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Oracle Linux 8 STIG SCAP Benchmark

  • Version/Release: V2R3
  • Published: 2024-12-03
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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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030180
Vuln IDs
V-248519
Rule IDs
SV-248519r1015024_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030181
Vuln IDs
V-248520
Rule IDs
SV-248520r1015025_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
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.
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
OL08-00-010000
Vuln IDs
V-248521
Rule IDs
SV-248521r991589_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.
Fix: F-51909r779128_fix

Upgrade to a supported version of the operating system.

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.
RMF Control
AC-17
Severity
High
CCI
CCI-000068
Version
OL08-00-010020
Vuln IDs
V-248524
Rule IDs
SV-248524r958408_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
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
OL 8 must display a banner before granting local or remote access to the system via a graphical user logon.
RMF Control
AC-8
Severity
Medium
CCI
CCI-000048
Version
OL08-00-010049
Vuln IDs
V-248527
Rule IDs
SV-248527r958390_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
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
All OL 8 remote access methods must be monitored.
RMF Control
AC-17
Severity
Medium
CCI
CCI-000067
Version
OL08-00-010070
Vuln IDs
V-248530
Rule IDs
SV-248530r958406_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, nonorganization-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).
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 must encrypt all stored passwords with a FIPS 140-2 approved cryptographic hashing algorithm.
RMF Control
Severity
Medium
CCI
CCI-004062
Version
OL08-00-010110
Vuln IDs
V-248533
Rule IDs
SV-248533r1015028_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.
Fix: F-51921r986325_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.
RMF Control
Severity
Medium
CCI
CCI-004062
Version
OL08-00-010120
Vuln IDs
V-248534
Rule IDs
SV-248534r1015029_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.
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.
RMF Control
Severity
Medium
CCI
CCI-004062
Version
OL08-00-010130
Vuln IDs
V-248535
Rule IDs
SV-248535r1044786_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.
Fix: F-51923r1044785_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 "100000": SHA_CRYPT_MIN_ROUNDS 100000

c
OL 8 operating systems booted with United Extensible Firmware Interface (UEFI) must require authentication upon booting into single-user mode and maintenance.
RMF Control
AC-3
Severity
High
CCI
CCI-000213
Version
OL08-00-010140
Vuln IDs
V-248537
Rule IDs
SV-248537r958472_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.
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:

c
OL 8 operating systems booted with a BIOS must require authentication upon booting into single-user and maintenance modes.
RMF Control
AC-3
Severity
High
CCI
CCI-000213
Version
OL08-00-010150
Vuln IDs
V-248540
Rule IDs
SV-248540r958472_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.
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.
RMF Control
AC-3
Severity
Medium
CCI
CCI-000213
Version
OL08-00-010151
Vuln IDs
V-248541
Rule IDs
SV-248541r958472_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.
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.
RMF Control
AC-3
Severity
Medium
CCI
CCI-000213
Version
OL08-00-010152
Vuln IDs
V-248542
Rule IDs
SV-248542r958472_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.
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.
RMF Control
IA-7
Severity
Medium
CCI
CCI-000803
Version
OL08-00-010159
Vuln IDs
V-248543
Rule IDs
SV-248543r971535_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.
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.
RMF Control
IA-7
Severity
Medium
CCI
CCI-000803
Version
OL08-00-010160
Vuln IDs
V-248544
Rule IDs
SV-248544r971535_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.
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.
RMF Control
IA-7
Severity
Medium
CCI
CCI-000803
Version
OL08-00-010161
Vuln IDs
V-248545
Rule IDs
SV-248545r971535_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.
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.
RMF Control
IA-7
Severity
Medium
CCI
CCI-000803
Version
OL08-00-010162
Vuln IDs
V-248546
Rule IDs
SV-248546r971535_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.
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.
RMF Control
IA-7
Severity
Medium
CCI
CCI-000803
Version
OL08-00-010163
Vuln IDs
V-248547
Rule IDs
SV-248547r971535_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.
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.
RMF Control
SC-3
Severity
Medium
CCI
CCI-001084
Version
OL08-00-010170
Vuln IDs
V-248548
Rule IDs
SV-248548r958518_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.
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.
RMF Control
SC-3
Severity
Low
CCI
CCI-001084
Version
OL08-00-010171
Vuln IDs
V-248549
Rule IDs
SV-248549r958518_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.
Fix: F-51937r779212_fix

