
Severity
Medium
CCI
CCI-000381
Version
OL08-00-040020
Vuln IDs
  • V-248828
Rule IDs
  • SV-248828r943068_rule
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Failing to disconnect from collaborative computing devices (i.e., cameras) can result in subsequent compromises of organizational information. Providing easy methods to physically disconnect from such devices after a collaborative computing session helps to ensure participants actually carry out the disconnect activity without having to go through complex and tedious procedures.
Checks: C-52262r943066_chk

If the device or operating system does not have a camera installed, this requirement is not applicable. This requirement is not applicable to mobile devices (smartphones and tablets), where the use of the camera is a local AO decision. This requirement is not applicable to dedicated VTC suites located in approved VTC locations that are centrally managed. For an external camera, if there is not a method for the operator to manually disconnect the camera at the end of collaborative computing sessions, this is a finding. For a built-in camera, the camera must be protected by a camera cover (e.g., laptop camera cover slide) when not in use. If the built-in camera is not protected with a camera cover or is not physically disabled, this is a finding. If the camera is not disconnected, covered, or physically disabled, determine if it is being disabled via software with the following commands: Verify the operating system disables the ability to load the uvcvideo kernel module. $ sudo grep -r uvcvideo /etc/modprobe.d/* | grep "/bin/false" install uvcvideo /bin/false If the command does not return any output, or the line is commented out, and the collaborative computing device has not been authorized for use, this is a finding. Verify the camera is disabled via blacklist with the following command: $ sudo grep -r uvcvideo /etc/modprobe.d/* | grep "blacklist" blacklist uvcvideo If the command does not return any output or the output is not "blacklist uvcvideo", and the collaborative computing device has not been authorized for use, this is a finding.

Fix: F-52216r943067_fix

Configure OL 8 to disable the built-in or attached camera when not in use. Build or modify the "/etc/modprobe.d/blacklist.conf" file by using the following example: install uvcvideo /bin/false blacklist uvcvideo Reboot the system for the settings to take effect.

b
OL 8 must not have the asynchronous transfer mode (ATM) kernel module installed if not required for operational support.
CM-6 - Medium - CCI-000366 - V-248829 - SV-248829r943071_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040021
Vuln IDs
  • V-248829
Rule IDs
  • SV-248829r943071_rule
The ATM is a transport layer protocol designed for digital transmission of multiple types of traffic, including telephony (voice), data, and video signals, in one network without the use of separate overlay networks. Disabling ATM protects the system against exploitation of any flaws in its implementation.
Checks: C-52263r943069_chk

Verify the operating system disables the ability to load the "atm" kernel module. $ sudo grep -r atm /etc/modprobe.d/* | grep -i "/bin/false" | grep -v "^#" install atm /bin/false If the command does not return any output or the line is commented out, and use of ATM is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding. Verify the operating system disables the ability to use ATM with the following command: $ sudo grep atm /etc/modprobe.d/* | grep -i "blacklist" | grep -v "^#" blacklist atm If the command does not return any output or the output is not "blacklist atm", and use of ATM is not documented with the ISSO as an operational requirement, this is a finding.

Fix: F-52217r943070_fix

Configure OL 8 to disable the ability to use the "atm" kernel module. Create a file under "/etc/modprobe.d" with the following command: $ sudo touch /etc/modprobe.d/atm.conf Add the following line to the created file: install atm /bin/false Configure OL 8 to disable the ability to use the atm kernel module. $ sudo vi /etc/modprobe.d/blacklist.conf Add or update the line: blacklist atm

b
OL 8 must not have the Controller Area Network (CAN) kernel module installed if not required for operational support.
CM-6 - Medium - CCI-000366 - V-248830 - SV-248830r943074_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040022
Vuln IDs
  • V-248830
Rule IDs
  • SV-248830r943074_rule
The CAN protocol is a robust vehicle bus standard designed to allow microcontrollers and devices to communicate with each other's applications without a host computer. Disabling CAN protects the system against exploitation of any flaws in its implementation.
Checks: C-52264r943072_chk

Verify the operating system disables the ability to load the "can" kernel module. $ sudo grep -r can /etc/modprobe.d/* | grep -i "/bin/false" | grep -v "^#" install can /bin/false If the command does not return any output or the line is commented out, and use of "can" is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding. Verify the operating system disables the ability to use CAN with the following command: $ sudo grep can /etc/modprobe.d/* | grep -i "blacklist" | grep -v "^#" blacklist can If the command does not return any output or the output is not "blacklist can", and use of CAN is not documented with the ISSO as an operational requirement, this is a finding.

Fix: F-52218r943073_fix

Configure OL 8 to disable the ability to use the "can" kernel module. Create a file under "/etc/modprobe.d" with the following command: $ sudo touch /etc/modprobe.d/can.conf Add the following line to the created file: install can /bin/false Configure OL 8 to disable the ability to use the can kernel module. $ sudo vi /etc/modprobe.d/blacklist.conf Add or update the line: blacklist can

b
OL 8 must not have the stream control transmission protocol (SCTP) kernel module installed if not required for operational support.
CM-6 - Medium - CCI-000366 - V-248831 - SV-248831r943077_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040023
Vuln IDs
  • V-248831
Rule IDs
  • SV-248831r943077_rule
The SCTP is a transport layer protocol, designed to support the idea of message-oriented communication, with several streams of messages within one connection. Disabling SCTP protects the system against exploitation of any flaws in its implementation.
Checks: C-52265r943075_chk

Verify the operating system disables the ability to load the "sctp" kernel module. $ sudo grep -r sctp /etc/modprobe.d/* | grep -i "/bin/false" | grep -v "^#" install sctp /bin/false If the command does not return any output or the line is commented out, and use of SCTP is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding. Verify the operating system disables the ability to use SCTP with the following command: $ sudo grep sctp /etc/modprobe.d/* | grep -i "blacklist" | grep -v "^#" blacklist sctp If the command does not return any output or the output is not "blacklist sctp", and use of SCTP is not documented with the ISSO as an operational requirement, this is a finding.

Fix: F-52219r943076_fix

Configure OL 8 to disable the ability to use the "sctp" kernel module. Create a file under "/etc/modprobe.d" with the following command: $ sudo touch /etc/modprobe.d/sctp.conf Add the following line to the created file: install sctp /bin/false Configure OL 8 to disable the ability to use the sctp kernel module. $ sudo vi /etc/modprobe.d/blacklist.conf Add or update the line: blacklist sctp

a
OL 8 must disable the transparent inter-process communication (TIPC) protocol.
CM-7 - Low - CCI-000381 - V-248832 - SV-248832r943080_rule
RMF Control
CM-7
Severity
Low
CCI
CCI-000381
Version
OL08-00-040024
Vuln IDs
  • V-248832
Rule IDs
  • SV-248832r943080_rule
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Failing to disconnect unused protocols can result in a system compromise. The Transparent Inter-Process Communication (TIPC) protocol is designed to provide communications between nodes in a cluster. Disabling TIPC protects the system against exploitation of any flaws in its implementation.
Checks: C-52266r943078_chk

Verify the operating system disables the ability to load the TIPC protocol kernel module. $ sudo grep -r tipc /etc/modprobe.d/* | grep "/bin/false" install tipc /bin/false If the command does not return any output, or the line is commented out, and use of the TIPC protocol is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding. Verify the operating system disables the ability to use the TIPC protocol. Determine if the TIPC protocol is disabled with the following command: $ sudo grep -r tipc /etc/modprobe.d/* | grep "blacklist" blacklist tipc If the command does not return any output or the output is not "blacklist tipc", and use of the TIPC protocol is not documented with the ISSO as an operational requirement, this is a finding.

Fix: F-52220r943079_fix

Configure the operating system to disable the ability to use the TIPC protocol kernel module. Add or update the following lines in the file "/etc/modprobe.d/blacklist.conf": install tipc /bin/false blacklist tipc Reboot the system for the settings to take effect.

a
OL 8 must disable mounting of cramfs.
CM-7 - Low - CCI-000381 - V-248833 - SV-248833r943083_rule
RMF Control
CM-7
Severity
Low
CCI
CCI-000381
Version
OL08-00-040025
Vuln IDs
  • V-248833
Rule IDs
  • SV-248833r943083_rule
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Removing support for unneeded filesystem types reduces the local attack surface of the server. Compressed ROM/RAM file system (or cramfs) is a read-only file system designed for simplicity and space-efficiency. It is mainly used in embedded and small-footprint systems.
Checks: C-52267r943081_chk

Verify the operating system disables the ability to load the cramfs kernel module. $ sudo grep -ri cramfs /etc/modprobe.d/* | grep -i "/bin/false" install cramfs /bin/false If the command does not return any output, or the line is commented out, and use of the cramfs protocol is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding. Verify the operating system disables the ability to use the cramfs kernel module. Determine if the cramfs kernel module is disabled with the following command: $ sudo grep -ri cramfs /etc/modprobe.d/* | grep -i "blacklist" blacklist cramfs If the command does not return any output or the output is not "blacklist cramfs", and use of the cramfs kernel module is not documented with the ISSO as an operational requirement, this is a finding.

Fix: F-52221r943082_fix

Configure the operating system to disable the ability to use the cramfs kernel module. Add or update the following lines in the file "/etc/modprobe.d/blacklist.conf": install cramfs /bin/false blacklist cramfs Reboot the system for the settings to take effect.

a
OL 8 must disable IEEE 1394 (FireWire) Support.
CM-7 - Low - CCI-000381 - V-248834 - SV-248834r943086_rule
RMF Control
CM-7
Severity
Low
CCI
CCI-000381
Version
OL08-00-040026
Vuln IDs
  • V-248834
Rule IDs
  • SV-248834r943086_rule
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. The IEEE 1394 (FireWire) is a serial bus standard for high-speed real-time communication. Disabling FireWire protects the system against exploitation of any flaws in its implementation.
Checks: C-52268r943084_chk

Verify the operating system disables the ability to load the firewire-core kernel module. $ sudo grep -ri firewire-core /etc/modprobe.d/* | grep -i "/bin/false" install firewire-core /bin/false If the command does not return any output, or the line is commented out, and use of the firewire-core protocol is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding. Verify the operating system disables the ability to use the firewire-core kernel module. Determine if the firewire-core kernel module is disabled with the following command: $ sudo grep -ri firewire-core /etc/modprobe.d/* | grep -i "blacklist" blacklist firewire-core If the command does not return any output or the output is not "blacklist firewire-core", and use of the firewire-core kernel module is not documented with the ISSO as an operational requirement, this is a finding.

Fix: F-52222r943085_fix

Configure the operating system to disable the ability to use the firewire-core kernel module. Add or update the following lines in the file "/etc/modprobe.d/blacklist.conf": install firewire-core /bin/false blacklist firewire-core Reboot the system for the settings to take effect.

b
OL 8 must be configured to prohibit or restrict the use of functions, ports, protocols, and/or services as defined in the Ports, Protocols, and Services Management (PPSM) Category Assignments List (CAL) and vulnerability assessments.
CM-7 - Medium - CCI-000382 - V-248835 - SV-248835r780071_rule
RMF Control
CM-7
Severity
Medium
CCI
CCI-000382
Version
OL08-00-040030
Vuln IDs
  • V-248835
Rule IDs
  • SV-248835r780071_rule
To prevent unauthorized connection of devices, unauthorized transfer of information, or unauthorized tunneling (i.e., embedding of data types within data types), organizations must disable or restrict unused or unnecessary physical and logical ports/protocols on information systems. Operating systems are capable of providing a wide variety of functions and services. Some of the functions and services provided by default may not be necessary to support essential organizational operations. Additionally, it is sometimes convenient to provide multiple services from a single component (e.g., VPN and IPS); however, doing so increases risk over limiting the services provided by any one component. To support the requirements and principles of least functionality, the operating system must support the organizational requirements, providing only essential capabilities and limiting the use of ports, protocols, and/or services to only those required, authorized, and approved to conduct official business or to address authorized quality-of-life issues.
Checks: C-52269r780069_chk

Inspect the firewall configuration and running services to verify it is configured to prohibit or restrict the use of functions, ports, protocols, and/or services that are unnecessary or prohibited. Check which services are currently active with the following command: $ sudo firewall-cmd --list-all custom (active) target: DROP icmp-block-inversion: no interfaces: ens33 sources: services: dhcpv6-client dns http https ldaps rpc-bind ssh ports: masquerade: no forward-ports: icmp-blocks: rich rules: Ask the System Administrator for the site or program PPSM Component Local Service Assessment (CLSA). Verify the services allowed by the firewall match the PPSM CLSA. If there are additional ports, protocols, or services that are not in the PPSM CLSA, or there are ports, protocols, or services that are prohibited by the PPSM CAL, this is a finding.

Fix: F-52223r780070_fix

Update the host's firewall settings and/or running services to comply with the PPSM CLSA for the site or program and the PPSM CAL.

b
The OL 8 file system automounter must be disabled unless required.
IA-3 - Medium - CCI-000778 - V-248836 - SV-248836r780074_rule
RMF Control
IA-3
Severity
Medium
CCI
CCI-000778
Version
OL08-00-040070
Vuln IDs
  • V-248836
Rule IDs
  • SV-248836r780074_rule
Verify the operating system disables the ability to automount devices. Determine if automounter service is active with the following command: $ sudo systemctl status autofs autofs.service - Automounts filesystems on demand Loaded: loaded (/usr/lib/systemd/system/autofs.service; disabled) Active: inactive (dead) If the "autofs" status is set to "active" and is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding.
Checks: C-52270r780072_chk

Verify the operating system disables the ability to automount devices. Determine if the automounter service is active with the following command: $ sudo systemctl status autofs autofs.service - Automounts filesystems on demand Loaded: loaded (/usr/lib/systemd/system/autofs.service; disabled) Active: inactive (dead) If the "autofs" status is set to "active" and is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding.

Fix: F-52224r780073_fix

Configure OL 8 to disable the ability to automount devices. Turn off the automount service with the following commands: $ sudo systemctl stop autofs $ sudo systemctl disable autofs If "autofs" is required for Network File System (NFS), it must be documented with the ISSO.

b
OL 8 must be configured to disable the ability to use USB mass storage devices.
IA-3 - Medium - CCI-000778 - V-248837 - SV-248837r943089_rule
RMF Control
IA-3
Severity
Medium
CCI
CCI-000778
Version
OL08-00-040080
Vuln IDs
  • V-248837
Rule IDs
  • SV-248837r943089_rule
USB mass storage permits easy introduction of unknown devices, thereby facilitating malicious activity.
Checks: C-52271r943087_chk

Verify the operating system disables the ability to load the USB Storage kernel module. $ sudo grep -r usb-storage /etc/modprobe.d/* | grep -i "/bin/false" install usb-storage /bin/false If the command does not return any output, or the line is commented out, and use of USB Storage is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding. Determine if USB mass storage is disabled with the following command: $ sudo grep usb-storage /etc/modprobe.d/* | grep -i "blacklist" | grep -v "^#" /etc/modprobe.d/blacklist.conf:blacklist usb-storage If the command does not return any output or the output is not "blacklist usb-storage" and use of USB storage devices is not documented with the ISSO as an operational requirement, this is a finding.

Fix: F-52225r943088_fix

Configure OL 8 to disable the ability to use the USB Storage kernel module and to use USB mass storage devices. $ sudo vi /etc/modprobe.d/blacklist.conf Add or update the lines: install usb-storage /bin/false blacklist usb-storage Reboot the system for the settings to take effect.

b
An OL 8 firewall must employ a deny-all, allow-by-exception policy for allowing connections to other systems.
AC-17 - Medium - CCI-002314 - V-248839 - SV-248839r943095_rule
RMF Control
AC-17
Severity
Medium
CCI
CCI-002314
Version
OL08-00-040090
Vuln IDs
  • V-248839
Rule IDs
  • SV-248839r943095_rule
Failure to restrict network connectivity only to authorized systems permits inbound connections from malicious systems. It also permits outbound connections that may facilitate exfiltration of DoD data. OL 8 incorporates the "firewalld" daemon, which allows for many different configurations. One of these configurations is zones. Zones can be used in a deny-all, allow-by-exception approach. The default "drop" zone will drop all incoming network packets unless it is explicitly allowed by the configuration file or is related to an outgoing network connection.
Checks: C-52273r943093_chk

Verify "firewalld" is configured to employ a deny-all, allow-by-exception policy for allowing connections to other systems with the following commands: $ sudo firewall-cmd --state running $ sudo firewall-cmd --get-active-zones [custom] interfaces: ens33 $ sudo firewall-cmd --info-zone=[custom] | grep target target: DROP If no zones are active on the OL 8 interfaces or if the target is set to an option other than "DROP", this is a finding. If the "firewalld" package is not installed, ask the System Administrator if an alternate firewall (such as iptables) is installed and in use, and how is it configured to employ a deny-all, allow-by-exception policy. If the alternate firewall is not configured to employ a deny-all, allow-by-exception policy, this is a finding. If no firewall is installed, this is a finding.