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

b
OL 8 must be configured so that all network connections associated with SSH traffic terminate after becoming unresponsive.
RMF Control
SC-10
Severity
Medium
CCI
CCI-001133
Version
OL08-00-010200
Vuln IDs
V-248552
Rule IDs
SV-248552r986329_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
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.
RMF Control
SC-10
Severity
Medium
CCI
CCI-001133
Version
OL08-00-010201
Vuln IDs
V-248553
Rule IDs
SV-248553r986330_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, deallocating associated TCP/IP address/port pairs at the operating system level and deallocating 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
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.
RMF Control
SI-11
Severity
Medium
CCI
CCI-001314
Version
OL08-00-010210
Vuln IDs
V-248554
Rule IDs
SV-248554r958566_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.
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.
RMF Control
SI-11
Severity
Medium
CCI
CCI-001314
Version
OL08-00-010220
Vuln IDs
V-248555
Rule IDs
SV-248555r958566_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.
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.
RMF Control
SI-11
Severity
Medium
CCI
CCI-001314
Version
OL08-00-010230
Vuln IDs
V-248556
Rule IDs
SV-248556r958566_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.
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.
RMF Control
SI-11
Severity
Medium
CCI
CCI-001314
Version
OL08-00-010240
Vuln IDs
V-248557
Rule IDs
SV-248557r958566_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.
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.
RMF Control
SI-11
Severity
Medium
CCI
CCI-001314
Version
OL08-00-010250
Vuln IDs
V-248558
Rule IDs
SV-248558r958566_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.
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.
RMF Control
SI-11
Severity
Medium
CCI
CCI-001314
Version
OL08-00-010260
Vuln IDs
V-248559
Rule IDs
SV-248559r958566_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.
Fix: F-51947r779242_fix

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

a
The OL 8 SSH server must be configured to use strong entropy.
RMF Control
CM-6
Severity
Low
CCI
CCI-000366
Version
OL08-00-010292
Vuln IDs
V-248563
Rule IDs
SV-248563r991593_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.
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 TLS encryption in the OpenSSL package.
RMF Control
AC-17
Severity
Medium
CCI
CCI-001453
Version
OL08-00-010294
Vuln IDs
V-248565
Rule IDs
SV-248565r991554_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
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
OL 8 system commands must have mode 755 or less permissive.
RMF Control
CM-5
Severity
Medium
CCI
CCI-001499
Version
OL08-00-010300
Vuln IDs
V-248567
Rule IDs
SV-248567r991560_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.
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.
RMF Control
CM-5
Severity
Medium
CCI
CCI-001499
Version
OL08-00-010310
Vuln IDs
V-248568
Rule IDs
SV-248568r991560_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.
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.
RMF Control
CM-5
Severity
Medium
CCI
CCI-001499
Version
OL08-00-010320
Vuln IDs
V-248569
Rule IDs
SV-248569r991560_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.
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.
RMF Control
CM-5
Severity
Medium
CCI
CCI-001499
Version
OL08-00-010330
Vuln IDs
V-248570
Rule IDs
SV-248570r991560_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.
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.
RMF Control
CM-5
Severity
Medium
CCI
CCI-001499
Version
OL08-00-010340
Vuln IDs
V-248571
Rule IDs
SV-248571r991560_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.
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.
RMF Control
CM-5
Severity
Medium
CCI
CCI-001499
Version
OL08-00-010350
Vuln IDs
V-248572
Rule IDs
SV-248572r991560_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.
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]

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.
RMF Control
Severity
High
CCI
CCI-003992
Version
OL08-00-010370
Vuln IDs
V-248574
Rule IDs
SV-248574r1015031_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).
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.
RMF Control
Severity
High
CCI
CCI-003992
Version
OL08-00-010371
Vuln IDs
V-248575
Rule IDs
SV-248575r1015032_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).
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 enable kernel parameters to enforce Discretionary Access Control (DAC) on symlinks.
RMF Control
AC-3
Severity
Medium
CCI
CCI-002165
Version
OL08-00-010373
Vuln IDs
V-248577
Rule IDs
SV-248577r958702_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
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.
RMF Control
AC-3
Severity
Medium
CCI
CCI-002165
Version
OL08-00-010374
Vuln IDs
V-248578
Rule IDs
SV-248578r958702_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
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.
RMF Control
SC-4
Severity
Low
CCI
CCI-001090
Version
OL08-00-010375
Vuln IDs
V-248579
Rule IDs
SV-248579r958524_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
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.
RMF Control
SC-4
Severity
Low
CCI
CCI-001090
Version
OL08-00-010376
Vuln IDs
V-248580
Rule IDs
SV-248580r958524_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
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.
RMF Control
Severity
Medium
CCI
CCI-004895
Version
OL08-00-010380
Vuln IDs
V-248581
Rule IDs
SV-248581r1050789_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
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.
RMF Control
Severity
Medium
CCI
CCI-004895
Version
OL08-00-010381
Vuln IDs
V-248582
Rule IDs
SV-248582r1050789_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
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010382
Vuln IDs
V-248583
Rule IDs
SV-248583r991589_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.
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".
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010383
Vuln IDs
V-248584
Rule IDs
SV-248584r991589_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.
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 reauthentication when using the "sudo" command.
RMF Control
Severity
Medium
CCI
CCI-004895
Version
OL08-00-010384
Vuln IDs
V-248585
Rule IDs
SV-248585r1050789_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 organization requires the user to reauthenticate 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 reauthenticate 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
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.
RMF Control
Severity
Low
CCI
CCI-004046
Version
OL08-00-010390
Vuln IDs
V-248586
Rule IDs
SV-248586r1015037_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, nonorganization-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).
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 clear the page allocator to prevent use-after-free attacks.
RMF Control
SC-3
Severity
Medium
CCI
CCI-001084
Version
OL08-00-010421
Vuln IDs
V-248590
Rule IDs
SV-248590r958518_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.
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.
RMF Control
SC-3
Severity
Medium
CCI
CCI-001084
Version
OL08-00-010422
Vuln IDs
V-248591
Rule IDs
SV-248591r958518_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.
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.
RMF Control
SC-3
Severity
Medium
CCI
CCI-001084
Version
OL08-00-010423
Vuln IDs
V-248592
Rule IDs
SV-248592r958518_rule
Some adversaries launch attacks with the intent of executing code in nonexecutable 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.
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 implement address space layout randomization (ASLR) to protect its memory from unauthorized code execution.
RMF Control
SI-16
Severity
Medium
CCI
CCI-002824
Version
OL08-00-010430
Vuln IDs
V-248594
Rule IDs
SV-248594r958928_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
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.
RMF Control
SI-2
Severity
Low
CCI
CCI-002617
Version
OL08-00-010440
Vuln IDs
V-248595
Rule IDs
SV-248595r958936_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.
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.
RMF Control
SI-6
Severity
Medium
CCI
CCI-002696
Version
OL08-00-010450
Vuln IDs
V-248596
Rule IDs
SV-248596r958944_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.
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.
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
OL08-00-010460
Vuln IDs
V-248597
Rule IDs
SV-248597r991589_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.
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.
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
OL08-00-010470
Vuln IDs
V-248598
Rule IDs
SV-248598r991589_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.
Fix: F-51986r779359_fix

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

a
OL 8 must have the packages required to use the hardware random number generator entropy gatherer service.
RMF Control
CM-6
Severity
Low
CCI
CCI-000366
Version
OL08-00-010472
Vuln IDs
V-248600
Rule IDs
SV-248600r991589_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).
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010480
Vuln IDs
V-248601
Rule IDs
SV-248601r991589_rule
If a public host key file is modified by an unauthorized user, the SSH service may be compromised.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010490
Vuln IDs
V-248602
Rule IDs
SV-248602r991589_rule
If an unauthorized user obtains the private SSH host key file, the host could be impersonated.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010500
Vuln IDs
V-248603
Rule IDs
SV-248603r991589_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010520
Vuln IDs
V-248605
Rule IDs
SV-248605r991589_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010521
Vuln IDs
V-248606
Rule IDs
SV-248606r991589_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010522
Vuln IDs
V-248607
Rule IDs
SV-248607r991589_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.
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".
RMF Control
CM-6
Severity
Low
CCI
CCI-000366
Version
OL08-00-010540
Vuln IDs
V-248608
Rule IDs
SV-248608r991589_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.
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".
RMF Control
CM-6
Severity
Low
CCI
CCI-000366
Version
OL08-00-010541
Vuln IDs
V-248609
Rule IDs
SV-248609r991589_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.
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.
RMF Control
CM-6
Severity
Low
CCI
CCI-000366
Version
OL08-00-010542
Vuln IDs
V-248610
Rule IDs
SV-248610r991589_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.
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".
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010543
Vuln IDs
V-248611
Rule IDs
SV-248611r991589_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010544
Vuln IDs
V-248612
Rule IDs
SV-248612r991589_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.
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.
RMF Control
Severity
Medium
CCI
CCI-004045
Version
OL08-00-010550
Vuln IDs
V-248613
Rule IDs
SV-248613r1015039_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010561
Vuln IDs
V-248615
Rule IDs
SV-248615r991589_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010570
Vuln IDs
V-248616
Rule IDs
SV-248616r991589_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010571
Vuln IDs
V-248617
Rule IDs
SV-248617r991589_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010572
Vuln IDs
V-248618
Rule IDs
SV-248618r991589_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010580
Vuln IDs
V-248619
Rule IDs
SV-248619r991589_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.
Fix: F-52007r779422_fix

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

b
OL 8 file systems must not execute binary files that are imported via Network File System (NFS).
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010630
Vuln IDs
V-248624
Rule IDs
SV-248624r991589_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010640
Vuln IDs
V-248625
Rule IDs
SV-248625r991589_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.
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).
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010650
Vuln IDs
V-248626
Rule IDs
SV-248626r991589_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.
Fix: F-52014r779443_fix