Fix: F-52227r943094_fix

Configure the "firewalld" daemon to employ a deny-all, allow-by-exception policy with the following commands: $ sudo firewall-cmd --permanent --new-zone=[custom] $ sudo cp /usr/lib/firewalld/zones/drop.xml /etc/firewalld/zones/[custom].xml This will provide a clean configuration file to work with that employs a deny-all approach. Note: Add the exceptions that are required for mission functionality and update the short title in the xml file to match the [custom] zone name. Reload the firewall rules to make the new [custom] zone available to load: $ sudo firewall-cmd --reload Set the default zone to the new [custom] zone: $ sudo firewall-cmd --set-default-zone=[custom] Note: This is a runtime and permanent change. Add any interfaces to the new [custom] zone: $ sudo firewall-cmd --permanent --zone=[custom] --change-interface=ens33 Reload the firewall rules for changes to take effect: $ sudo firewall-cmd --reload

b
A firewall must be installed on OL 8.
AC-17 - Medium - CCI-002314 - V-248840 - SV-248840r853847_rule
RMF Control
AC-17
Severity
Medium
CCI
CCI-002314
Version
OL08-00-040100
Vuln IDs
  • V-248840
Rule IDs
  • SV-248840r853847_rule
"Firewalld" provides an easy and effective way to block/limit remote access to the system via ports, services, and protocols. Remote access services, such as those providing remote access to network devices and information systems, which lack automated control capabilities, increase risk and make remote user access management difficult at best. Remote access is access to DoD nonpublic information systems by an authorized user (or an information system) communicating through an external, non-organization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. OL 8 functionality (e.g., RDP) must be capable of taking enforcement action if the audit reveals unauthorized activity. Automated control of remote access sessions allows organizations to ensure ongoing compliance with remote access policies by enforcing connection rules of remote access applications on a variety of information system components (e.g., servers, workstations, notebook computers, smartphones, and tablets).
Checks: C-52274r780084_chk

Verify that "firewalld" is installed with the following commands: $ sudo yum list installed firewalld firewalld.noarch 0.7.0-5.el8 If the "firewalld" package is not installed, ask the System Administrator if another firewall is installed. If no firewall is installed this is a finding.

Fix: F-52228r780085_fix

Install "firewalld" with the following commands: $ sudo yum install firewalld.noarch

b
A firewall must be active on OL 8.
AC-17 - Medium - CCI-002314 - V-248841 - SV-248841r853848_rule
RMF Control
AC-17
Severity
Medium
CCI
CCI-002314
Version
OL08-00-040101
Vuln IDs
  • V-248841
Rule IDs
  • SV-248841r853848_rule
"Firewalld" provides an easy and effective way to block/limit remote access to the system via ports, services, and protocols. Remote access services, such as those providing remote access to network devices and information systems, which lack automated control capabilities, increase risk and make remote user access management difficult at best. Remote access is access to DoD nonpublic information systems by an authorized user (or an information system) communicating through an external, non-organization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. OL 8 functionality (e.g., RDP) must be capable of taking enforcement action if the audit reveals unauthorized activity. Automated control of remote access sessions allows organizations to ensure ongoing compliance with remote access policies by enforcing connection rules of remote access applications on a variety of information system components (e.g., servers, workstations, notebook computers, smartphones, and tablets).
Checks: C-52275r780087_chk

Verify that "firewalld" is active with the following commands: $ sudo systemctl is-active firewalld active If the "firewalld" package is not "active", ask the System Administrator if another firewall is installed. If no firewall is installed and active this is a finding.

Fix: F-52229r780088_fix

Configure "firewalld" to protect the operating system with the following commands: $ sudo systemctl enable firewalld $ sudo systemctl start firewalld

b
OL 8 wireless network adapters must be disabled.
AC-18 - Medium - CCI-001443 - V-248842 - SV-248842r853849_rule
RMF Control
AC-18
Severity
Medium
CCI
CCI-001443
Version
OL08-00-040110
Vuln IDs
  • V-248842
Rule IDs
  • SV-248842r853849_rule
Without protection of communications with wireless peripherals, confidentiality and integrity may be compromised because unprotected communications can be intercepted and read, altered, or used to compromise the OL 8 operating system. This requirement applies to wireless peripheral technologies (e.g., wireless mice, keyboards, displays, etc.) used with OL 8 systems. Wireless peripherals (e.g., Wi-Fi/Bluetooth/IR keyboards, mice, and pointing devices and Near Field Communications [NFC]) present a unique challenge by creating an open, unsecured port on a computer. Wireless peripherals must meet DoD requirements for wireless data transmission and be approved for use by the Authorizing Official (AO). Although some wireless peripherals, such as mice and pointing devices, do not ordinarily carry information that need to be protected, modification of communications with these wireless peripherals may be used to compromise the OL 8 operating system. Communication paths outside the physical protection of a controlled boundary are exposed to the possibility of interception and modification. Protecting the confidentiality and integrity of communications with wireless peripherals can be accomplished by physical means (e.g., employing physical barriers to wireless radio frequencies) or by logical means (e.g., employing cryptographic techniques). If physical means of protection are employed, logical means (cryptography) do not have to be employed, and vice versa. If the wireless peripheral is only passing telemetry data, encryption of the data may not be required. Satisfies: SRG-OS-000299-GPOS-00117, SRG-OS-000300-GPOS-00118, SRG-OS-000481-GPOS-000481
Checks: C-52276r780090_chk

Verify there are no wireless interfaces configured on the system with the following command. Note: This requirement is not applicable for systems that do not have physical wireless network radios. $ sudo nmcli device status DEVICE TYPE STATE CONNECTION virbr0 bridge connected virbr0 wlp7s0 wifi connected wifiSSID enp6s0 ethernet disconnected -- p2p-dev-wlp7s0 wifi-p2p disconnected -- lo loopback unmanaged -- virbr0-nic tun unmanaged -- If a wireless interface is configured and has not been documented and approved by the Information System Security Officer (ISSO), this is a finding.

Fix: F-52230r780091_fix

Configure the system to disable all wireless network interfaces with the following command: $ sudo nmcli radio all off

b
OL 8 Bluetooth must be disabled.
AC-18 - Medium - CCI-001443 - V-248843 - SV-248843r943092_rule
RMF Control
AC-18
Severity
Medium
CCI
CCI-001443
Version
OL08-00-040111
Vuln IDs
  • V-248843
Rule IDs
  • SV-248843r943092_rule
Without protection of communications with wireless peripherals, confidentiality and integrity may be compromised because unprotected communications can be intercepted and read, altered, or used to compromise the OL 8 operating system. This requirement applies to wireless peripheral technologies (e.g., wireless mice, keyboards, displays, etc.) used with OL 8 systems. Wireless peripherals (e.g., Wi-Fi/Bluetooth/IR keyboards, mice, and pointing devices and Near Field Communications [NFC]) present a unique challenge by creating an open, unsecured port on a computer. Wireless peripherals must meet DoD requirements for wireless data transmission and be approved for use by the Authorizing Official (AO). Although some wireless peripherals, such as mice and pointing devices, do not ordinarily carry information that need to be protected, modification of communications with these wireless peripherals may be used to compromise the OL 8 operating system. Communication paths outside the physical protection of a controlled boundary are exposed to the possibility of interception and modification. Protecting the confidentiality and integrity of communications with wireless peripherals can be accomplished by physical means (e.g., employing physical barriers to wireless radio frequencies) or by logical means (e.g., employing cryptographic techniques). If physical means of protection are employed, logical means (cryptography) do not have to be employed, and vice versa. If the wireless peripheral is only passing telemetry data, encryption of the data may not be required.
Checks: C-52277r943090_chk

If the device or operating system does not have a Bluetooth adapter installed, this requirement is not applicable. This requirement is not applicable to mobile devices (smartphones and tablets), where the use of Bluetooth is a local AO decision. Determine if Bluetooth is disabled with the following command: $ sudo grep -r bluetooth /etc/modprobe.d /etc/modprobe.d/bluetooth.conf:install bluetooth /bin/false If the command does not return any output or the line is commented out and the collaborative computing device has not been authorized for use, this is a finding. Verify the operating system disables the ability to use Bluetooth with the following command: $ sudo grep -r bluetooth /etc/modprobe.d | grep -i "blacklist" | grep -v "^#" blacklist bluetooth If the command does not return any output or the output is not "blacklist bluetooth", and use of Bluetooth is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding.

Fix: F-52231r943091_fix

Configure the operating system to disable the Bluetooth adapter when not in use. Build or modify the "/etc/modprobe.d/bluetooth.conf" file with the following line: install bluetooth /bin/false Disable the ability to use the Bluetooth kernel module. $ sudo vi /etc/modprobe.d/blacklist.conf Add or update the line: blacklist bluetooth Reboot the system for the settings to take effect.

b
OL 8 must mount "/dev/shm" with the "nodev" option.
CM-7 - Medium - CCI-001764 - V-248844 - SV-248844r853853_rule
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040120
Vuln IDs
  • V-248844
Rule IDs
  • SV-248844r853853_rule
The organization must identify authorized software programs and permit execution of authorized software. The process used to identify software programs that are authorized to execute on organizational information systems is commonly referred to as whitelisting. The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-52278r780096_chk

Verify "/dev/shm" is mounted with the "nodev" option: $ sudo mount | grep /dev/shm tmpfs on /dev/shm type tmpfs (rw,nodev,nosuid,noexec,seclabel) Verify that the "nodev" option is configured for "/dev/shm": $ sudo cat /etc/fstab | grep /dev/shm tmpfs /dev/shm tmpfs defaults,nodev,nosuid,noexec 0 0 If results are returned and the "nodev" option is missing, or if "/dev/shm" is mounted without the "nodev" option, this is a finding.

Fix: F-52232r780097_fix

Configure OL 8 so that "/dev/shm" is mounted with the "nodev" option by adding/modifying "/etc/fstab" with the following line: tmpfs /dev/shm tmpfs defaults,nodev,nosuid,noexec 0 0

b
OL 8 must mount "/dev/shm" with the "nosuid" option.
CM-7 - Medium - CCI-001764 - V-248845 - SV-248845r853854_rule
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040121
Vuln IDs
  • V-248845
Rule IDs
  • SV-248845r853854_rule
The organization must identify authorized software programs and permit execution of authorized software. The process used to identify software programs that are authorized to execute on organizational information systems is commonly referred to as whitelisting. The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-52279r780099_chk

Verify "/dev/shm" is mounted with the "nosuid" option: $ sudo mount | grep /dev/shm tmpfs on /dev/shm type tmpfs (rw,nodev,nosuid,noexec,seclabel) Verify that the "nosuid" option is configured for "/dev/shm": $ sudo cat /etc/fstab | grep /dev/shm tmpfs /dev/shm tmpfs defaults,nodev,nosuid,noexec 0 0 If results are returned and the "nosuid" option is missing, or if "/dev/shm" is mounted without the "nosuid" option, this is a finding.

Fix: F-52233r780100_fix

Configure OL 8 so that "/dev/shm" is mounted with the "nosuid" option by adding/modifying "/etc/fstab" with the following line: tmpfs /dev/shm tmpfs defaults,nodev,nosuid,noexec 0 0

b
OL 8 must mount "/dev/shm" with the "noexec" option.
CM-7 - Medium - CCI-001764 - V-248846 - SV-248846r853855_rule
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040122
Vuln IDs
  • V-248846
Rule IDs
  • SV-248846r853855_rule
The organization must identify authorized software programs and permit execution of authorized software. The process used to identify software programs that are authorized to execute on organizational information systems is commonly referred to as whitelisting. The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-52280r780102_chk

Verify "/dev/shm" is mounted with the "noexec" option: $ sudo mount | grep /dev/shm tmpfs on /dev/shm type tmpfs (rw,nodev,nosuid,noexec,seclabel) Verify that the "noexec" option is configured for "/dev/shm": $ sudo cat /etc/fstab | grep /dev/shm tmpfs /dev/shm tmpfs defaults,nodev,nosuid,noexec 0 0 If results are returned and the "noexec" option is missing, or if "/dev/shm" is mounted without the "noexec" option, this is a finding.

Fix: F-52234r780103_fix

Configure OL 8 so that "/dev/shm" is mounted with the "noexec" option by adding/modifying "/etc/fstab" with the following line: tmpfs /dev/shm tmpfs defaults,nodev,nosuid,noexec 0 0

b
OL 8 must mount "/tmp" with the "nodev" option.
CM-7 - Medium - CCI-001764 - V-248847 - SV-248847r853856_rule
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040123
Vuln IDs
  • V-248847
Rule IDs
  • SV-248847r853856_rule
The organization must identify authorized software programs and permit execution of authorized software. The process used to identify software programs that are authorized to execute on organizational information systems is commonly referred to as whitelisting. The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-52281r780105_chk

Verify "/tmp" is mounted with the "nodev" option: $ sudo mount | grep /tmp /dev/mapper/ol-tmp on /tmp type xfs (rw,nodev,nosuid,noexec,seclabel) Verify that the "nodev" option is configured for /tmp: $ sudo cat /etc/fstab | grep /tmp /dev/mapper/ol-tmp /tmp xfs defaults,nodev,nosuid,noexec 0 0 If results are returned and the "nodev" option is missing, or if /tmp is mounted without the "nodev" option, this is a finding.

Fix: F-52235r780106_fix

Configure the system so that /tmp is mounted with the "nodev" option by adding /modifying the /etc/fstab with the following line: /dev/mapper/ol-tmp /tmp xfs defaults,nodev,nosuid,noexec 0 0

b
OL 8 must mount "/tmp" with the "nosuid" option.
CM-7 - Medium - CCI-001764 - V-248848 - SV-248848r853857_rule
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040124
Vuln IDs
  • V-248848
Rule IDs
  • SV-248848r853857_rule
The organization must identify authorized software programs and permit execution of authorized software. The process used to identify software programs that are authorized to execute on organizational information systems is commonly referred to as whitelisting. The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-52282r780108_chk

Verify "/tmp" is mounted with the "nosuid" option: $ sudo mount | grep /tmp /dev/mapper/ol-tmp on /tmp type xfs (rw,nodev,nosuid,noexec,seclabel) Verify that the "nosuid" option is configured for /tmp: $ sudo cat /etc/fstab | grep /tmp /dev/mapper/ol-tmp /tmp xfs defaults,nodev,nosuid,noexec 0 0 If results are returned and the "nosuid" option is missing, or if /tmp is mounted without the "nosuid" option, this is a finding.

Fix: F-52236r780109_fix

Configure the system so that /tmp is mounted with the "nosuid" option by adding /modifying the /etc/fstab with the following line: /dev/mapper/ol-tmp /tmp xfs defaults,nodev,nosuid,noexec 0 0

b
OL 8 must mount "/tmp" with the "noexec" option.
CM-7 - Medium - CCI-001764 - V-248849 - SV-248849r853858_rule
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040125
Vuln IDs
  • V-248849
Rule IDs
  • SV-248849r853858_rule
The organization must identify authorized software programs and permit execution of authorized software. The process used to identify software programs that are authorized to execute on organizational information systems is commonly referred to as whitelisting. The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-52283r780111_chk

Verify "/tmp" is mounted with the "noexec" option: $ sudo mount | grep /tmp /dev/mapper/ol-tmp on /tmp type xfs (rw,nodev,nosuid,noexec,seclabel) Verify that the "noexec" option is configured for /tmp: $ sudo cat /etc/fstab | grep /tmp /dev/mapper/ol-tmp /tmp xfs defaults,nodev,nosuid,noexec 0 0 If results are returned and the "noexec" option is missing, or if /tmp is mounted without the "noexec" option, this is a finding.

Fix: F-52237r780112_fix

Configure the system so that /tmp is mounted with the "noexec" option by adding /modifying the /etc/fstab with the following line: /dev/mapper/ol-tmp /tmp xfs defaults,nodev,nosuid,noexec 0 0

b
OL 8 must mount "/var/log" with the "nodev" option.
CM-7 - Medium - CCI-001764 - V-248850 - SV-248850r853859_rule
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040126
Vuln IDs
  • V-248850
Rule IDs
  • SV-248850r853859_rule
The organization must identify authorized software programs and permit execution of authorized software. The process used to identify software programs that are authorized to execute on organizational information systems is commonly referred to as whitelisting. The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-52284r780114_chk

Verify "/var/log" is mounted with the "nodev" option: $ sudo mount | grep /var/log /dev/mapper/ol-var_log on /var/log type xfs (rw,nodev,nosuid,noexec,seclabel) Verify that the "nodev" option is configured for /var/log: $ sudo cat /etc/fstab | grep /var/log /dev/mapper/ol-var_log /var/log xfs defaults,nodev,nosuid,noexec 0 0 If results are returned and the "nodev" option is missing, or if /var/log is mounted without the "nodev" option, this is a finding.