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

b
OL 8 must disable the "kernel.core_pattern".
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010671
Vuln IDs
V-248629
Rule IDs
SV-248629r991589_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
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010672
Vuln IDs
V-248630
Rule IDs
SV-248630r991589_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010673
Vuln IDs
V-248631
Rule IDs
SV-248631r991589_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010674
Vuln IDs
V-248632
Rule IDs
SV-248632r991589_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010675
Vuln IDs
V-248633
Rule IDs
SV-248633r991589_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010680
Vuln IDs
V-248634
Rule IDs
SV-248634r991589_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.
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
All OL 8 local interactive users must have a home directory assigned in the "/etc/passwd" file.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010720
Vuln IDs
V-248638
Rule IDs
SV-248638r991589_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010730
Vuln IDs
V-248639
Rule IDs
SV-248639r991589_rule
Excessive permissions on local interactive user home directories may allow unauthorized access to user files by other users.
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 accounts must be assigned a home directory upon creation.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010760
Vuln IDs
V-248644
Rule IDs
SV-248644r991589_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010770
Vuln IDs
V-248645
Rule IDs
SV-248645r991589_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.
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
A separate OL 8 filesystem must be used for user home directories (such as "/home" or an equivalent).
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-010800
Vuln IDs
V-248648
Rule IDs
SV-248648r991589_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.
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.
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
OL08-00-010820
Vuln IDs
V-248649
Rule IDs
SV-248649r991591_rule
Failure to restrict system access to authenticated users negatively impacts operating system security.
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.
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
OL08-00-010830
Vuln IDs
V-248650
Rule IDs
SV-248650r991591_rule
SSH environment options potentially allow users to bypass access restriction in some configurations.
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 systems below version 8.2 must automatically lock an account when three unsuccessful logon attempts occur.
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020010
Vuln IDs
V-248652
Rule IDs
SV-248652r958388_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
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.
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020011
Vuln IDs
V-248653
Rule IDs
SV-248653r958388_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
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.
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020012
Vuln IDs
V-248654
Rule IDs
SV-248654r958388_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
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.
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020013
Vuln IDs
V-248655
Rule IDs
SV-248655r958388_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
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.
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020014
Vuln IDs
V-248656
Rule IDs
SV-248656r958388_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
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.
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020015
Vuln IDs
V-248657
Rule IDs
SV-248657r958388_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
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 prevent system messages from being presented when three unsuccessful logon attempts occur.
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020018
Vuln IDs
V-248660
Rule IDs
SV-248660r958388_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
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.
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020019
Vuln IDs
V-248661
Rule IDs
SV-248661r958388_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
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.
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020020
Vuln IDs
V-248662
Rule IDs
SV-248662r958388_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
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.
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020021
Vuln IDs
V-248663
Rule IDs
SV-248663r958388_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
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.
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020022
Vuln IDs
V-248664
Rule IDs
SV-248664r958388_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
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.
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
OL08-00-020023
Vuln IDs
V-248665
Rule IDs
SV-248665r958388_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
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.
RMF Control
AC-10
Severity
Low
CCI
CCI-000054
Version
OL08-00-020024
Vuln IDs
V-248666
Rule IDs
SV-248666r958398_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.
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 enable a user session lock until that user reestablishes access using established identification and authentication procedures for graphical user sessions.
RMF Control
AC-11
Severity
Medium
CCI
CCI-000056
Version
OL08-00-020030
Vuln IDs
V-248671
Rule IDs
SV-248671r1015040_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
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 disable the user list at logon for graphical user interfaces.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-020032
Vuln IDs
V-248673
Rule IDs
SV-248673r991589_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.
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.
RMF Control
AC-11
Severity
Medium
CCI
CCI-000056
Version
OL08-00-020039
Vuln IDs
V-248674
Rule IDs
SV-248674r1015041_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
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.
RMF Control
AC-11
Severity
Medium
CCI
CCI-000056
Version
OL08-00-020040
Vuln IDs
V-248675
Rule IDs
SV-248675r1015042_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
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

a
OL 8 must prevent users from disabling session control mechanisms.
RMF Control
AC-11
Severity
Low
CCI
CCI-000056
Version
OL08-00-020042
Vuln IDs
V-248677
Rule IDs
SV-248677r1015044_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
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 be able to initiate directly a session lock for all connection types using smartcard when the smartcard is removed.
RMF Control
AC-11
Severity
Medium
CCI
CCI-000056
Version
OL08-00-020050
Vuln IDs
V-248679
Rule IDs
SV-248679r1015046_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
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 prevent a user from overriding the session lock-delay setting for the graphical user interface.
RMF Control
AC-11
Severity
Medium
CCI
CCI-000057
Version
OL08-00-020080
Vuln IDs
V-248682
Rule IDs
SV-248682r958402_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
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 lock-enabled setting for the graphical user interface.
RMF Control
AC-11
Severity
Medium
CCI
CCI-000057
Version
OL08-00-020082
Vuln IDs
V-248684
Rule IDs
SV-248684r958402_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
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 ensure the password complexity module is enabled in the password-auth file.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-020100
Vuln IDs
V-248686
Rule IDs
SV-248686r982195_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
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.
RMF Control
Severity
Low
CCI
CCI-004066
Version
OL08-00-020110
Vuln IDs
V-248687
Rule IDs
SV-248687r1015047_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
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.
RMF Control
Severity
Low
CCI
CCI-004066
Version
OL08-00-020120
Vuln IDs
V-248688
Rule IDs
SV-248688r1015048_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".
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.
RMF Control
Severity
Low
CCI
CCI-004066
Version
OL08-00-020130
Vuln IDs
V-248689
Rule IDs
SV-248689r1015049_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".
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.
RMF Control
Severity
Medium
CCI
CCI-004066
Version
OL08-00-020140
Vuln IDs
V-248690
Rule IDs
SV-248690r1015050_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.
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.
RMF Control
Severity
Medium
CCI
CCI-004066
Version
OL08-00-020150
Vuln IDs
V-248691
Rule IDs
SV-248691r1015051_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.
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.
RMF Control
Severity
Medium
CCI
CCI-004066
Version
OL08-00-020160
Vuln IDs
V-248692
Rule IDs
SV-248692r1015052_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, uppercase, lowercase, others).
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 eight characters when passwords are changed.
RMF Control
Severity
Low
CCI
CCI-004066
Version
OL08-00-020170
Vuln IDs
V-248693
Rule IDs
SV-248693r1015053_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.
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/one day minimum password lifetime restriction in "/etc/shadow".
RMF Control
Severity
Medium
CCI
CCI-004066
Version
OL08-00-020180
Vuln IDs
V-248694
Rule IDs
SV-248694r1015054_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.
Fix: F-52082r986358_fix