Fix: F-52238r780115_fix

Configure the system so that /var/log is mounted with the "nodev" option by adding /modifying the /etc/fstab with the following line: /dev/mapper/ol-var_log /var/log xfs defaults,nodev,nosuid,noexec 0 0

b
OL 8 must mount "/var/log" with the "nosuid" option.
CM-7 - Medium - CCI-001764 - V-248851 - SV-248851r853860_rule
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040127
Vuln IDs
  • V-248851
Rule IDs
  • SV-248851r853860_rule
The organization must identify authorized software programs and permit execution of authorized software. The process used to identify software programs that are authorized to execute on organizational information systems is commonly referred to as whitelisting. The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-52285r780117_chk

Verify "/var/log" is mounted with the "nosuid" option: $ sudo mount | grep /var/log /dev/mapper/ol-var_log on /var/log type xfs (rw,nodev,nosuid,noexec,seclabel) Verify that the "nosuid" option is configured for /var/log: $ sudo cat /etc/fstab | grep /var/log /dev/mapper/ol-var_log /var/log xfs defaults,nodev,nosuid,noexec 0 0 If results are returned and the "nosuid" option is missing, or if /var/log is mounted without the "nosuid" option, this is a finding.

Fix: F-52239r780118_fix

Configure the system so that /var/log is mounted with the "nosuid" option by adding /modifying the /etc/fstab with the following line: /dev/mapper/ol-var_log /var/log xfs defaults,nodev,nosuid,noexec 0 0

b
OL 8 must mount "/var/log" with the "noexec" option.
CM-7 - Medium - CCI-001764 - V-248852 - SV-248852r853861_rule
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040128
Vuln IDs
  • V-248852
Rule IDs
  • SV-248852r853861_rule
The organization must identify authorized software programs and permit execution of authorized software. The process used to identify software programs that are authorized to execute on organizational information systems is commonly referred to as whitelisting. The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-52286r780120_chk

Verify "/var/log" is mounted with the "noexec" option: $ sudo mount | grep /var/log /dev/mapper/ol-var_log on /var/log type xfs (rw,nodev,nosuid,noexec,seclabel) Verify that the "noexec" option is configured for /var/log: $ sudo cat /etc/fstab | grep /var/log /dev/mapper/ol-var_log /var/log xfs defaults,nodev,nosuid,noexec 0 0 If results are returned and the "noexec" option is missing, or if /var/log is mounted without the "noexec" option, this is a finding.

Fix: F-52240r780121_fix

Configure the system so that /var/log is mounted with the "noexec" option by adding /modifying the /etc/fstab with the following line: /dev/mapper/ol-var_log /var/log xfs defaults,nodev,nosuid,noexec 0 0

b
OL 8 must mount "/var/log/audit" with the "nodev" option.
CM-7 - Medium - CCI-001764 - V-248853 - SV-248853r853862_rule
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040129
Vuln IDs
  • V-248853
Rule IDs
  • SV-248853r853862_rule
The organization must identify authorized software programs and permit execution of authorized software. The process used to identify software programs that are authorized to execute on organizational information systems is commonly referred to as whitelisting. The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-52287r780123_chk

Verify "/var/log/audit" is mounted with the "nodev" option: $ sudo mount | grep /var/log/audit /dev/mapper/ol-var_log_audit on /var/log/audit type xfs (rw,nodev,nosuid,noexec,seclabel) Verify that the "nodev" option is configured for /var/log/audit: $ sudo cat /etc/fstab | grep /var/log/audit /dev/mapper/ol-var_log_audit /var/log/audit xfs defaults,nodev,nosuid,noexec 0 0 If results are returned and the "nodev" option is missing, or if /var/log/audit is mounted without the "nodev" option, this is a finding.

Fix: F-52241r780124_fix

Configure the system so that /var/log/audit is mounted with the "nodev" option by adding /modifying the /etc/fstab with the following line: /dev/mapper/ol-var_log_audit /var/log/audit xfs defaults,nodev,nosuid,noexec 0 0

b
OL 8 must mount "/var/log/audit" with the "nosuid" option.
CM-7 - Medium - CCI-001764 - V-248854 - SV-248854r853863_rule
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040130
Vuln IDs
  • V-248854
Rule IDs
  • SV-248854r853863_rule
The organization must identify authorized software programs and permit execution of authorized software. The process used to identify software programs that are authorized to execute on organizational information systems is commonly referred to as whitelisting. The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-52288r780126_chk

Verify "/var/log/audit" is mounted with the "nosuid" option: $ sudo mount | grep /var/log/audit /dev/mapper/ol-var_log_audit on /var/log/audit type xfs (rw,nodev,nosuid,noexec,seclabel) Verify that the "nosuid" option is configured for /var/log/audit: $ sudo cat /etc/fstab | grep /var/log/audit /dev/mapper/ol-var_log_audit /var/log/audit xfs defaults,nodev,nosuid,noexec 0 0 If results are returned and the "nosuid" option is missing, or if /var/log/audit is mounted without the "nosuid" option, this is a finding.

Fix: F-52242r780127_fix

Configure the system so that /var/log/audit is mounted with the "nosuid" option by adding /modifying the /etc/fstab with the following line: /dev/mapper/ol-var_log_audit /var/log/audit xfs defaults,nodev,nosuid,noexec 0 0

b
OL 8 must mount "/var/log/audit" with the "noexec" option.
CM-7 - Medium - CCI-001764 - V-248855 - SV-248855r853864_rule
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040131
Vuln IDs
  • V-248855
Rule IDs
  • SV-248855r853864_rule
The organization must identify authorized software programs and permit execution of authorized software. The process used to identify software programs that are authorized to execute on organizational information systems is commonly referred to as whitelisting. The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-52289r780129_chk

Verify "/var/log/audit" is mounted with the "noexec" option: $ sudo mount | grep /var/log/audit /dev/mapper/ol-var_log_audit on /var/log/audit type xfs (rw,nodev,nosuid,noexec,seclabel) Verify that the "noexec" option is configured for /var/log/audit: $ sudo cat /etc/fstab | grep /var/log/audit /dev/mapper/ol-var_log_audit /var/log/audit xfs defaults,nodev,nosuid,noexec 0 0 If results are returned and the "noexec" option is missing, or if /var/log/audit is mounted without the "noexec" option, this is a finding.

Fix: F-52243r780130_fix

Configure the system so that /var/log/audit is mounted with the "noexec" option by adding /modifying the /etc/fstab with the following line: /dev/mapper/ol-var_log_audit /var/log/audit xfs defaults,nodev,nosuid,noexec 0 0

b
OL 8 must mount "/var/tmp" with the "nodev" option.
CM-7 - Medium - CCI-001764 - V-248856 - SV-248856r853865_rule
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040132
Vuln IDs
  • V-248856
Rule IDs
  • SV-248856r853865_rule
The organization must identify authorized software programs and permit execution of authorized software. The process used to identify software programs that are authorized to execute on organizational information systems is commonly referred to as whitelisting. The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-52290r780132_chk

Verify "/var/tmp" is mounted with the "nodev" option: $ sudo mount | grep /var/tmp /dev/mapper/ol-var_tmp on /var/tmp type xfs (rw,nodev,nosuid,noexec,seclabel) Verify that the "nodev" option is configured for /var/tmp: $ sudo cat /etc/fstab | grep /var/tmp /dev/mapper/ol-var_tmp /var/tmp xfs defaults,nodev,nosuid,noexec 0 0 If results are returned and the "nodev" option is missing, or if /var/tmp is mounted without the "nodev" option, this is a finding.

Fix: F-52244r780133_fix

Configure the system so that /var/tmp is mounted with the "nodev" option by adding /modifying the /etc/fstab with the following line: /dev/mapper/ol-var_tmp /var/tmp xfs defaults,nodev,nosuid,noexec 0 0

b
OL 8 must mount "/var/tmp" with the "nosuid" option.
CM-7 - Medium - CCI-001764 - V-248857 - SV-248857r853866_rule
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040133
Vuln IDs
  • V-248857
Rule IDs
  • SV-248857r853866_rule
The organization must identify authorized software programs and permit execution of authorized software. The process used to identify software programs that are authorized to execute on organizational information systems is commonly referred to as whitelisting. The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-52291r780135_chk

Verify "/var/tmp" is mounted with the "nosuid" option: $ sudo mount | grep /var/tmp /dev/mapper/ol-var_tmp on /var/tmp type xfs (rw,nodev,nosuid,noexec,seclabel) Verify that the "nosuid" option is configured for /var/tmp: $ sudo cat /etc/fstab | grep /var/tmp /dev/mapper/ol-var_tmp /var/tmp xfs defaults,nodev,nosuid,noexec 0 0 If results are returned and the "nosuid" option is missing, or if /var/tmp is mounted without the "nosuid" option, this is a finding.

Fix: F-52245r780136_fix

Configure the system so that /var/tmp is mounted with the "nosuid" option by adding /modifying the /etc/fstab with the following line: /dev/mapper/ol-var_tmp /var/tmp xfs defaults,nodev,nosuid,noexec 0 0

b
OL 8 must mount "/var/tmp" with the "noexec" option.
CM-7 - Medium - CCI-001764 - V-248858 - SV-248858r853867_rule
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040134
Vuln IDs
  • V-248858
Rule IDs
  • SV-248858r853867_rule
The organization must identify authorized software programs and permit execution of authorized software. The process used to identify software programs that are authorized to execute on organizational information systems is commonly referred to as whitelisting. The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-52292r780138_chk

Verify "/var/tmp" is mounted with the "noexec" option: $ sudo mount | grep /var/tmp /dev/mapper/ol-var_tmp on /var/tmp type xfs (rw,nodev,nosuid,noexec,seclabel) Verify that the "noexec" option is configured for /var/tmp: $ sudo cat /etc/fstab | grep /var/tmp /dev/mapper/ol-var_tmp /var/tmp xfs defaults,nodev,nosuid,noexec 0 0 If results are returned and the "noexec" option is missing, or if /var/tmp is mounted without the "noexec" option, this is a finding.

Fix: F-52246r780139_fix

Configure the system so that /var/tmp is mounted with the "noexec" option by adding /modifying the /etc/fstab with the following line: /dev/mapper/ol-var_tmp /var/tmp xfs defaults,nodev,nosuid,noexec 0 0

b
The OL 8 "fapolicy" module must be installed.
CM-7 - Medium - CCI-001764 - V-248859 - SV-248859r853868_rule
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040135
Vuln IDs
  • V-248859
Rule IDs
  • SV-248859r853868_rule
The organization must identify authorized software programs and permit execution of authorized software. The process used to identify software programs that are authorized to execute on organizational information systems is commonly referred to as whitelisting. Using a whitelist provides a configuration management method for allowing the execution of only authorized software. Using only authorized software decreases risk by limiting the number of potential vulnerabilities. Verification of whitelisted software occurs prior to execution or at system startup. Users' home directories/folders may contain information of a sensitive nature. Non-privileged users should coordinate any sharing of information with a System Administrator through shared resources. OL 8 ships with many optional packages. One such package is a file access policy daemon called "fapolicyd". This is a userspace daemon that determines access rights to files based on attributes of the process and file. It can be used to either blacklist or whitelist processes or file access. Proceed with caution with enforcing the use of this daemon. Improper configuration may render the system non-functional. The "fapolicyd" API is not namespace aware and can cause issues when launching or running containers. Satisfies: SRG-OS-000368-GPOS-00154, SRG-OS-000370-GPOS-00155
Checks: C-52293r780141_chk

Verify the OL 8 "fapolicyd" is installed. Check that "fapolicyd" is installed with the following command: $ sudo yum list installed fapolicyd Installed Packages fapolicyd.x86_64 If "fapolicyd" is not installed, this is a finding.

Fix: F-52247r780142_fix

Install "fapolicyd" with the following command: $ sudo yum install fapolicyd.x86_64

b
The OL 8 "fapolicy" module must be enabled.
CM-7 - Medium - CCI-001764 - V-248860 - SV-248860r853869_rule
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040136
Vuln IDs
  • V-248860
Rule IDs
  • SV-248860r853869_rule
The organization must identify authorized software programs and permit execution of authorized software. The process used to identify software programs that are authorized to execute on organizational information systems is commonly referred to as whitelisting. Using a whitelist provides a configuration management method for allowing the execution of only authorized software. Using only authorized software decreases risk by limiting the number of potential vulnerabilities. Verification of whitelisted software occurs prior to execution or at system startup. Users' home directories/folders may contain information of a sensitive nature. Non-privileged users should coordinate any sharing of information with a System Administrator through shared resources. OL 8 ships with many optional packages. One such package is a file access policy daemon called "fapolicyd". This is a userspace daemon that determines access rights to files based on attributes of the process and file. It can be used to either blacklist or whitelist processes or file access. Proceed with caution with enforcing the use of this daemon. Improper configuration may render the system non-functional. The "fapolicyd" API is not namespace aware and can cause issues when launching or running containers. Satisfies: SRG-OS-000368-GPOS-00154, SRG-OS-000370-GPOS-00155
Checks: C-52294r780144_chk

Verify the OL 8 "fapolicyd" is enabled and running with the following command: $ sudo systemctl status fapolicyd.service fapolicyd.service - File Access Policy Daemon Loaded: loaded (/usr/lib/systemd/system/fapolicyd.service; enabled; vendor preset: disabled) Active: active (running) If fapolicyd is not enabled and running, this is a finding.

Fix: F-52248r780145_fix

Enable "fapolicyd" using the following command: $ sudo systemctl enable --now fapolicyd

b
The OL 8 fapolicy module must be configured to employ a deny-all, permit-by-exception policy to allow the execution of authorized software programs.
CM-7 - Medium - CCI-001764 - V-248861 - SV-248861r860922_rule
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040137
Vuln IDs
  • V-248861
Rule IDs
  • SV-248861r860922_rule
The organization must identify authorized software programs and permit execution of authorized software. The process used to identify software programs that are authorized to execute on organizational information systems is commonly referred to as whitelisting. Using a whitelist provides a configuration management method for allowing the execution of only authorized software. Using only authorized software decreases risk by limiting the number of potential vulnerabilities. Verification of whitelisted software occurs prior to execution or at system startup. Users' home directories/folders may contain information of a sensitive nature. Non-privileged users should coordinate any sharing of information with a System Administrator through shared resources. OL 8 ships with many optional packages. One such package is a file access policy daemon called "fapolicyd". This is a userspace daemon that determines access rights to files based on attributes of the process and file. It can be used to either blacklist or whitelist processes or file access. Proceed with caution with enforcing the use of this daemon. Improper configuration may render the system non-functional. The "fapolicyd" API is not namespace aware and can cause issues when launching or running containers. Satisfies: SRG-OS-000368-GPOS-00154, SRG-OS-000370-GPOS-00155
Checks: C-52295r858593_chk

Verify the OL 8 "fapolicyd" employs a deny-all, permit-by-exception policy. Check that "fapolicyd" is in enforcement mode with the following command: $ sudo grep permissive /etc/fapolicyd/fapolicyd.conf permissive = 0 Check that fapolicyd employs a deny-all policy on system mounts with the following commands: For OL 8.4 systems and older: $ sudo tail /etc/fapolicyd/fapolicyd.rules For OL 8.5 systems and newer: $ sudo tail /etc/fapolicyd/compiled.rules allow exe=/usr/bin/python3.7 : ftype=text/x-python deny_audit perm=any pattern=ld_so : all deny perm=any all : all If fapolicyd is not running in enforcement mode with a deny-all, permit-by-exception policy, this is a finding.

Fix: F-52249r858594_fix

Configure OL 8 to employ a deny-all, permit-by-exception application whitelisting policy with "fapolicyd". With the "fapolicyd" installed and enabled, configure the daemon to function in permissive mode until the whitelist is built correctly to avoid system lockout. Do this by editing the "/etc/fapolicyd/fapolicyd.conf" file with the following line: permissive = 1 For OL 8.4 systems and older: Build the whitelist in the "/etc/fapolicyd/fapolicyd.rules" file ensuring the last rule is "deny perm=any all : all". For OL 8.5 systems and newer: Build the whitelist in a file within the "/etc/fapolicyd/rules.d" directory ensuring the last rule is "deny perm=any all : all". Once it is determined the whitelist is built correctly, set the fapolicyd to enforcing mode by editing the "permissive" line in the /etc/fapolicyd/fapolicyd.conf file. permissive = 0

b
OL 8 must have the USBGuard installed.
IA-3 - Medium - CCI-001958 - V-248862 - SV-248862r853871_rule
RMF Control
IA-3
Severity
Medium
CCI
CCI-001958
Version
OL08-00-040139
Vuln IDs
  • V-248862
Rule IDs
  • SV-248862r853871_rule
Without authenticating devices, unidentified or unknown devices may be introduced, thereby facilitating malicious activity. Peripherals include but are not limited to such devices as flash drives, external storage, and printers. A new feature that OL 8 provides is the USBGuard software framework. The USBguard-daemon is the main component of the USBGuard software framework. It runs as a service in the background and enforces the USB device authorization policy for all USB devices. The policy is defined by a set of rules using a rule language described in the "usbguard-rules.conf" file. The policy and the authorization state of USB devices can be modified during runtime using the "usbguard" tool. The System Administrator (SA) must work with the site Information System Security Officer (ISSO) to determine a list of authorized peripherals and establish rules within the USBGuard software framework to allow only authorized devices.
Checks: C-52296r780150_chk

Verify USBGuard is installed on the operating system with the following command: $ sudo yum list installed usbguard Installed Packages usbguard.x86_64 0.7.8-7.el8 @ol8_appstream If the USBGuard package is not installed, ask the SA to indicate how unauthorized peripherals are being blocked. If there is no evidence that unauthorized peripherals are being blocked before establishing a connection, this is a finding.

Fix: F-52250r780151_fix

Install the USBGuard package with the following command: $ sudo yum install usbguard.x86_64

b
OL 8 must block unauthorized peripherals before establishing a connection.
IA-3 - Medium - CCI-001958 - V-248863 - SV-248863r853872_rule
RMF Control
IA-3
Severity
Medium
CCI
CCI-001958
Version
OL08-00-040140
Vuln IDs
  • V-248863
Rule IDs
  • SV-248863r853872_rule
Without authenticating devices, unidentified or unknown devices may be introduced, thereby facilitating malicious activity. Peripherals include but are not limited to such devices as flash drives, external storage, and printers. A new feature that OL 8 provides is the USBGuard software framework. The USBguard-daemon is the main component of the USBGuard software framework. It runs as a service in the background and enforces the USB device authorization policy for all USB devices. The policy is defined by a set of rules using a rule language described in the "usbguard-rules.conf" file. The policy and the authorization state of USB devices can be modified during runtime using the "usbguard" tool. The System Administrator (SA) must work with the site Information System Security Officer (ISSO) to determine a list of authorized peripherals and establish rules within the USBGuard software framework to allow only authorized devices.
Checks: C-52297r780153_chk

Verify the USBGuard has a policy configured with the following command: $ sudo usbguard list-rules If the command does not return results or an error is returned, ask the SA to indicate how unauthorized peripherals are being blocked. If there is no evidence that unauthorized peripherals are being blocked before establishing a connection, this is a finding.

Fix: F-52251r780154_fix

Configure the operating system to enable the blocking of unauthorized peripherals with the following command: This command must be run from a root shell and will create an allow list for any usb devices currently connect to the system. # usbguard generate-policy > /etc/usbguard/rules.conf Note: Enabling and starting usbguard without properly configuring it for an individual system will immediately prevent any access over a usb device such as a keyboard or mouse.

b
OL 8 must enable the USBGuard.
IA-3 - Medium - CCI-001958 - V-248864 - SV-248864r853873_rule
RMF Control
IA-3
Severity
Medium
CCI
CCI-001958
Version
OL08-00-040141
Vuln IDs
  • V-248864
Rule IDs
  • SV-248864r853873_rule
Without authenticating devices, unidentified or unknown devices may be introduced, thereby facilitating malicious activity. Peripherals include but are not limited to such devices as flash drives, external storage, and printers. A new feature that OL 8 provides is the USBGuard software framework. The USBguard-daemon is the main component of the USBGuard software framework. It runs as a service in the background and enforces the USB device authorization policy for all USB devices. The policy is defined by a set of rules using a rule language described in the "usbguard-rules.conf" file. The policy and the authorization state of USB devices can be modified during runtime using the "usbguard" tool. The System Administrator (SA) must work with the site Information System Security Officer (ISSO) to determine a list of authorized peripherals and establish rules within the USBGuard software framework to allow only authorized devices.
Checks: C-52298r780156_chk

Verify the operating system has enabled the use of the USBGuard with the following command: $ sudo systemctl status usbguard.service usbguard.service - USBGuard daemon Loaded: loaded (/usr/lib/systemd/system/usbguard.service; enabled; vendor preset: disabled) Active: active (running) If the usbguard.service is not enabled and active, ask the SA to indicate how unauthorized peripherals are being blocked. If there is no evidence that unauthorized peripherals are being blocked before establishing a connection, this is a finding.

Fix: F-52252r780157_fix

Configure the operating system to enable the blocking of unauthorized peripherals with the following commands: $ sudo systemctl enable usbguard.service $ sudo systemctl start usbguard.service Note: Enabling and starting usbguard without properly configuring it for an individual system will immediately prevent any access over a usb device such as a keyboard or mouse.

b
A firewall must be able to protect against or limit the effects of denial-of-service (DoS) attacks by ensuring OL 8 can implement rate-limiting measures on impacted network interfaces.
SC-5 - Medium - CCI-001095 - V-248865 - SV-248865r902788_rule
RMF Control
SC-5
Severity
Medium
CCI
CCI-001095
Version
OL08-00-040150
Vuln IDs
  • V-248865
Rule IDs
  • SV-248865r902788_rule
DoS is a condition when a resource is not available for legitimate users. When this occurs, the organization either cannot accomplish its mission or must operate at degraded capacity. This requirement addresses the configuration of OL 8 to mitigate the impact of DoS attacks that have occurred or are ongoing on system availability. For each system, known and potential DoS attacks must be identified and solutions for each type implemented. A variety of technologies exists to limit or, in some cases, eliminate the effects of DoS attacks (e.g., limiting processes or establishing memory partitions). Employing increased capacity and bandwidth, combined with service redundancy, may reduce the susceptibility to some DoS attacks. Since version 0.6.0, "firewalld" has incorporated "nftables" as its backend support. Using the limit statement in "nftables" can help to mitigate DoS attacks. Satisfies: SRG-OS-000142-GPOS-00071, SRG-OS-000298-GPOS-00116, SRG-OS-000420-GPOS-00186
Checks: C-52299r780159_chk

Verify "nftables" is configured to allow rate limits on any connection to the system with the following command. Verify "firewalld" has "nftables" set as the default backend: $ sudo grep -i firewallbackend /etc/firewalld/firewalld.conf # FirewallBackend FirewallBackend=nftables If the "nftables" is not set as the "firewallbackend" default, this is a finding.

Fix: F-52253r902787_fix

Configure "nftables" to be the default "firewallbackend" for "firewalld" by adding or editing the following line in "/etc/firewalld/firewalld.conf": FirewallBackend=nftables Establish rate-limiting rules based on organization-defined types of DoS attacks on impacted network interfaces.

b
All OL 8 networked systems must have SSH installed.
SC-8 - Medium - CCI-002418 - V-248866 - SV-248866r916422_rule
RMF Control
SC-8
Severity
Medium
CCI
CCI-002418
Version
OL08-00-040159
Vuln IDs
  • V-248866
Rule IDs
  • SV-248866r916422_rule
Without protection of the transmitted information, confidentiality and integrity may be compromised because unprotected communications can be intercepted and read or altered. This requirement applies to both internal and external networks and all types of information system components from which information can be transmitted (e.g., servers, mobile devices, notebook computers, printers, copiers, scanners, and facsimile machines). Communication paths outside the physical protection of a controlled boundary are exposed to the possibility of interception and modification. Protecting the confidentiality and integrity of organizational information can be accomplished by physical means (e.g., employing physical distribution systems) or by logical means (e.g., employing cryptographic techniques). If physical means of protection are employed, logical means (cryptography) do not have to be employed, and vice versa. Satisfies: SRG-OS-000423-GPOS-00187, SRG-OS-000424-GPOS-00188, SRG-OS-000425-GPOS-00189, SRG-OS-000426-GPOS-00190
Checks: C-52300r780162_chk

Verify SSH is installed with the following command: $ sudo yum list installed openssh-server openssh-server.x86_64 8.0p1-5.el8 @anaconda If the "SSH server" package is not installed, this is a finding.

Fix: F-52254r780163_fix

Install SSH packages onto the host with the following command: $ sudo yum install openssh-server.x86_64

b
All OL 8 networked systems must have and implement SSH to protect the confidentiality and integrity of transmitted and received information, as well as information during preparation for transmission.
SC-8 - Medium - CCI-002418 - V-248867 - SV-248867r916422_rule
RMF Control
SC-8
Severity
Medium
CCI
CCI-002418
Version
OL08-00-040160
Vuln IDs
  • V-248867
Rule IDs
  • SV-248867r916422_rule
Without protection of the transmitted information, confidentiality and integrity may be compromised because unprotected communications can be intercepted and read or altered. This requirement applies to both internal and external networks and all types of information system components from which information can be transmitted (e.g., servers, mobile devices, notebook computers, printers, copiers, scanners, and facsimile machines). Communication paths outside the physical protection of a controlled boundary are exposed to the possibility of interception and modification. Protecting the confidentiality and integrity of organizational information can be accomplished by physical means (e.g., employing physical distribution systems) or by logical means (e.g., employing cryptographic techniques). If physical means of protection are employed, logical means (cryptography) do not have to be employed, and vice versa. Satisfies: SRG-OS-000423-GPOS-00187, SRG-OS-000424-GPOS-00188, SRG-OS-000425-GPOS-00189, SRG-OS-000426-GPOS-00190
Checks: C-52301r780165_chk

Verify SSH is loaded and active with the following command: $ sudo systemctl status sshd sshd.service - OpenSSH server daemon Loaded: loaded (/usr/lib/systemd/system/sshd.service; enabled) Active: active (running) since Tue 2015-11-17 15:17:22 EST; 4 weeks 0 days ago Main PID: 1348 (sshd) CGroup: /system.slice/sshd.service 1053 /usr/sbin/sshd -D If "sshd" does not show a status of "active" and "running", this is a finding.

Fix: F-52255r780166_fix

Configure the SSH service to automatically start after reboot with the following command: $ sudo systemctl enable sshd.service

b
OL 8 must force a frequent session key renegotiation for SSH connections to the server.
AC-17 - Medium - CCI-000068 - V-248868 - SV-248868r877398_rule
RMF Control
AC-17
Severity
Medium
CCI
CCI-000068
Version
OL08-00-040161
Vuln IDs
  • V-248868
Rule IDs
  • SV-248868r877398_rule
Unapproved mechanisms that are used for authentication to the cryptographic module are not verified and therefore cannot be relied on to provide confidentiality or integrity, and DoD data may be compromised. Operating systems using encryption are required to use FIPS-compliant mechanisms for authenticating to cryptographic modules. Session key regeneration limits the chances of a session key becoming compromised.
Checks: C-52302r858585_chk

Verify the SSH server is configured to force frequent session key renegotiation with the following command: $ sudo grep -ir RekeyLimit /etc/ssh/sshd_config* RekeyLimit 1G 1h If "RekeyLimit" does not have a maximum data amount and maximum time defined or is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52256r780169_fix

Configure the system to force a frequent session key renegotiation for SSH connections to the server by adding or modifying the following line in the "/etc/ssh/sshd_config" file: RekeyLimit 1G 1h The SSH daemon must be restarted for the settings to take effect. $ sudo systemctl restart sshd.service

c
The x86 Ctrl-Alt-Delete key sequence must be disabled on OL 8.
CM-6 - High - CCI-000366 - V-248869 - SV-248869r833246_rule
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
OL08-00-040170
Vuln IDs
  • V-248869
Rule IDs
  • SV-248869r833246_rule
A locally logged-on user, who presses Ctrl-Alt-Delete when at the console, can reboot the system. If accidentally pressed, as could happen in the case of a mixed OS environment, this can create the risk of short-term loss of system availability due to unintentional reboot. In a graphical user environment, risk of unintentional reboot from the Ctrl-Alt-Delete sequence is reduced because the user will be prompted before any action is taken.
Checks: C-52303r780171_chk

Verify OL 8 is not configured to reboot the system when Ctrl-Alt-Delete is pressed with the following command: $ sudo systemctl status ctrl-alt-del.target | grep Loaded: Loaded: masked (Reason: Unit ctrl-alt-del.target is masked.) If the "ctrl-alt-del.target" Loaded: value is not set to "masked", this is a finding.

Fix: F-52257r833245_fix

Configure the system to disable the Ctrl-Alt-Delete sequence for the command line with the following commands: $ sudo systemctl disable ctrl-alt-del.target $ sudo systemctl mask ctrl-alt-del.target Created symlink /etc/systemd/system/ctrl-alt-del.target -> /dev/null Reload the daemon to take effect: $ sudo systemctl daemon-reload

c
The x86 Ctrl-Alt-Delete key sequence in OL 8 must be disabled if a graphical user interface is installed.
CM-6 - High - CCI-000366 - V-248870 - SV-248870r780176_rule
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
OL08-00-040171
Vuln IDs
  • V-248870
Rule IDs
  • SV-248870r780176_rule
A locally logged-on user, who presses Ctrl-Alt-Delete, when at the console, can reboot the system. If accidentally pressed, as could happen in the case of a mixed OS environment, this can create the risk of short-term loss of availability of systems due to unintentional reboot. In a graphical user environment, risk of unintentional reboot from the Ctrl-Alt-Delete sequence is reduced because the user will be prompted before any action is taken.
Checks: C-52304r780174_chk

Verify OL 8 is not configured to reboot the system when Ctrl-Alt-Delete is pressed when using a graphical user interface with the following command: $ sudo grep logout /etc/dconf/db/local.d/* logout='' If the "logout" key is bound to an action, is commented out, or is missing, this is a finding.

Fix: F-52258r780175_fix

Configure the system to disable the Ctrl-Alt-Delete sequence when using a graphical user interface by creating or editing the "/etc/dconf/db/local.d/00-disable-CAD" file. Add the setting to disable the Ctrl-Alt-Delete sequence for a graphical user interface: [org/gnome/settings-daemon/plugins/media-keys] logout='' Update the dconf settings: $ sudo dconf update

b
OL 8 must disable the systemd Ctrl-Alt-Delete burst key sequence.
CM-6 - Medium - CCI-000366 - V-248871 - SV-248871r780179_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040172
Vuln IDs
  • V-248871
Rule IDs
  • SV-248871r780179_rule
A locally logged-on user who presses Ctrl-Alt-Delete when at the console can reboot the system. If accidentally pressed, as could happen in the case of a mixed OS environment, this can create the risk of short-term loss of availability of systems due to unintentional reboot. In a graphical user environment, risk of unintentional reboot from the Ctrl-Alt-Delete sequence is reduced because the user will be prompted before any action is taken.
Checks: C-52305r780177_chk

Verify OL 8 is not configured to reboot the system when Ctrl-Alt-Delete is pressed seven times within two seconds with the following command: $ sudo grep -i ctrl /etc/systemd/system.conf CtrlAltDelBurstAction=none If the "CtrlAltDelBurstAction" is not set to "none" or is commented out or missing, this is a finding.

Fix: F-52259r780178_fix

Configure the system to disable the CtrlAltDelBurstAction by added or modifying the following line in the "/etc/systemd/system.conf" configuration file: CtrlAltDelBurstAction=none Reload the daemon for this change to take effect: $ sudo systemctl daemon-reload

a
OL 8 must disable the debug-shell systemd service.
CM-6 - Low - CCI-000366 - V-248872 - SV-248872r780182_rule
RMF Control
CM-6
Severity
Low
CCI
CCI-000366
Version
OL08-00-040180
Vuln IDs
  • V-248872
Rule IDs
  • SV-248872r780182_rule
The debug-shell requires no authentication and provides root privileges to anyone who has physical access to the machine. While this feature is disabled by default, masking it adds a layer of assurance that it will not be enabled via a dependency in "system". This also prevents attackers with physical access from trivially bypassing security on the machine through valid troubleshooting configurations and gaining root access when the system is rebooted.
Checks: C-52306r780180_chk

Verify OL 8 is configured to mask the "debug-shell systemd" service with the following command: $ sudo systemctl status debug-shell.service debug-shell.service Loaded: masked (Reason: Unit debug-shell.service is masked.) Active: inactive (dead) If the "debug-shell.service" is loaded and not masked, this is a finding.

Fix: F-52260r780181_fix

Configure the system to mask the "debug-shell systemd" service with the following command: $ sudo systemctl mask debug-shell.service Created symlink /etc/systemd/system/debug-shell.service -> /dev/null Reload the daemon to take effect: $ sudo systemctl daemon-reload

c
The Trivial File Transfer Protocol (TFTP) server package must not be installed if not required for OL 8 operational support.
CM-6 - High - CCI-000366 - V-248873 - SV-248873r780185_rule
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
OL08-00-040190
Vuln IDs
  • V-248873
Rule IDs
  • SV-248873r780185_rule
If TFTP is required for operational support (such as the transmission of router configurations) its use must be documented with the Information System Security Officer (ISSO), restricted to only authorized personnel, and have access control rules established.
Checks: C-52307r780183_chk

Verify a TFTP server has not been installed on the system with the following command: $ sudo yum list installed tftp-server tftp-server.x86_64 5.2-24.el8 If TFTP is installed and the requirement for TFTP is not documented with the ISSO, this is a finding.