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

b
OL 8 passwords for new users or password changes must have a 24 hours/one day minimum password lifetime restriction in "/etc/login.defs".
RMF Control
Severity
Medium
CCI
CCI-004066
Version
OL08-00-020190
Vuln IDs
V-248695
Rule IDs
SV-248695r1015055_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.
Fix: F-52083r986361_fix

Configure OL 8 to enforce 24 hours/one 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.
RMF Control
Severity
Medium
CCI
CCI-004066
Version
OL08-00-020200
Vuln IDs
V-248696
Rule IDs
SV-248696r1038967_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.
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.
RMF Control
Severity
Medium
CCI
CCI-004066
Version
OL08-00-020210
Vuln IDs
V-248697
Rule IDs
SV-248697r1038967_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.
Fix: F-52085r779656_fix

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

b
OL 8 passwords must have a minimum of 15 characters.
RMF Control
Severity
Medium
CCI
CCI-004066
Version
OL08-00-020230
Vuln IDs
V-248699
Rule IDs
SV-248699r1015058_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.
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.
RMF Control
Severity
Medium
CCI
CCI-004066
Version
OL08-00-020231
Vuln IDs
V-248700
Rule IDs
SV-248700r1015059_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.
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000135
Version
OL08-00-020240
Vuln IDs
V-248701
Rule IDs
SV-248701r958422_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
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
The OL 8 lastlog command must have a mode of "0750" or less permissive.
RMF Control
SI-11
Severity
Medium
CCI
CCI-001314
Version
OL08-00-020262
Vuln IDs
V-248705
Rule IDs
SV-248705r958566_rule
Unauthorized disclosure of the contents of the /var/log/lastlog file can reveal system data to attackers, thus compromising its confidentiality.
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.
RMF Control
SI-11
Severity
Medium
CCI
CCI-001314
Version
OL08-00-020263
Vuln IDs
V-248706
Rule IDs
SV-248706r958566_rule
Unauthorized disclosure of the contents of the /var/log/lastlog file can reveal system data to attackers, thus compromising its confidentiality.
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.
RMF Control
SI-11
Severity
Medium
CCI
CCI-001314
Version
OL08-00-020264
Vuln IDs
V-248707
Rule IDs
SV-248707r958566_rule
Unauthorized disclosure of the contents of the /var/log/lastlog file can reveal system data to attackers, thus compromising its confidentiality.
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

a
All OL 8 passwords must contain at least one special character.
RMF Control
Severity
Low
CCI
CCI-004066
Version
OL08-00-020280
Vuln IDs
V-248709
Rule IDs
SV-248709r1015063_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".
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.
RMF Control
IA-5
Severity
Medium
CCI
CCI-002007
Version
OL08-00-020290
Vuln IDs
V-248710
Rule IDs
SV-248710r958828_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-020300
Vuln IDs
V-248711
Rule IDs
SV-248711r991587_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-020310
Vuln IDs
V-248712
Rule IDs
SV-248712r991588_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.
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