Fix: F-52261r780184_fix

Remove the TFTP package from the system with the following command: $ sudo yum remove tftp-server

c
The root account must be the only account having unrestricted access to the OL 8 system.
CM-6 - High - CCI-000366 - V-248874 - SV-248874r780188_rule
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
OL08-00-040200
Vuln IDs
  • V-248874
Rule IDs
  • SV-248874r780188_rule
If an account other than root also has a User Identifier (UID) of "0", it has root authority, giving that account unrestricted access to the entire operating system. Multiple accounts with a UID of "0" afford an opportunity for potential intruders to guess a password for a privileged account.
Checks: C-52308r780186_chk

Check the system for duplicate UID "0" assignments with the following command: $ sudo awk -F: '$3 == 0 {print $1}' /etc/passwd If any accounts other than root have a UID of "0", this is a finding.

Fix: F-52262r780187_fix

Change the UID of any account on the system, other than root, that has a UID of "0". If the account is associated with system commands or applications, change the UID to one greater than "0" but less than "1000". Otherwise, assign a UID of greater than "1000" that has not already been assigned.

b
OL 8 must prevent IPv4 Internet Control Message Protocol (ICMP) redirect messages from being accepted.
CM-6 - Medium - CCI-000366 - V-248875 - SV-248875r858651_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040209
Vuln IDs
  • V-248875
Rule IDs
  • SV-248875r858651_rule
ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack. The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf
Checks: C-52309r833247_chk

Verify OL 8 will not accept IPv4 ICMP redirect messages. Check the value of the default "accept_redirects" variables with the following command: $ sudo sysctl net.ipv4.conf.default.accept_redirects net.ipv4.conf.default.accept_redirects = 0 If the returned line does not have a value of "0", a line is not returned, or the line is commented out, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo grep -r net.ipv4.conf.default.accept_redirects /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf: net.ipv4.conf.default.accept_redirects = 0 If "net.ipv4.conf.default.accept_redirects" is not set to "0", is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52263r858650_fix

Configure OL 8 to prevent IPv4 ICMP redirect messages from being accepted with the following command: $ sudo sysctl -w net.ipv4.conf.default.accept_redirects=0 Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf If "0" is not the system's default value then add or update the following line in the appropriate file under "/etc/sysctl.d": net.ipv4.conf.default.accept_redirects=0

b
OL 8 must prevent IPv6 Internet Control Message Protocol (ICMP) redirect messages from being accepted.
CM-6 - Medium - CCI-000366 - V-248876 - SV-248876r858653_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040210
Vuln IDs
  • V-248876
Rule IDs
  • SV-248876r858653_rule
ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack. The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf
Checks: C-52310r833249_chk

Verify OL 8 will not accept IPv6 ICMP redirect messages. Note: IPv6 is disabled on the system, this requirement is Not Applicable. Check the value of the default "accept_redirects" variables with the following command: $ sudo sysctl net.ipv6.conf.default.accept_redirects net.ipv6.conf.default.accept_redirects = 0 If the returned line does not have a value of "0", a line is not returned, or the line is commented out, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo grep -r net.ipv6.conf.default.accept_redirects /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf: net.ipv6.conf.default.accept_redirects = 0 If "net.ipv6.conf.default.accept_redirects" is not set to "0", is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52264r858652_fix

Configure OL 8 to prevent IPv6 ICMP redirect messages from being accepted with the following command: $ sudo sysctl -w net.ipv6.conf.default.accept_redirects=0 Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf If "0" is not the system's default value, add or update the following line in "/etc/sysctl.conf" or in the appropriate file under "/etc/sysctl.d": net.ipv6.conf.default.accept_redirects=0

b
OL 8 must not send Internet Control Message Protocol (ICMP) redirects.
CM-6 - Medium - CCI-000366 - V-248877 - SV-248877r858655_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040220
Vuln IDs
  • V-248877
Rule IDs
  • SV-248877r858655_rule
ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages contain information from the system's route table, possibly revealing portions of the network topology. There are notable differences between Internet Protocol version 4 (IPv4) and Internet Protocol version 6 (IPv6). There is only a directive to disable sending of IPv4 redirected packets. Refer to RFC4294 for an explanation of "IPv6 Node Requirements", which resulted in this difference between IPv4 and IPv6. The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf
Checks: C-52311r833251_chk

Verify OL 8 does not send IPv4 ICMP redirect messages. Check the value of the "all send_redirects" variables with the following command: $ sudo sysctl net.ipv4.conf.all.send_redirects net.ipv4.conf.all.send_redirects = 0 If the returned line does not have a value of "0" or a line is not returned, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo grep -r net.ipv4.conf.all.send_redirects /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf: net.ipv4.conf.all.send_redirects = 0 If "net.ipv4.conf.all.send_redirects" is not set to "0", is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52265r858654_fix

Configure OL 8 to not allow interfaces to perform IPv4 ICMP redirects with the following command: $ sudo sysctl -w net.ipv4.conf.all.send_redirects=0 Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf If "0" is not the system's default value, add or update the following line in "/etc/sysctl.conf" or in the appropriate file under "/etc/sysctl.d": net.ipv4.conf.all.send_redirects=0

b
OL 8 must not respond to Internet Control Message Protocol (ICMP) echoes sent to a broadcast address.
CM-6 - Medium - CCI-000366 - V-248878 - SV-248878r858657_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040230
Vuln IDs
  • V-248878
Rule IDs
  • SV-248878r858657_rule
Responding to broadcast ICMP echoes facilitates network mapping and provides a vector for amplification attacks. There are notable differences between Internet Protocol version 4 (IPv4) and Internet Protocol version 6 (IPv6). IPv6 does not implement the same method of broadcast as IPv4. Instead, IPv6 uses multicast addressing to the all-hosts multicast group. Refer to RFC4294 for an explanation of "IPv6 Node Requirements", which resulted in this difference between IPv4 and IPv6. The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf
Checks: C-52312r833253_chk

Verify OL 8 does not respond to ICMP echoes sent to a broadcast address. Check the value of the "icmp_echo_ignore_broadcasts" variable with the following command: $ sudo sysctl net.ipv4.icmp_echo_ignore_broadcasts net.ipv4.icmp_echo_ignore_broadcasts = 1 If the returned line does not have a value of "1", a line is not returned, or the retuned line is commented out, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo grep -r net.ipv4.icmp_echo_ignore_broadcasts /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf: net.ipv4.icmp_echo_ignore_broadcasts = 1 If "net.ipv4.icmp_echo_ignore_broadcasts" is not set to "1", is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52266r858656_fix

Configure OL 8 to not respond to IPv4 ICMP echoes sent to a broadcast address with the following command: $ sudo sysctl -w net.ipv4.icmp_echo_ignore_broadcasts=1 Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf If "1" is not the system's default value, add or update the following line in "/etc/sysctl.conf" or in the appropriate file under "/etc/sysctl.d": net.ipv4.icmp_echo_ignore_broadcasts=1

b
OL 8 must not forward IPv4 source-routed packets.
CM-6 - Medium - CCI-000366 - V-248879 - SV-248879r858659_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040239
Vuln IDs
  • V-248879
Rule IDs
  • SV-248879r858659_rule
Source-routed packets allow the source of the packet to suggest that routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routed traffic, such as when forwarding is enabled and the system is functioning as a router. The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf
Checks: C-52313r833255_chk

Verify OL 8 does not accept IPv4 source-routed packets. Check the value of the accept source route variable with the following command: $ sudo sysctl net.ipv4.conf.all.accept_source_route net.ipv4.conf.all.accept_source_route = 0 If the returned line does not have a value of "0", a line is not returned, or the line is commented out, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo grep -r net.ipv4.conf.all.accept_source_route /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf: net.ipv4.conf.all.accept_source_route = 0 If "net.ipv4.conf.all.accept_source_route" is not set to "0", is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52267r858658_fix

Configure OL 8 to not forward IPv4 source-routed packets with the following command: $ sudo sysctl -w net.ipv4.conf.all.accept_source_route=0 Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf If "0" is not the system's all value then add or update the following line in the appropriate file under "/etc/sysctl.d": net.ipv4.conf.all.accept_source_route=0

b
OL 8 must not forward IPv6 source-routed packets.
CM-6 - Medium - CCI-000366 - V-248880 - SV-248880r858661_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040240
Vuln IDs
  • V-248880
Rule IDs
  • SV-248880r858661_rule
Source-routed packets allow the source of the packet to suggest that routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routed traffic, such as when forwarding is enabled and the system is functioning as a router. The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf
Checks: C-52314r833257_chk

Verify OL 8 does not accept IPv6 source-routed packets. Note: If IPv6 is disabled on the system, this requirement is Not Applicable. Check the value of the accept source route variable with the following command: $ sudo sysctl net.ipv6.conf.all.accept_source_route net.ipv6.conf.all.accept_source_route = 0 If the returned line does not have a value of "0", a line is not returned, or the line is commented out, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo grep -r net.ipv6.conf.all.accept_source_route /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf: net.ipv6.conf.all.accept_source_route = 0 If "net.ipv6.conf.all.accept_source_route" is not set to "0", is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52268r858660_fix

Configure OL 8 to not forward IPv6 source-routed packets with the following command: $ sudo sysctl -w net.ipv6.conf.all.accept_source_route=0 Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf If "0" is not the system's all value then add or update the following line in the appropriate file under "/etc/sysctl.d": net.ipv6.conf.all.accept_source_route=0

b
OL 8 must not forward IPv4 source-routed packets by default.
CM-6 - Medium - CCI-000366 - V-248881 - SV-248881r858663_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040249
Vuln IDs
  • V-248881
Rule IDs
  • SV-248881r858663_rule
Source-routed packets allow the source of the packet to suggest that routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routed traffic, such as when forwarding is enabled and the system is functioning as a router. The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf
Checks: C-52315r833259_chk

Verify OL 8 does not accept IPv4 source-routed packets by default. Check the value of the accept source route variable with the following command: $ sudo sysctl net.ipv4.conf.default.accept_source_route net.ipv4.conf.default.accept_source_route = 0 If the returned line does not have a value of "0", a line is not returned, or the line is commented out, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo grep -r net.ipv4.conf.default.accept_source_route /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf: net.ipv4.conf.default.accept_source_route = 0 If "net.ipv4.conf.default.accept_source_route" is not set to "0", is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52269r858662_fix

Configure OL 8 to not forward IPv4 source-routed packets by default with the following command: $ sudo sysctl -w net.ipv4.conf.default.accept_source_route=0 Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf If "0" is not the system's default value then add or update the following line in the appropriate file under "/etc/sysctl.d": net.ipv4.conf.default.accept_source_route=0

b
OL 8 must not forward IPv6 source-routed packets by default.
CM-6 - Medium - CCI-000366 - V-248882 - SV-248882r858665_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040250
Vuln IDs
  • V-248882
Rule IDs
  • SV-248882r858665_rule
Source-routed packets allow the source of the packet to suggest that routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routed traffic, such as when forwarding is enabled and the system is functioning as a router. The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf
Checks: C-52316r833261_chk

Verify OL 8 does not accept IPv6 source-routed packets by default. Note: If IPv6 is disabled on the system, this requirement is Not Applicable. Check the value of the accept source route variable with the following command: $ sudo sysctl net.ipv6.conf.default.accept_source_route net.ipv6.conf.default.accept_source_route = 0 If the returned line does not have a value of "0", a line is not returned, or the line is commented out, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo grep -r net.ipv6.conf.default.accept_source_route /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf: net.ipv6.conf.default.accept_source_route = 0 If "net.ipv6.conf.default.accept_source_route" is not set to "0", is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52270r858664_fix

Configure OL 8 to not forward IPv6 source-routed packets by default with the following command: $ sudo sysctl -w net.ipv6.conf.default.accept_source_route=0 Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf If "0" is not the system's default value then add or update the following line in the appropriate file under "/etc/sysctl.d": net.ipv6.conf.default.accept_source_route=0

b
OL 8 must not enable IPv6 packet forwarding unless the system is a router.
CM-6 - Medium - CCI-000366 - V-248883 - SV-248883r858669_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040260
Vuln IDs
  • V-248883
Rule IDs
  • SV-248883r858669_rule
Routing protocol daemons are typically used on routers to exchange network topology information with other routers. If this software is used when not required, system network information may be unnecessarily transmitted across the network. The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf
Checks: C-52317r833265_chk

Verify OL 8 is not performing IPv6 packet forwarding unless the system is a router. Note: If IPv6 is disabled on the system, this requirement is Not Applicable. Determine if IPv6 forwarding is disabled using the following commands: $ sudo sysctl net.ipv6.conf.all.forwarding net.ipv6.conf.all.forwarding = 0 If the IPv6 forwarding value is "1" and is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo grep -r net.ipv6.conf.all.forwarding /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf: net.ipv6.conf.all.forwarding = 0 If "net.ipv6.conf.all.forwarding" is not set to "0", is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52271r858668_fix

Configure OL 8 to not allow IPv6 packet forwarding unless the system is a router with the following command: $ sudo sysctl -w net.ipv6.conf.all.forwarding=0 Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf If "0" is not the system's default value, add or update the following lines in "/etc/sysctl.conf" or in the appropriate file under "/etc/sysctl.d": net.ipv6.conf.all.forwarding=0

b
OL 8 must not accept router advertisements on all IPv6 interfaces.
CM-6 - Medium - CCI-000366 - V-248884 - SV-248884r858671_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040261
Vuln IDs
  • V-248884
Rule IDs
  • SV-248884r858671_rule
Routing protocol daemons are typically used on routers to exchange network topology information with other routers. If this software is used when not required, system network information may be unnecessarily transmitted across the network. An illicit router advertisement message could result in a man-in-the-middle attack. The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf
Checks: C-52318r833267_chk

Verify OL 8 does not accept router advertisements on all IPv6 interfaces unless the system is a router. Note: If IPv6 is disabled on the system, this requirement is not applicable. Determine if router advertisements are not accepted by using the following command: $ sudo sysctl net.ipv6.conf.all.accept_ra net.ipv6.conf.all.accept_ra = 0 If the "accept_ra" value is not "0" and is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo grep -r net.ipv6.conf.all.accept_ra /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf: net.ipv6.conf.all.accept_ra = 0 If "net.ipv6.conf.all.accept_ra" is not set to "0", is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52272r858670_fix

Configure the system to not accept router advertisements on all IPv6 interfaces unless the system is a router with the following commands: $ sudo sysctl -w net.ipv6.conf.all.accept_ra=0 Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf If "0" is not the system's default value, add or update the following lines in the appropriate file under "/etc/sysctl.d": net.ipv6.conf.all.accept_ra=0

b
OL 8 must not accept router advertisements on all IPv6 interfaces by default.
CM-6 - Medium - CCI-000366 - V-248885 - SV-248885r858673_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040262
Vuln IDs
  • V-248885
Rule IDs
  • SV-248885r858673_rule
Routing protocol daemons are typically used on routers to exchange network topology information with other routers. If this software is used when not required, system network information may be unnecessarily transmitted across the network. An illicit router advertisement message could result in a man-in-the-middle attack. The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf
Checks: C-52319r833269_chk

Verify OL 8 does not accept router advertisements on all IPv6 interfaces by default, unless the system is a router. Note: If IPv6 is disabled on the system, this requirement is not applicable. Determine if router advertisements are not accepted by using the following command: $ sudo sysctl net.ipv6.conf.default.accept_ra net.ipv6.conf.default.accept_ra = 0 If the "accept_ra" value is not "0" and is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo grep -r net.ipv6.conf.default.accept_ra /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf: net.ipv6.conf.default.accept_ra = 0 If "net.ipv6.conf.default.accept_ra" is not set to "0", is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52273r858672_fix

Configure the system to not accept router advertisements on all IPv6 interfaces by default, unless the system is a router, with the following commands: $ sudo sysctl -w net.ipv6.conf.default.accept_ra=0 Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf If "0" is not the system's default value, add or update the following lines in the appropriate file under "/etc/sysctl.d": net.ipv6.conf.default.accept_ra=0

b
OL 8 must not allow interfaces to perform Internet Control Message Protocol (ICMP) redirects by default.
CM-6 - Medium - CCI-000366 - V-248886 - SV-248886r858675_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040270
Vuln IDs
  • V-248886
Rule IDs
  • SV-248886r858675_rule
ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages contain information from the system's route table, possibly revealing portions of the network topology. There are notable differences between Internet Protocol version 4 (IPv4) and Internet Protocol version 6 (IPv6). There is only a directive to disable sending of IPv4 redirected packets. Refer to RFC4294 for an explanation of "IPv6 Node Requirements", which resulted in this difference between IPv4 and IPv6. The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf
Checks: C-52320r833271_chk

Verify OL 8 does not allow interfaces to perform Internet Protocol version 4 (IPv4) ICMP redirects by default. Check the value of the "default send_redirects" variables with the following command: $ sudo sysctl net.ipv4.conf.default.send_redirects net.ipv4.conf.default.send_redirects=0 If the returned line does not have a value of "0" or a line is not returned, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo grep -r net.ipv4.conf.default.send_redirects /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf: net.ipv4.conf.default.send_redirects = 0 If "net.ipv4.conf.default.send_redirects" is not set to "0", is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52274r858674_fix