c
OL 8 must not allow accounts configured with blank or null passwords.
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
OL08-00-020330
Vuln IDs
V-248714
Rule IDs
SV-248714r991589_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.
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.
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
OL08-00-020331
Vuln IDs
V-248715
Rule IDs
SV-248715r991589_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.
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.
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
OL08-00-020332
Vuln IDs
V-248716
Rule IDs
SV-248716r991589_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.
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.
RMF Control
AC-9
Severity
Low
CCI
CCI-000052
Version
OL08-00-020340
Vuln IDs
V-248717
Rule IDs
SV-248717r991589_rule
Providing users with feedback on when account accesses last occurred facilitates user recognition and reporting of unauthorized account use.
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.
RMF Control
AC-9
Severity
Medium
CCI
CCI-000052
Version
OL08-00-020350
Vuln IDs
V-248718
Rule IDs
SV-248718r991589_rule
Providing users with feedback on when account accesses via SSH last occurred facilitates user recognition and reporting of unauthorized account use.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-020351
Vuln IDs
V-248719
Rule IDs
SV-248719r991590_rule
Setting the most restrictive default permissions ensures that when new accounts are created, they do not have unnecessary access.
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
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.
RMF Control
AC-6
Severity
Medium
CCI
CCI-002233
Version
OL08-00-030000
Vuln IDs
V-248722
Rule IDs
SV-248722r958730_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
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
The OL 8 System Administrator (SA) and Information System Security Officer (ISSO) (at a minimum) must be alerted of an audit processing failure event.
RMF Control
AU-5
Severity
Medium
CCI
CCI-000139
Version
OL08-00-030020
Vuln IDs
V-248724
Rule IDs
SV-248724r958424_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.
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.
RMF Control
AU-5
Severity
Medium
CCI
CCI-000139
Version
OL08-00-030030
Vuln IDs
V-248725
Rule IDs
SV-248725r958424_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.
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.
RMF Control
AU-5
Severity
Medium
CCI
CCI-000140
Version
OL08-00-030040
Vuln IDs
V-248726
Rule IDs
SV-248726r1038966_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.
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.
RMF Control
AU-5
Severity
Medium
CCI
CCI-000140
Version
OL08-00-030060
Vuln IDs
V-248728
Rule IDs
SV-248728r1038966_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-030061
Vuln IDs
V-248729
Rule IDs
SV-248729r991589_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.
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.
RMF Control
AU-4
Severity
Medium
CCI
CCI-001851
Version
OL08-00-030062
Vuln IDs
V-248730
Rule IDs
SV-248730r958754_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-030063
Vuln IDs
V-248731
Rule IDs
SV-248731r991589_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.
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.
RMF Control
AU-9
Severity
Medium
CCI
CCI-000162
Version
OL08-00-030070
Vuln IDs
V-248732
Rule IDs
SV-248732r958434_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
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.
RMF Control
AU-9
Severity
Medium
CCI
CCI-000162
Version
OL08-00-030080
Vuln IDs
V-248733
Rule IDs
SV-248733r958434_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
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.
RMF Control
AU-9
Severity
Medium
CCI
CCI-000162
Version
OL08-00-030090
Vuln IDs
V-248734
Rule IDs
SV-248734r958434_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
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.
RMF Control
AU-9
Severity
Medium
CCI
CCI-000162
Version
OL08-00-030100
Vuln IDs
V-248735
Rule IDs
SV-248735r958434_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
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.
RMF Control
AU-9
Severity
Medium
CCI
CCI-000162
Version
OL08-00-030110
Vuln IDs
V-248736
Rule IDs
SV-248736r958434_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
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.
RMF Control
AU-9
Severity
Medium
CCI
CCI-000162
Version
OL08-00-030120
Vuln IDs
V-248737
Rule IDs
SV-248737r958434_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
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.
RMF Control
AU-9
Severity
Medium
CCI
CCI-000162
Version
OL08-00-030121
Vuln IDs
V-248738
Rule IDs
SV-248738r958434_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
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.
RMF Control
AU-9
Severity
Medium
CCI
CCI-000162
Version
OL08-00-030122
Vuln IDs
V-248739
Rule IDs
SV-248739r958434_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
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".
RMF Control
AC-2
Severity
Medium
CCI
CCI-000018
Version
OL08-00-030130
Vuln IDs
V-248740
Rule IDs
SV-248740r1015064_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
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".
RMF Control
AC-2
Severity
Medium
CCI
CCI-000018
Version
OL08-00-030140
Vuln IDs
V-248741
Rule IDs
SV-248741r1015065_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
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".
RMF Control
AC-2
Severity
Medium
CCI
CCI-000018
Version
OL08-00-030150
Vuln IDs
V-248742
Rule IDs
SV-248742r1015066_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
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".
RMF Control
AC-2
Severity
Medium
CCI
CCI-000018
Version
OL08-00-030160
Vuln IDs
V-248743
Rule IDs
SV-248743r1015067_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
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".
RMF Control
AC-2
Severity
Medium
CCI
CCI-000018
Version
OL08-00-030170
Vuln IDs
V-248744
Rule IDs
SV-248744r1015068_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
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".
RMF Control
AC-2
Severity
Medium
CCI
CCI-000018
Version
OL08-00-030171
Vuln IDs
V-248745
Rule IDs
SV-248745r1015069_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
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/".
RMF Control
AC-2
Severity
Medium
CCI
CCI-000018
Version
OL08-00-030172
Vuln IDs
V-248746
Rule IDs
SV-248746r1015070_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030190
Vuln IDs
V-248747
Rule IDs
SV-248747r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030200
Vuln IDs
V-248748
Rule IDs
SV-248748r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030250
Vuln IDs
V-248753
Rule IDs
SV-248753r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030260
Vuln IDs
V-248754
Rule IDs
SV-248754r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030280
Vuln IDs
V-248756
Rule IDs
SV-248756r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030290
Vuln IDs
V-248757
Rule IDs
SV-248757r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030300
Vuln IDs
V-248758
Rule IDs
SV-248758r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030301
Vuln IDs
V-248759
Rule IDs
SV-248759r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030302
Vuln IDs
V-248760
Rule IDs
SV-248760r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030310
Vuln IDs
V-248761
Rule IDs
SV-248761r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030311
Vuln IDs
V-248762
Rule IDs
SV-248762r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030312
Vuln IDs
V-248763
Rule IDs
SV-248763r958412_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
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.
RMF Control
AU-12
Severity
Medium
CCI
CCI-000169
Version
OL08-00-030313
Vuln IDs
V-248764
Rule IDs
SV-248764r958442_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.
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.
RMF Control
AU-12
Severity
Medium
CCI
CCI-000169
Version
OL08-00-030314
Vuln IDs
V-248765
Rule IDs
SV-248765r958442_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.
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.
RMF Control
AU-12
Severity
Medium
CCI
CCI-000169
Version
OL08-00-030315
Vuln IDs
V-248766
Rule IDs
SV-248766r958442_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.
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030316
Vuln IDs
V-248767
Rule IDs
SV-248767r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030317
Vuln IDs
V-248768
Rule IDs
SV-248768r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030320
Vuln IDs
V-248769
Rule IDs
SV-248769r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030330
Vuln IDs
V-248770
Rule IDs
SV-248770r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030340
Vuln IDs
V-248771
Rule IDs
SV-248771r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030350
Vuln IDs
V-248772
Rule IDs
SV-248772r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030360
Vuln IDs
V-248773
Rule IDs
SV-248773r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030361
Vuln IDs
V-248774
Rule IDs
SV-248774r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030370
Vuln IDs
V-248779
Rule IDs
SV-248779r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030390
Vuln IDs
V-248781
Rule IDs
SV-248781r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030400
Vuln IDs
V-248782
Rule IDs
SV-248782r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030410
Vuln IDs
V-248783
Rule IDs
SV-248783r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030420
Vuln IDs
V-248784
Rule IDs
SV-248784r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030480
Vuln IDs
V-248790
Rule IDs
SV-248790r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030490
Vuln IDs
V-248791
Rule IDs
SV-248791r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030550
Vuln IDs
V-248797
Rule IDs
SV-248797r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030560
Vuln IDs
V-248798
Rule IDs
SV-248798r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030570
Vuln IDs
V-248799
Rule IDs
SV-248799r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030580
Vuln IDs
V-248800
Rule IDs
SV-248800r958412_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
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 "lastlog" file.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030600
Vuln IDs
V-248802
Rule IDs
SV-248802r958412_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
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.
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
OL08-00-030601
Vuln IDs
V-248803
Rule IDs
SV-248803r958412_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
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.
RMF Control
AU-3
Severity
Low
CCI
CCI-000130
Version
OL08-00-030602
Vuln IDs
V-248804
Rule IDs
SV-248804r958412_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
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 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.
RMF Control
AU-12
Severity
Medium
CCI
CCI-000171
Version
OL08-00-030610
Vuln IDs
V-248806
Rule IDs
SV-248806r958444_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.
Fix: F-52194r951580_fix