Configure OL 8 to not allow interfaces to perform Internet Protocol version 4 (IPv4) ICMP redirects by default with the following command: $ sudo sysctl -w net.ipv4.conf.default.send_redirects=0 Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf If "0" is not the system's default value, add or update the following line in "/etc/sysctl.conf" or in the appropriate file under "/etc/sysctl.d": net.ipv4.conf.default.send_redirects=0

b
OL 8 must ignore IPv4 Internet Control Message Protocol (ICMP) redirect messages.
CM-6 - Medium - CCI-000366 - V-248887 - SV-248887r858677_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040279
Vuln IDs
  • V-248887
Rule IDs
  • SV-248887r858677_rule
ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack. The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf
Checks: C-52321r833273_chk

Verify OL 8 ignores IPv4 ICMP redirect messages. Check the value of the "accept_redirects" variables with the following command: $ sudo sysctl net.ipv4.conf.all.accept_redirects net.ipv4.conf.all.accept_redirects = 0 If the returned line does not have a value of "0", a line is not returned, or the line is commented out, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo grep -r net.ipv4.conf.all.accept_redirects /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf: net.ipv4.conf.all.accept_redirects = 0 If "net.ipv4.conf.all.accept_redirects" is not set to "0", is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52275r858676_fix

Configure OL 8 to ignore IPv4 ICMP redirect messages with the following command: $ sudo sysctl -w net.ipv4.conf.all.accept_redirects=0 Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf If "0" is not the system's default value then add or update the following line in the appropriate file under "/etc/sysctl.d": net.ipv4.conf.all.accept_redirects = 0

b
OL 8 must ignore IPv6 Internet Control Message Protocol (ICMP) redirect messages.
CM-6 - Medium - CCI-000366 - V-248888 - SV-248888r858679_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040280
Vuln IDs
  • V-248888
Rule IDs
  • SV-248888r858679_rule
ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack. The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf
Checks: C-52322r833275_chk

Verify OL 8 ignores IPv6 ICMP redirect messages. Note: If IPv6 is disabled on the system, this requirement is Not Applicable. Check the value of the "accept_redirects" variables with the following command: $ sudo sysctl net.ipv6.conf.all.accept_redirects net.ipv6.conf.all.accept_redirects = 0 If the returned line does not have a value of "0", a line is not returned, or the line is commented out, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo grep -r net.ipv6.conf.all.accept_redirects /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf: net.ipv6.conf.all.accept_redirects = 0 If "net.ipv6.conf.all.accept_redirects" is not set to "0", is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52276r858678_fix

Configure OL 8 to ignore IPv6 ICMP redirect messages with the following command: $ sudo sysctl -w net.ipv6.conf.all.accept_redirects=0 Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf If "0" is not the system's default value then add or update the following line in the appropriate file under "/etc/sysctl.d": net.ipv6.conf.all.accept_redirects = 0

b
OL 8 must disable access to the network "bpf" syscall from unprivileged processes.
CM-6 - Medium - CCI-000366 - V-248889 - SV-248889r858681_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040281
Vuln IDs
  • V-248889
Rule IDs
  • SV-248889r858681_rule
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf
Checks: C-52323r833277_chk

Verify OL 8 prevents privilege escalation through the kernel by disabling access to the "bpf" syscall with the following commands: $ sudo sysctl kernel.unprivileged_bpf_disabled kernel.unprivileged_bpf_disabled = 1 If the returned line does not have a value of "1" or a line is not returned, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo grep -r kernel.unprivileged_bpf_disabled /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf: kernel.unprivileged_bpf_disabled = 1 If "kernel.unprivileged_bpf_disabled" is not set to "1", is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52277r858680_fix

Configure the system to prevent privilege escalation through the kernel by disabling access to the "bpf" syscall by adding the following line to a file in the "/etc/sysctl.d" directory: kernel.unprivileged_bpf_disabled = 1 Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf The system configuration files must be reloaded for the changes to take effect. To reload the contents of the files, run the following command: $ sudo sysctl --system

b
OL 8 must restrict the use of "ptrace" to descendant processes.
CM-6 - Medium - CCI-000366 - V-248890 - SV-248890r858683_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040282
Vuln IDs
  • V-248890
Rule IDs
  • SV-248890r858683_rule
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf
Checks: C-52324r833279_chk

Verify OL 8 restricts the use of "ptrace" to descendant processes with the following commands: $ sudo sysctl kernel.yama.ptrace_scope kernel.yama.ptrace_scope = 1 If the returned line does not have a value of "1" or a line is not returned, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo grep -r kernel.yama.ptrace_scope /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf: kernel.yama.ptrace_scope = 1 If "kernel.yama.ptrace_scope" is not set to "1", is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52278r858682_fix

Configure the system to restrict the use of "ptrace" to descendant processes by adding the following line to a file in the "/etc/sysctl.d" directory: kernel.yama.ptrace_scope = 1 Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf The system configuration files must be reloaded for the changes to take effect. To reload the contents of the files, run the following command: $ sudo sysctl --system

b
OL 8 must restrict exposed kernel pointer addresses access.
CM-6 - Medium - CCI-000366 - V-248891 - SV-248891r858685_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040283
Vuln IDs
  • V-248891
Rule IDs
  • SV-248891r858685_rule
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf
Checks: C-52325r833281_chk

Verify OL 8 restricts exposed kernel pointer addresses access with the following commands: $ sudo sysctl kernel.kptr_restrict kernel.kptr_restrict = 1 If the returned line does not have a value of "1" or "2" or a line is not returned, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo grep -r kernel.kptr_restrict /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf: kernel.kptr_restrict = 1 If "kernel.kptr_restrict" is not set to "1" or "2", is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52279r858684_fix

Configure the system to restrict exposed kernel pointer addresses access by adding the following line to a file in the "/etc/sysctl.d" directory: kernel.kptr_restrict = 1 Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf The system configuration files must be reloaded for the changes to take effect. To reload the contents of the files, run the following command: $ sudo sysctl --system

b
OL 8 must disable the use of user namespaces.
CM-6 - Medium - CCI-000366 - V-248892 - SV-248892r928562_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040284
Vuln IDs
  • V-248892
Rule IDs
  • SV-248892r928562_rule
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. User namespaces are used primarily for Linux containers. "Rootful" containers run with root privileges on the host system and may pose a security risk if compromised. "Rootless" containers run without root privileges and allow for better isolation from the host system. The value "0" disallows the use of user namespaces. When containers are not in use, namespaces should be disallowed. When privileged user namespaces or "rootful" containers are in use, user namespaces should be disallowed. When unprivileged user namespaces or "rootless" containers are deployed on a system, the value should be set to a large non-zero value. The default value depends on the amount of memory in the system, approximately the total memory in kilobytes divided by 256. The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf
Checks: C-52326r928560_chk

Verify OL 8 disables the use of user namespaces with the following commands. Note: If unprivileged user namespaces or "rootless" containers are in use, this requirement is not applicable. $ sudo sysctl user.max_user_namespaces user.max_user_namespaces = 0 If the returned line does not have a value of "0" or a line is not returned, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo grep -r user.max_user_namespaces /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf: user.max_user_namespaces = 0 If "user.max_user_namespaces" is not set to "0", is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52280r928561_fix

Configure the system to disable the use of user namespaces by adding the following line to a file in the "/etc/sysctl.d" directory: user.max_user_namespaces = 0 Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf The system configuration files must be reloaded for the changes to take effect. To reload the contents of the files, run the following command: $ sudo sysctl --system

b
OL 8 must use reverse path filtering on all IPv4 interfaces.
CM-6 - Medium - CCI-000366 - V-248893 - SV-248893r858689_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040285
Vuln IDs
  • V-248893
Rule IDs
  • SV-248893r858689_rule
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Enabling reverse path filtering drops packets with source addresses that are not routable. There is no equivalent filter for IPv6 traffic. The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf
Checks: C-52327r833285_chk

Verify OL 8 uses reverse path filtering on all IPv4 interfaces with the following commands: $ sudo sysctl net.ipv4.conf.all.rp_filter net.ipv4.conf.all.rp_filter = 1 If the returned line does not have a value of "1" or "2" or a line is not returned, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo grep -r net.ipv4.conf.all.rp_filter /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf: net.ipv4.conf.all.rp_filter = 1 If "net.ipv4.conf.all.rp_filter" is not set to "1" or "2", is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52281r858688_fix

Configure the system to use reverse path filtering on all IPv4 interfaces by adding the following line to a file in the "/etc/sysctl.d" directory: net.ipv4.conf.all.rp_filter = 1 Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf The system configuration files must be reloaded for the changes to take effect. To reload the contents of the files, run the following command: $ sudo sysctl --system

b
OL 8 must enable hardening for the Berkeley Packet Filter Just-in-time compiler.
CM-6 - Medium - CCI-000366 - V-248894 - SV-248894r858691_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040286
Vuln IDs
  • V-248894
Rule IDs
  • SV-248894r858691_rule
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Enabling hardening for the Berkeley Packet Filter (BPF) Just-in-time (JIT) compiler aids in mitigating JIT spraying attacks. Setting the value to "2" enables JIT hardening for all users. The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf
Checks: C-52328r833287_chk

Verify OL 8 enables hardening for the BPF JIT with the following commands: $ sudo sysctl net.core.bpf_jit_harden net.core.bpf_jit_harden = 2 If the returned line does not have a value of "2", or a line is not returned, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo grep -r net.core.bpf_jit_harden /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf: net.core.bpf_jit_harden = 2 If "net.core.bpf_jit_harden" is not set to "2", is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52282r858690_fix

Configure OL 8 to enable hardening for the BPF JIT compiler by adding the following line to a file in the "/etc/sysctl.d" directory: net.core.bpf_jit_harden = 2 Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf The system configuration files need to be reloaded for the changes to take effect. To reload the contents of the files, run the following command: $ sudo sysctl --system

b
OL 8 must be configured to prevent unrestricted mail relaying.
CM-6 - Medium - CCI-000366 - V-248895 - SV-248895r780251_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040290
Vuln IDs
  • V-248895
Rule IDs
  • SV-248895r780251_rule
If unrestricted mail relaying is permitted, unauthorized senders could use this host as a mail relay to send spam or for other unauthorized activity.
Checks: C-52329r780249_chk

Verify the system is configured to prevent unrestricted mail relaying. Determine if "postfix" is installed with the following commands: $ sudo yum list installed postfix postfix.x86_64 2:3.3.1-9.el8 If postfix is not installed, this is not applicable. If postfix is installed, determine if it is configured to reject connections from unknown or untrusted networks with the following command: $ sudo postconf -n smtpd_client_restrictions smtpd_client_restrictions = permit_mynetworks, reject If the "smtpd_client_restrictions" parameter contains any entries other than "permit_mynetworks" and "reject", this is a finding.

Fix: F-52283r780250_fix

If "postfix" is installed, modify the "/etc/postfix/main.cf" file to restrict client connections to the local network with the following command: $ sudo postconf -e 'smtpd_client_restrictions = permit_mynetworks,reject'

a
The OL 8 file integrity tool must be configured to verify extended attributes.
CM-6 - Low - CCI-000366 - V-248896 - SV-248896r780254_rule
RMF Control
CM-6
Severity
Low
CCI
CCI-000366
Version
OL08-00-040300
Vuln IDs
  • V-248896
Rule IDs
  • SV-248896r780254_rule
Extended attributes in file systems are used to contain arbitrary data and file metadata with security implications. OL 8 installation media come with a file integrity tool, Advanced Intrusion Detection Environment (AIDE).
Checks: C-52330r780252_chk

Verify the file integrity tool is configured to verify extended attributes. If AIDE is not installed, ask the System Administrator how file integrity checks are performed on the system. Note: AIDE is highly configurable at install time. This requirement assumes the "aide.conf" file is under the "/etc" directory. Use the following command to determine if the file is in another location: $ sudo find / -name aide.conf Check the "aide.conf" file to determine if the "xattrs" rule has been added to the rule list being applied to the files and directories selection lists. An example rule that includes the "xattrs" rule follows: All= p+i+n+u+g+s+m+S+sha512+acl+xattrs+selinux /bin All # apply the custom rule to the files in bin /sbin All # apply the same custom rule to the files in sbin If the "xattrs" rule is not being used on all uncommented selection lines in the "/etc/aide.conf" file, or extended attributes are not being checked by another file integrity tool, this is a finding.

Fix: F-52284r780253_fix

Configure the file integrity tool to check file and directory extended attributes. If AIDE is installed, ensure the "xattrs" rule is present on all uncommented file and directory selection lists.

a
The OL 8 file integrity tool must be configured to verify Access Control Lists (ACLs).
CM-6 - Low - CCI-000366 - V-248897 - SV-248897r880561_rule
RMF Control
CM-6
Severity
Low
CCI
CCI-000366
Version
OL08-00-040310
Vuln IDs
  • V-248897
Rule IDs
  • SV-248897r880561_rule
ACLs can provide permissions beyond those permitted through the file mode and must be verified by file integrity tools. OL 8 installation media come with a file integrity tool, Advanced Intrusion Detection Environment (AIDE).
Checks: C-52331r880560_chk

Verify the file integrity tool is configured to verify ACLs. Use the following command to determine if the file is in a location other than "/etc/aide/aide.conf": $ sudo find / -name aide.conf Check the "aide.conf" file to determine if the "acl" rule has been added to the rule list being applied to the files and directories selection lists with the following command: $ sudo grep -E "[+]?acl" /etc/aide.conf VarFile = OwnerMode+n+l+X+acl If the "acl" rule is not being used on all selection lines in the "/etc/aide.conf" file or is commented out, or ACLs are not being checked by another file integrity tool, this is a finding.

Fix: F-52285r780256_fix

Configure the file integrity tool to check file and directory ACLs. If AIDE is installed, ensure the "acl" rule is present on all file and directory selection lists.

b
The graphical display manager must not be installed on OL 8 unless approved.
CM-6 - Medium - CCI-000366 - V-248898 - SV-248898r780260_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040320
Vuln IDs
  • V-248898
Rule IDs
  • SV-248898r780260_rule
Internet services that are not required for system or application processes must not be active to decrease the attack surface of the system. X Windows has a long history of security vulnerabilities and will not be used unless approved and documented.
Checks: C-52332r780258_chk

Verify that if the system has a display server installed, it is authorized. Check for the display server package with the following example command: $ sudo rpm -qa | grep xorg | grep server Ask the System Administrator if use of the display server is an operational requirement. If the use of a display server on the system is not documented with the Information System Security Officer (ISSO), this is a finding.

Fix: F-52286r780259_fix

Document the requirement for a display server with the ISSO or remove the related packages with the following example command: $ sudo rpm -e xorg-x11-server-common

b
OL 8 network interfaces must not be in promiscuous mode.
CM-6 - Medium - CCI-000366 - V-248899 - SV-248899r780263_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040330
Vuln IDs
  • V-248899
Rule IDs
  • SV-248899r780263_rule
Network interfaces in promiscuous mode allow for the capture of all network traffic visible to the system. If unauthorized individuals can access these applications, it may allow them to collect information such as logon IDs, passwords, and key exchanges between systems. If the system is being used to perform a network troubleshooting function, the use of these tools must be documented with the Information System Security Officer (ISSO) and restricted to only authorized personnel.
Checks: C-52333r780261_chk

Verify network interfaces are not in promiscuous mode unless approved by the ISSO and documented. Check for the status with the following command: $ sudo ip link | grep -i promisc If network interfaces are found on the system in promiscuous mode and their use has not been approved by the ISSO and documented, this is a finding.