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

b
OL 8 audit tools must have a mode of "0755" or less permissive.
RMF Control
AU-9
Severity
Medium
CCI
CCI-001493
Version
OL08-00-030620
Vuln IDs
V-248807
Rule IDs
SV-248807r991557_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.
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.
RMF Control
AU-9
Severity
Medium
CCI
CCI-001493
Version
OL08-00-030630
Vuln IDs
V-248808
Rule IDs
SV-248808r991557_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
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.
RMF Control
AU-9
Severity
Medium
CCI
CCI-001493
Version
OL08-00-030640
Vuln IDs
V-248809
Rule IDs
SV-248809r991557_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
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 have the packages required for offloading audit logs installed.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-030670
Vuln IDs
V-248812
Rule IDs
SV-248812r991589_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-030680
Vuln IDs
V-248813
Rule IDs
SV-248813r991589_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.
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
OL 8 must take appropriate action when the internal event queue is full.
RMF Control
AU-4
Severity
Medium
CCI
CCI-001851
Version
OL08-00-030700
Vuln IDs
V-248815
Rule IDs
SV-248815r958754_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
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 authenticate the remote logging server for offloading audit logs.
RMF Control
AU-4
Severity
Medium
CCI
CCI-001851
Version
OL08-00-030720
Vuln IDs
V-248817
Rule IDs
SV-248817r958754_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
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.
RMF Control
AU-5
Severity
Medium
CCI
CCI-001855
Version
OL08-00-030730
Vuln IDs
V-248818
Rule IDs
SV-248818r971542_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.
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.
RMF Control
AU-5
Severity
Medium
CCI
CCI-001855
Version
OL08-00-030731
Vuln IDs
V-248819
Rule IDs
SV-248819r971542_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.
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.