Fix: F-52287r780262_fix

Configure network interfaces to turn off promiscuous mode unless approved by the ISSO and documented. Set the promiscuous mode of an interface to "off" with the following command: $ sudo ip link set dev <devicename> multicast off promisc off

b
OL 8 remote X connections for interactive users must be disabled unless to fulfill documented and validated mission requirements.
CM-6 - Medium - CCI-000366 - V-248900 - SV-248900r858588_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040340
Vuln IDs
  • V-248900
Rule IDs
  • SV-248900r858588_rule
The security risk of using X11 forwarding is that the client's X11 display server may be exposed to attack when the SSH client requests forwarding. A System Administrator may have a stance in which they want to protect clients that may expose themselves to attack by unwittingly requesting X11 forwarding, which can warrant a "no" setting. X11 forwarding should be enabled with caution. Users with the ability to bypass file permissions on the remote host (for the user's X11 authorization database) can access the local X11 display through the forwarded connection. An attacker may then be able to perform activities such as keystroke monitoring if the "ForwardX11Trusted" option is also enabled. If X11 services are not required for the system's intended function, they should be disabled or restricted as appropriate to the system’s needs.
Checks: C-52334r858587_chk

Verify "X11Forwarding" is disabled with the following command: $ sudo grep -ir x11forwarding /etc/ssh/sshd_config* | grep -v "^#" X11Forwarding no If the "X11Forwarding" keyword is set to "yes" and is not documented with the Information System Security Officer (ISSO) as an operational requirement or is missing, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52288r780265_fix

Edit the "/etc/ssh/sshd_config" file to uncomment or add the line for the "X11Forwarding" keyword and set its value to "no" (this file may be named differently or be in a different location if using a version of SSH that is provided by a third-party vendor): X11Forwarding no The SSH service must be restarted for changes to take effect: $ sudo systemctl restart sshd

b
The OL 8 SSH daemon must prevent remote hosts from connecting to the proxy display.
CM-6 - Medium - CCI-000366 - V-248901 - SV-248901r858590_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040341
Vuln IDs
  • V-248901
Rule IDs
  • SV-248901r858590_rule
When X11 forwarding is enabled, there may be additional exposure to the server and client displays if the sshd proxy display is configured to listen on the wildcard address. By default, sshd binds the forwarding server to the loopback address and sets the hostname part of the DISPLAY environment variable to localhost. This prevents remote hosts from connecting to the proxy display.
Checks: C-52335r858589_chk

Verify the OL 8 SSH daemon prevents remote hosts from connecting to the proxy display. Check the SSH "X11UseLocalhost" setting with the following command: $ sudo grep -ir x11uselocalhost /etc/ssh/sshd_config* X11UseLocalhost yes If the "X11UseLocalhost" keyword is set to "no", is missing, or is commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-52289r780268_fix

Configure the OL 8 SSH daemon to prevent remote hosts from connecting to the proxy display. Edit the "/etc/ssh/sshd_config" file to uncomment or add the line for the "X11UseLocalhost" keyword and set its value to "yes" (this file may be named differently or be in a different location if using a version of SSH that is provided by a third-party vendor): X11UseLocalhost yes

b
If the Trivial File Transfer Protocol (TFTP) server is required, the OL 8 TFTP daemon must be configured to operate in secure mode.
CM-6 - Medium - CCI-000366 - V-248902 - SV-248902r780272_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040350
Vuln IDs
  • V-248902
Rule IDs
  • SV-248902r780272_rule
Restricting TFTP to a specific directory prevents remote users from copying, transferring, or overwriting system files.
Checks: C-52336r780270_chk

Verify the TFTP daemon is configured to operate in secure mode with the following commands: $ sudo yum list installed tftp-server tftp-server.x86_64 x.x-x.el8 If a TFTP server is not installed, this is not applicable. If a TFTP server is installed, check for the server arguments with the following command: $ sudo grep server_args /etc/xinetd.d/tftp server_args = -s /var/lib/tftpboot If the "server_args" line does not have a "-s" option and a subdirectory is not assigned, this is a finding.

Fix: F-52290r780271_fix

Configure the TFTP daemon to operate in secure mode by adding the following line to "/etc/xinetd.d/tftp" (or modify the line to have the required value): server_args = -s /var/lib/tftpboot

c
A File Transfer Protocol (FTP) server package must not be installed unless mission essential on OL 8.
CM-6 - High - CCI-000366 - V-248903 - SV-248903r780275_rule
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
OL08-00-040360
Vuln IDs
  • V-248903
Rule IDs
  • SV-248903r780275_rule
The FTP service provides an unencrypted remote access that does not provide for the confidentiality and integrity of user passwords or the remote session. If a privileged user were to log on using this service, the privileged user password could be compromised. SSH or other encrypted file transfer methods must be used in place of this service.
Checks: C-52337r780273_chk

Verify an FTP server has not been installed on the system with the following commands: $ sudo yum list installed | grep ftpd vsftpd-3.0.3.el8.x86_64.rpm If an FTP server is installed and is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding.

Fix: F-52291r780274_fix

Document the FTP server package with the ISSO as an operational requirement or remove it from the system with the following command: $ sudo yum remove vsftpd

b
OL 8 must not have the "gssproxy" package installed if not required for operational support.
CM-6 - Medium - CCI-000366 - V-248904 - SV-248904r780278_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040370
Vuln IDs
  • V-248904
Rule IDs
  • SV-248904r780278_rule
Verify the operating system is configured to disable non-essential capabilities. The most secure way of ensuring a non-essential capability is disabled is to not have the capability installed. When an application uses Generic Security Services API (GSSAPI), typically it will have direct access to its security credentials, and all cryptographic operations are performed in the application's process. This is undesirable, but "gssproxy" can help in almost all use cases. It provides privilege separation to applications using the GSSAPI: The gssproxy daemon runs on the system, holds the application's credentials, and performs operations on behalf of the application.
Checks: C-52338r780276_chk

Determine if the "gssproxy" package is installed with the following command: $ sudo yum list installed gssproxy If the "gssproxy" package is installed, this is a finding.

Fix: F-52292r780277_fix

Configure OL 8 to disable non-essential capabilities by removing the "gssproxy" package from the system with the following command: $ sudo yum remove gssproxy

b
OL 8 must not have the "iprutils" package installed if not required for operational support.
CM-6 - Medium - CCI-000366 - V-248905 - SV-248905r780281_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040380
Vuln IDs
  • V-248905
Rule IDs
  • SV-248905r780281_rule
The "iprutils" package provides a suite of utilities to manage and configure IBM Power Linux RAID Adapters supported by the IPR SCSI storage device driver. Disabling the "iprutils" package protects the system against exploitation of any flaws in its implementation.
Checks: C-52339r780279_chk

Determine if the "iprutils" package is installed with the following command: $ sudo yum list installed iprutils If the "iprutils" package is installed, this is a finding.

Fix: F-52293r780280_fix

Configure OL 8 to disable non-essential capabilities by removing the "iprutils" package from the system with the following command: $ sudo yum remove iprutils

b
OL 8 must not have the "tuned" package installed if not required for operational support.
CM-6 - Medium - CCI-000366 - V-248906 - SV-248906r780284_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040390
Vuln IDs
  • V-248906
Rule IDs
  • SV-248906r780284_rule
"Tuned" is a daemon that uses "udev" to monitor connected devices and statically and dynamically tunes system settings according to a selected profile. Disabling the "tuned" package protects the system against exploitation of any flaws in its implementation.
Checks: C-52340r780282_chk

Determine if the "tuned" package is installed with the following command: $ sudo yum list installed tuned If the "tuned" package is installed, this is a finding.

Fix: F-52294r780283_fix

Configure OL 8 to disable non-essential capabilities by removing the "tuned" package from the system with the following command: $ sudo yum remove tuned

b
OL 8 must prevent nonprivileged users from executing privileged functions, including disabling, circumventing, or altering implemented security safeguards/countermeasures.
AC-6 - Medium - CCI-002235 - V-248907 - SV-248907r928804_rule
RMF Control
AC-6
Severity
Medium
CCI
CCI-002235
Version
OL08-00-040400
Vuln IDs
  • V-248907
Rule IDs
  • SV-248907r928804_rule
Preventing nonprivileged users from executing privileged functions mitigates the risk that unauthorized individuals or processes may gain unnecessary access to information or privileges. Privileged functions include, for example, establishing accounts, performing system integrity checks, or administering cryptographic key management activities. Nonprivileged users are individuals who do not possess appropriate authorizations. Circumventing intrusion detection and prevention mechanisms or malicious code protection mechanisms are examples of privileged functions that require protection from nonprivileged users.
Checks: C-52341r928563_chk

Verify the operating system prevents nonprivileged users from executing privileged functions, including disabling, circumventing, or altering implemented security safeguards/countermeasures. Obtain a list of authorized users (other than system administrator and guest accounts) for the system. Check the list against the system by using the following command: $ sudo semanage login -l | more Login Name SELinux User MLS/MCS Range Service __default__ user_u s0-s0:c0.c1023 * root unconfined_u s0-s0:c0.c1023 * system_u system_u s0-s0:c0.c1023 * joe staff_u s0-s0:c0.c1023 * All administrators must be mapped to the "sysadm_u", "staff_u", or an appropriately tailored confined role as defined by the organization. All authorized nonadministrative users must be mapped to the "user_u" role. If they are not mapped in this way, this is a finding.

Fix: F-52295r928804_fix

Configure OL 8 to prevent nonprivileged users from executing privileged functions, including disabling, circumventing, or altering implemented security safeguards/countermeasures. Use the following command to map a new user to the "sysadm_u" role: $ sudo semanage login -a -s sysadm_u <username> Use the following command to map an existing user to the "sysadm_u" role: $ sudo semanage login -m -s sysadm_u <username> Use the following command to map a new user to the "staff_u" role: $ sudo semanage login -a -s staff_u <username> Use the following command to map an existing user to the "staff_u" role: $ sudo semanage login -m -s staff_u <username> Use the following command to map a new user to the "user_u" role: $ sudo semanage login -a -s user_u <username> Use the following command to map an existing user to the "user_u" role: $ sudo semanage login -m -s user_u <username> Note: SELinux confined users mapped to sysadm_u are not allowed to log in to the system over SSH, by default. If this is a required function, it can be configured by setting the ssh_sysadm_login SELinux boolean to "on" with the following command: $ sudo setsebool -P ssh_sysadm_login on This must be documented with the information system security officer (ISSO) as an operational requirement.

c
The OL 8 operating system must not have accounts configured with blank or null passwords.
CM-6 - High - CCI-000366 - V-252650 - SV-252650r818746_rule
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
OL08-00-010121
Vuln IDs
  • V-252650
Rule IDs
  • SV-252650r818746_rule
If an account has an empty password, anyone could log on and run commands with the privileges of that account. Accounts with empty passwords should never be used in operational environments.
Checks: C-56106r818744_chk

Check the "/etc/shadow" file for blank passwords with the following command: $ sudo awk -F: '!$2 {print $1}' /etc/shadow If the command returns any results, this is a finding.

Fix: F-56056r818745_fix

Configure all accounts on the system to have a password or lock the account with the following commands: Perform a password reset: $ sudo passwd [username] Lock an account: $ sudo passwd -l [username]

b
OL 8 library directories must have mode 755 or less permissive.
CM-5 - Medium - CCI-001499 - V-252651 - SV-252651r818749_rule
RMF Control
CM-5
Severity
Medium
CCI
CCI-001499
Version
OL08-00-010331
Vuln IDs
  • V-252651
Rule IDs
  • SV-252651r818749_rule
If OL 8 were to allow any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to OL 8 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges. Only qualified and authorized individuals will be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications.
Checks: C-56107r818747_chk

Verify the system-wide shared library directories within "/lib", "/lib64", "/usr/lib" and "/usr/lib64" have mode "755" or less permissive with the following command: $ sudo find /lib /lib64 /usr/lib /usr/lib64 -perm /022 -type d -exec stat -c "%n %a" '{}' \; If any system-wide shared library directories are found to be group-writable or world-writable, this is a finding.

Fix: F-56057r818748_fix

Configure the library directories to be protected from unauthorized access. Run the following command, replacing "[DIRECTORY]" with any library directory with a mode more permissive than 755. $ sudo chmod 755 [DIRECTORY]

b
OL 8 library directories must be owned by root.
CM-5 - Medium - CCI-001499 - V-252652 - SV-252652r818752_rule
RMF Control
CM-5
Severity
Medium
CCI
CCI-001499
Version
OL08-00-010341
Vuln IDs
  • V-252652
Rule IDs
  • SV-252652r818752_rule
If OL 8 were to allow any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to OL 8 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges. Only qualified and authorized individuals will be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications.
Checks: C-56108r818750_chk

Verify the system-wide shared library directories are owned by "root" with the following command: $ sudo find /lib /lib64 /usr/lib /usr/lib64 ! -user root -type d -exec stat -c "%n %U" '{}' \; If any system wide shared library directory is returned, this is a finding.

Fix: F-56058r818751_fix

Configure the system-wide shared library directories within (/lib, /lib64, /usr/lib and /usr/lib64) to be protected from unauthorized access. Run the following command, replacing "[DIRECTORY]" with any library directory not owned by "root". $ sudo chown root [DIRECTORY]

b
OL 8 library directories must be group-owned by root or a system account.
CM-5 - Medium - CCI-001499 - V-252653 - SV-252653r818755_rule
RMF Control
CM-5
Severity
Medium
CCI
CCI-001499
Version
OL08-00-010351
Vuln IDs
  • V-252653
Rule IDs
  • SV-252653r818755_rule
If OL 8 were to allow any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to OL 8 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges. Only qualified and authorized individuals will be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications.
Checks: C-56109r818753_chk

Verify the system-wide shared library directories are group-owned by "root" with the following command: $ sudo find /lib /lib64 /usr/lib /usr/lib64 ! -group root -type d -exec stat -c "%n %G" '{}' \; If any system wide shared library directory is returned and is not group-owned by a required system account, this is a finding.

Fix: F-56059r818754_fix

Configure the system-wide shared library directories (/lib, /lib64, /usr/lib and /usr/lib64) to be protected from unauthorized access. Run the following command, replacing "[DIRECTORY]" with any library directory not group-owned by "root". $ sudo chgrp root [DIRECTORY]

b
The OL 8 operating system must use a file integrity tool to verify correct operation of all security functions.
SI-6 - Medium - CCI-002696 - V-252654 - SV-252654r880573_rule
RMF Control
SI-6
Severity
Medium
CCI
CCI-002696
Version
OL08-00-010359
Vuln IDs
  • V-252654
Rule IDs
  • SV-252654r880573_rule
Without verification of the security functions, security functions may not operate correctly, and the failure may go unnoticed. Security function is defined as the hardware, software, and/or firmware of the information system responsible for enforcing the system security policy and supporting the isolation of code and data on which the protection is based. Security functionality includes, but is not limited to, establishing system accounts, configuring access authorizations (i.e., permissions, privileges), setting events to be audited, and setting intrusion detection parameters. This requirement applies to the OL 8 operating system performing security function verification/testing and/or systems and environments that require this functionality.
Checks: C-56110r880571_chk

Verify that Advanced Intrusion Detection Environment (AIDE) is installed and verifies the correct operation of all security functions. Check that the AIDE package is installed with the following command: $ sudo rpm -q aide aide-0.16-14.el8_5.1.x86_64 If AIDE is not installed, ask the System Administrator how file integrity checks are performed on the system. If there is no application installed to perform integrity checks, this is a finding. If AIDE is installed, check if it has been initialized with the following command: $ sudo /usr/sbin/aide --check If the output is "Couldn't open file /var/lib/aide/aide.db.gz for reading", this is a finding.

Fix: F-56060r880572_fix

Install AIDE, initialize it, and perform a manual check. Install AIDE: $ sudo yum install aide Initialize it: $ sudo /usr/sbin/aide --init Example output: Number of entries: 48623 --------------------------------------------------- The attributes of the (uncompressed) database(s): --------------------------------------------------- /var/lib/aide/aide.db.new.gz SHA1 : LTAVQ8tFJthsrf4m9gfRpnf1vyc= SHA256 : NJ9+uzRQKSwmLQ8A6IpKNvYjVKGbhSjt BeJBVcmOVrI= SHA512 : 7d8I/F6A1b07E4ZuGeilZjefRgJJ/F20 eC2xoag1OsOVpctt3Mi7Jjjf3vFW4xoY 5mdS6/ImQpm0xtlTLOPeQQ== End timestamp: 2022-10-20 10:50:52 -0700 (run time: 0m 46s) The new database will need to be renamed to be read by AIDE: $ sudo mv /var/lib/aide/aide.db.new.gz /var/lib/aide/aide.db.gz Perform a manual check: $ sudo /usr/sbin/aide --check Example output: Start timestamp: 2022-10-20 11:03:16 -0700 (AIDE 0.16) AIDE found differences between database and filesystem!! ... Done.

b
OL 8 must specify the default "include" directory for the /etc/sudoers file.
CM-6 - Medium - CCI-000366 - V-252655 - SV-252655r880549_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010379
Vuln IDs
  • V-252655
Rule IDs
  • SV-252655r880549_rule
The "sudo" command allows authorized users to run programs (including shells) as other users, system users, and root. The "/etc/sudoers" file is used to configure authorized "sudo" users as well as the programs they are allowed to run. Some configuration options in the "/etc/sudoers" file allow configured users to run programs without re-authenticating. Use of these configuration options makes it easier for one compromised account to be used to compromise other accounts. It is possible to include other sudoers files from within the sudoers file currently being parsed using the #include and #includedir directives. When sudo reaches this line it will suspend processing of the current file (/etc/sudoers) and switch to the specified file/directory. Once the end of the included file(s) are reached, the rest of /etc/sudoers will be processed. Files that are included may themselves include other files. A hard limit of 128 nested include files is enforced to prevent include file loops.
Checks: C-56111r880547_chk

Note: If the "include" and "includedir" directives are not present in the /etc/sudoers file, this requirement is not applicable. Verify the operating system specifies only the default "include" directory for the /etc/sudoers file with the following command: $ sudo grep include /etc/sudoers #includedir /etc/sudoers.d If the results are not "/etc/sudoers.d" or additional files or directories are specified, this is a finding. Verify the operating system does not have nested "include" files or directories within the /etc/sudoers.d directory with the following command: $ sudo grep -Er include /etc/sudoers.d If results are returned, this is a finding.

Fix: F-56061r880548_fix

Configure the /etc/sudoers file to only include the /etc/sudoers.d directory. Edit the /etc/sudoers file with the following command: $ sudo visudo Add or modify the following line: #includedir /etc/sudoers.d

b
The OL 8 operating system must not be configured to bypass password requirements for privilege escalation.
IA-11 - Medium - CCI-002038 - V-252656 - SV-252656r854184_rule
RMF Control
IA-11
Severity
Medium
CCI
CCI-002038
Version
OL08-00-010385
Vuln IDs
  • V-252656
Rule IDs
  • SV-252656r854184_rule
Without re-authentication, users may access resources or perform tasks for which they do not have authorization. When operating systems provide the capability to escalate a functional capability, it is critical the user re-authenticate. Satisfies: SRG-OS-000373-GPOS-00156, SRG-OS-000373-GPOS-00157, SRG-OS-000373-GPOS-00158
Checks: C-56112r818762_chk

Verify the operating system is not be configured to bypass password requirements for privilege escalation. Check the configuration of the "/etc/pam.d/sudo" file with the following command: $ sudo grep pam_succeed_if /etc/pam.d/sudo If any occurrences of "pam_succeed_if" is returned from the command, this is a finding.

Fix: F-56062r818763_fix

Configure the operating system to require users to supply a password for privilege escalation. Check the configuration of the "/etc/ pam.d/sudo" file with the following command: $ sudo vi /etc/pam.d/sudo Remove any occurrences of " pam_succeed_if " in the file.

b
OL 8 must ensure the password complexity module is enabled in the system-auth file.
CM-6 - Medium - CCI-000366 - V-252657 - SV-252657r902812_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-020101
Vuln IDs
  • V-252657
Rule IDs
  • SV-252657r902812_rule
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. "pwquality" enforces complex password construction configuration and has the ability to limit brute-force attacks on the system. OL 8 utilizes "pwquality" as a mechanism to enforce password complexity. This is set in both: /etc/pam.d/password-auth /etc/pam.d/system-auth
Checks: C-56113r902810_chk

Verify the operating system uses "pwquality" to enforce the password complexity rules. Check for the use of "pwquality" in the system-auth file with the following command: $ sudo cat /etc/pam.d/system-auth | grep pam_pwquality password requisite pam_pwquality.so If the command does not return a line containing the value "pam_pwquality.so" as shown, or the line is commented out, this is a finding.

Fix: F-56063r902811_fix

Configure the operating system to use "pwquality" to enforce password complexity rules. Add the following line to the "/etc/pam.d/system-auth" file (or modify the line to have the required value): password requisite pam_pwquality.so

b
OL 8 systems below version 8.4 must ensure the password complexity module in the system-auth file is configured for three retries or less.
CM-6 - Medium - CCI-000366 - V-252658 - SV-252658r902815_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-020102
Vuln IDs
  • V-252658
Rule IDs
  • SV-252658r902815_rule
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. "pwquality" enforces complex password construction configuration and has the ability to limit brute-force attacks on the system. OL 8 utilizes "pwquality" as a mechanism to enforce password complexity. This is set in both: /etc/pam.d/password-auth /etc/pam.d/system-auth By limiting the number of attempts to meet the pwquality module complexity requirements before returning with an error, the system will audit abnormal attempts at password changes.
Checks: C-56114r902813_chk

Note: This requirement applies to OL versions 8.0 through 8.3. If the system is OL version 8.4 or newer, this requirement is not applicable. Verify the operating system is configured to limit the "pwquality" retry option to 3. Check for the use of the "pwquality" retry option in the system-auth file with the following command: $ sudo cat /etc/pam.d/system-auth | grep pam_pwquality password requisite pam_pwquality.so retry=3 If the value of "retry" is set to "0" or greater than "3", this is a finding.

Fix: F-56064r902814_fix

Configure the operating system to limit the "pwquality" retry option to 3. Add the following line to the "/etc/pam.d/system-auth" file (or modify the line to have the required value): password requisite pam_pwquality.so retry=3

b
OL 8 systems below version 8.4 must ensure the password complexity module in the password-auth file is configured for three retries or less.
CM-6 - Medium - CCI-000366 - V-252659 - SV-252659r902818_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-020103
Vuln IDs
  • V-252659
Rule IDs
  • SV-252659r902818_rule
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. "pwquality" enforces complex password construction configuration and has the ability to limit brute-force attacks on the system. OL 8 utilizes "pwquality" as a mechanism to enforce password complexity. This is set in both: /etc/pam.d/password-auth /etc/pam.d/system-auth By limiting the number of attempts to meet the pwquality module complexity requirements before returning with an error, the system will audit abnormal attempts at password changes.
Checks: C-56115r902816_chk

Note: This requirement applies to OL versions 8.0 through 8.3. If the system is OL version 8.4 or newer, this requirement is not applicable. Verify the operating system is configured to limit the "pwquality" retry option to 3. Check for the use of the "pwquality" retry option in the password-auth file with the following command: $ sudo cat /etc/pam.d/password-auth | grep pam_pwquality password requisite pam_pwquality.so retry=3 If the value of "retry" is set to "0" or greater than "3", this is a finding.

Fix: F-56065r902817_fix

Configure the operating system to limit the "pwquality" retry option to 3. Add the following line to the "/etc/pam.d/password-auth" file (or modify the line to have the required value): password requisite pam_pwquality.so retry=3

b
OL 8 systems, version 8.4 and above, must ensure the password complexity module is configured for three retries or less.
CM-6 - Medium - CCI-000366 - V-252660 - SV-252660r858600_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-020104
Vuln IDs
  • V-252660
Rule IDs
  • SV-252660r858600_rule
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. "pwquality" enforces complex password construction configuration and has the ability to limit brute-force attacks on the system. OL 8 utilizes "pwquality" as a mechanism to enforce password complexity. This is set in both: /etc/pam.d/password-auth /etc/pam.d/system-auth By limiting the number of attempts to meet the pwquality module complexity requirements before returning with an error, the system will audit abnormal attempts at password changes.
Checks: C-56116r858598_chk

Note: This requirement applies to OL versions 8.4 or newer. If the system is OL below version 8.4, this requirement is not applicable. Verify the operating system is configured to limit the "pwquality" retry option to 3. Check for the use of the "pwquality" retry option with the following command: $ sudo grep -r retry /etc/security/pwquality.conf* /etc/security/pwquality.conf:retry = 3 If the value of "retry" is set to "0" or greater than "3", is commented out or missing, this is a finding. If conflicting results are returned, this is a finding. Check for the use of the "pwquality" retry option in the system-auth and password-auth files with the following command: $ sudo grep pwquality /etc/pam.d/system-auth /etc/pam.d/password-auth | grep retry If the command returns any results, this is a finding.

Fix: F-56066r858599_fix

Configure the operating system to limit the "pwquality" retry option to 3. Add the following line to the "/etc/security/pwquality.conf" file(or modify the line to have the required value): retry = 3 Remove any configurations that conflict with the above value.

b
OL 8 must be configured in the system-auth file to prohibit password reuse for a minimum of five generations.
IA-5 - Medium - CCI-000200 - V-252661 - SV-252661r902824_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000200
Version
OL08-00-020221
Vuln IDs
  • V-252661
Rule IDs
  • SV-252661r902824_rule
Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. If the information system or application allows the user to reuse their password consecutively when that password has exceeded its defined lifetime, the end result is a password that is not changed per policy requirements. OL 8 utilizes "pwhistory" consecutively as a mechanism to prohibit password reuse. This is set in both: /etc/pam.d/password-auth /etc/pam.d/system-auth Note that manual changes to the listed files may be overwritten by the "authselect" program.
Checks: C-56117r902822_chk

Verify the operating system is configured in the system-auth file to prohibit password reuse for a minimum of five generations. Check for the value of the "remember" argument in "/etc/pam.d/system-auth" with the following command: $ sudo grep -i remember /etc/pam.d/system-auth password requisite pam_pwhistory.so use_authtok remember=5 retry=3 If the line containing "pam_pwhistory.so" does not have the "remember" module argument set, is commented out, or the value of the "remember" module argument is set to less than "5", this is a finding.

Fix: F-56067r902823_fix

Configure the operating system in the system-auth file to prohibit password reuse for a minimum of five generations. Add the following line in "/etc/pam.d/system-auth" (or modify the line to have the required value): password requisite pam_pwhistory.so use_authtok remember=5 retry=3

b
OL 8 must not enable IPv4 packet forwarding unless the system is a router.
CM-6 - Medium - CCI-000366 - V-252662 - SV-252662r858667_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040259
Vuln IDs
  • V-252662
Rule IDs
  • SV-252662r858667_rule
Routing protocol daemons are typically used on routers to exchange network topology information with other routers. If this software is used when not required, system network information may be unnecessarily transmitted across the network. The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf
Checks: C-56118r833263_chk

Verify OL 8 is not performing IPv4 packet forwarding, unless the system is a router. Check that IPv4 forwarding is disabled using the following command: $ sudo sysctl net.ipv4.conf.all.forwarding net.ipv4.conf.all.forwarding = 0 If the IPv4 forwarding value is not "0" and is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding. Check that the configuration files are present to enable this network parameter: $ sudo grep -r net.ipv4.conf.all.forwarding /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf: net.ipv4.conf.all.forwarding = 0 If "net.ipv4.conf.all.forwarding" is not set to "0", is missing or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix: F-56068r858666_fix

Configure OL 8 to not allow IPv4 packet forwarding unless the system is a router. Add or edit the following line in a system configuration file, in the "/etc/sysctl.d/" directory: net.ipv4.conf.all.forwarding=0 Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf Load settings from all system configuration files with the following command: $ sudo sysctl --system

b
The graphical display manager must not be the default target on OL 8 unless approved.
CM-6 - Medium - CCI-000366 - V-252663 - SV-252663r818785_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040321
Vuln IDs
  • V-252663
Rule IDs
  • SV-252663r818785_rule
Internet services that are not required for system or application processes must not be active to decrease the attack surface of the system. Graphical display managers have a long history of security vulnerabilities and must not be used, unless approved and documented.
Checks: C-56119r818783_chk

Verify that the system is configured to boot to the command line: $ systemctl get-default multi-user.target If the system default target is not set to "multi-user.target" and the Information System Security Officer (ISSO) lacks a documented requirement for a graphical user interface, this is a finding.

Fix: F-56069r818784_fix

Document the requirement for a graphical user interface with the ISSO or reinstall the operating system without the graphical user interface. If reinstallation is not feasible, then continue with the following procedure: Open an SSH session and enter the following commands: $ sudo systemctl set-default multi-user.target A reboot is required for the changes to take effect.

b
OL 8 SSH server must be configured to use only FIPS-validated key exchange algorithms.
AC-17 - Medium - CCI-001453 - V-255898 - SV-255898r917916_rule
RMF Control
AC-17
Severity
Medium
CCI
CCI-001453
Version
OL08-00-040342
Vuln IDs
  • V-255898
Rule IDs
  • SV-255898r917916_rule
Without cryptographic integrity protections provided by FIPS-validated cryptographic algorithms, information can be viewed and altered by unauthorized users without detection. OL 8 incorporates system-wide crypto policies by default. The SSH configuration file has no effect on the ciphers, MACs, or algorithms unless specifically defined in the /etc/sysconfig/sshd file. The employed algorithms can be viewed in the /etc/crypto-policies/back-ends/opensshserver.config file. The system will attempt to use the first algorithm presented by the client that matches the server list. Listing the values "strongest to weakest" is a method to ensure the use of the strongest algorithm available to secure the SSH connection.
Checks: C-59575r917915_chk

Verify that the SSH server is configured to use only FIPS-validated key exchange algorithms: $ sudo grep -i kexalgorithms /etc/crypto-policies/back-ends/opensshserver.config CRYPTO_POLICY='-oKexAlgorithms=ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512' If the entries following "KexAlgorithms" have any algorithms defined other than "ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512", appear in a different order than shown, or are missing or commented out, this is a finding.

Fix: F-59518r880543_fix

Configure the SSH server to use only FIPS-validated key exchange algorithms by adding or modifying the following line in "/etc/crypto-policies/back-ends/opensshserver.config": -oKexAlgorithms=ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512 A reboot is required for the changes to take effect.

b
OL 8 must ensure cryptographic verification of vendor software packages.
CM-5 - Medium - CCI-001749 - V-256978 - SV-256978r902784_rule
RMF Control
CM-5
Severity
Medium
CCI
CCI-001749
Version
OL08-00-010019
Vuln IDs
  • V-256978
Rule IDs
  • SV-256978r902784_rule
Cryptographic verification of vendor software packages ensures that all software packages are obtained from a valid source and protects against spoofing that could lead to installation of malware on the system. Oracle cryptographically signs all software packages, which includes updates, with a GPG key to verify that they are valid.
Checks: C-60656r902782_chk

Confirm Oracle package-signing key is installed on the system and verify its fingerprint matches vendor value. Note: The GPG key is defined in key file "/etc/pki/rpm-gpg/RPM-GPG-KEY-oracle" by default. List Oracle GPG keys installed on the system: $ sudo rpm -q --queryformat "%{SUMMARY}\n" gpg-pubkey | grep -i "oracle" gpg(Oracle OSS group (Open Source Software group) &lt;build@oss.oracle.com&gt;) If Oracle GPG key is not installed, this is a finding. List key fingerprint of installed Oracle GPG key: $ sudo gpg -q --keyid-format short --with-fingerprint /etc/pki/rpm-gpg/RPM-GPG-KEY-oracle If key file "/etc/pki/rpm-gpg/RPM-GPG-KEY-oracle" is missing, this is a finding. Example output: pub rsa4096/AD986DA3 2019-04-09 [SC] [expires: 2039-04-04] Key fingerprint = 76FD 3DB1 3AB6 7410 B89D B10E 8256 2EA9 AD98 6DA3 uid Oracle OSS group (Open Source Software group) &lt;build@oss.oracle.com&gt; sub rsa4096/D95DC12B 2019-04-09 [E] [expires: 2039-04-04] Compare key fingerprint of installed Oracle GPG key with fingerprint listed for OL 8 on Oracle verification webpage at https://linux.oracle.com/security/gpg/#gpg. If key fingerprint does not match, this is a finding.

Fix: F-60598r902783_fix

Install Oracle package-signing key on the system and verify its fingerprint matches vendor value. Insert OL 8 installation disc or attach OL 8 installation image to the system. Mount the disc or image to make the contents accessible inside the system. Assuming the mounted location is "/media/cdrom", use the following command to copy Oracle GPG key file onto the system: $ sudo cp /media/cdrom/RPM-GPG-KEY-oracle /etc/pki/rpm-gpg/ Import Oracle GPG keys from key file into system keyring: $ sudo rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-oracle Using the steps listed in the Check Text, confirm the newly imported key shows as installed on the system and verify its fingerprint matches vendor value.

b
OL 8 must be configured to allow sending email notifications of unauthorized configuration changes to designated personnel.
CM-3 - Medium - CCI-001744 - V-256979 - SV-256979r902803_rule
RMF Control
CM-3
Severity
Medium
CCI
CCI-001744
Version
OL08-00-010358
Vuln IDs
  • V-256979
Rule IDs
  • SV-256979r902803_rule
Unauthorized changes to the baseline configuration could make the system vulnerable to various attacks or allow unauthorized access to the operating system. Changes to operating system configurations can have unintended side effects, some of which may be relevant to security. Detecting such changes and providing an automated response can help avoid unintended, negative consequences that could ultimately affect the security state of the operating system. The operating system's IMO/ISSO and SAs must be notified via email and/or monitoring system trap when there is an unauthorized modification of a configuration item.
Checks: C-60657r902801_chk

Verify that the operating system is configured to allow sending email notifications. Note: The "mailx" package provides the "mail" command that is used to send email messages. Verify that the "mailx" package is installed on the system: $ sudo yum list installed mailx mailx.x86_64 12.5-29.el8 @ol8_baseos_latest If "mailx" package is not installed, this is a finding.

Fix: F-60599r902802_fix

Install the "mailx" package on the system: $ sudo yum install mailx

b
OL 8 must terminate idle user sessions.
SC-10 - Medium - CCI-001133 - V-257259 - SV-257259r917919_rule
RMF Control
SC-10
Severity
Medium
CCI
CCI-001133
Version
OL08-00-020035
Vuln IDs
  • V-257259
Rule IDs
  • SV-257259r917919_rule
Terminating an idle session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been left unattended.
Checks: C-60943r917917_chk

Verify that OL 8 logs out sessions that are idle for 15 minutes with the following command: $ sudo grep -i ^StopIdleSessionSec /etc/systemd/logind.conf StopIdleSessionSec=900 If "StopIdleSessionSec" is not configured to 900 seconds, this is a finding.

Fix: F-60885r917918_fix

Configure OL 8 to log out idle sessions by editing the /etc/systemd/logind.conf file with the following line: StopIdleSessionSec=900 The "logind" service must be restarted for the changes to take effect. To restart the "logind" service, run the following command: $ sudo systemctl restart systemd-logind