a
OL 8 must disable the chrony daemon from acting as a server.
RMF Control
CM-7
Severity
Low
CCI
CCI-000381
Version
OL08-00-030741
Vuln IDs
V-248821
Rule IDs
SV-248821r958478_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.
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.
RMF Control
CM-7
Severity
Low
CCI
CCI-000381
Version
OL08-00-030742
Vuln IDs
V-248822
Rule IDs
SV-248822r958478_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.
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.
RMF Control
CM-7
Severity
High
CCI
CCI-000381
Version
OL08-00-040000
Vuln IDs
V-248823
Rule IDs
SV-248823r958478_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.
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.
RMF Control
CM-7
Severity
Medium
CCI
CCI-000381
Version
OL08-00-040001
Vuln IDs
V-248824
Rule IDs
SV-248824r958478_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.
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.
RMF Control
CM-7
Severity
Medium
CCI
CCI-000381
Version
OL08-00-040002
Vuln IDs
V-248825
Rule IDs
SV-248825r958478_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.
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.
RMF Control
CM-7
Severity
Low
CCI
CCI-000381
Version
OL08-00-040004
Vuln IDs
V-248826
Rule IDs
SV-248826r958478_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).
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.
RMF Control
CM-7
Severity
High
CCI
CCI-000381
Version
OL08-00-040010
Vuln IDs
V-248827
Rule IDs
SV-248827r958478_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.
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 not have the asynchronous transfer mode (ATM) kernel module installed if not required for operational support.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040021
Vuln IDs
V-248829
Rule IDs
SV-248829r991589_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040022
Vuln IDs
V-248830
Rule IDs
SV-248830r991589_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040023
Vuln IDs
V-248831
Rule IDs
SV-248831r991589_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.
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.
RMF Control
CM-7
Severity
Low
CCI
CCI-000381
Version
OL08-00-040024
Vuln IDs
V-248832
Rule IDs
SV-248832r958478_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.
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.
RMF Control
CM-7
Severity
Low
CCI
CCI-000381
Version
OL08-00-040025
Vuln IDs
V-248833
Rule IDs
SV-248833r958478_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.
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.
RMF Control
CM-7
Severity
Low
CCI
CCI-000381
Version
OL08-00-040026
Vuln IDs
V-248834
Rule IDs
SV-248834r958478_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.
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
The OL 8 file system automounter must be disabled unless required.
RMF Control
IA-3
Severity
Medium
CCI
CCI-000778
Version
OL08-00-040070
Vuln IDs
V-248836
Rule IDs
SV-248836r958498_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.
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.
RMF Control
IA-3
Severity
Medium
CCI
CCI-000778
Version
OL08-00-040080
Vuln IDs
V-248837
Rule IDs
SV-248837r986386_rule
USB mass storage permits easy introduction of unknown devices, thereby facilitating malicious activity.
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
A firewall must be installed on OL 8.
RMF Control
AC-17
Severity
Medium
CCI
CCI-002314
Version
OL08-00-040100
Vuln IDs
V-248840
Rule IDs
SV-248840r958672_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).
Fix: F-52228r780085_fix

Install "firewalld" with the following commands: $ sudo yum install firewalld.noarch

b
A firewall must be active on OL 8.
RMF Control
AC-17
Severity
Medium
CCI
CCI-002314
Version
OL08-00-040101
Vuln IDs
V-248841
Rule IDs
SV-248841r958672_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).
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 Bluetooth must be disabled.
RMF Control
AC-18
Severity
Medium
CCI
CCI-001443
Version
OL08-00-040111
Vuln IDs
V-248843
Rule IDs
SV-248843r991569_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.
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.
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040120
Vuln IDs
V-248844
Rule IDs
SV-248844r958804_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.
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.
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040121
Vuln IDs
V-248845
Rule IDs
SV-248845r958804_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.
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.
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040122
Vuln IDs
V-248846
Rule IDs
SV-248846r958804_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.
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.
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040123
Vuln IDs
V-248847
Rule IDs
SV-248847r958804_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.
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.
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040124
Vuln IDs
V-248848
Rule IDs
SV-248848r958804_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.
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.
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040125
Vuln IDs
V-248849
Rule IDs
SV-248849r958804_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.
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.
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040126
Vuln IDs
V-248850
Rule IDs
SV-248850r958804_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.
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.
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040127
Vuln IDs
V-248851
Rule IDs
SV-248851r958804_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.
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.
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040128
Vuln IDs
V-248852
Rule IDs
SV-248852r958804_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.
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.
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040129
Vuln IDs
V-248853
Rule IDs
SV-248853r958804_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.
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.
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040130
Vuln IDs
V-248854
Rule IDs
SV-248854r958804_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.
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.
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040131
Vuln IDs
V-248855
Rule IDs
SV-248855r958804_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.
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.
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040132
Vuln IDs
V-248856
Rule IDs
SV-248856r958804_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.
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.
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040133
Vuln IDs
V-248857
Rule IDs
SV-248857r958804_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.
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.
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040134
Vuln IDs
V-248858
Rule IDs
SV-248858r958804_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.
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.
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040135
Vuln IDs
V-248859
Rule IDs
SV-248859r958804_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
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.
RMF Control
CM-7
Severity
Medium
CCI
CCI-001764
Version
OL08-00-040136
Vuln IDs
V-248860
Rule IDs
SV-248860r958804_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
Fix: F-52248r780145_fix

Enable "fapolicyd" using the following command: $ sudo systemctl enable --now fapolicyd

b
OL 8 must have the USBGuard installed.
RMF Control
IA-3
Severity
Medium
CCI
CCI-001958
Version
OL08-00-040139
Vuln IDs
V-248862
Rule IDs
SV-248862r986387_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.
Fix: F-52250r780151_fix

Install the USBGuard package with the following command: $ sudo yum install usbguard.x86_64

b
OL 8 must enable the USBGuard.
RMF Control
IA-3
Severity
Medium
CCI
CCI-001958
Version
OL08-00-040141
Vuln IDs
V-248864
Rule IDs
SV-248864r986388_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.
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.
RMF Control
SC-5
Severity
Medium
CCI
CCI-001095
Version
OL08-00-040150
Vuln IDs
V-248865
Rule IDs
SV-248865r958528_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
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.
RMF Control
SC-8
Severity
Medium
CCI
CCI-002418
Version
OL08-00-040159
Vuln IDs
V-248866
Rule IDs
SV-248866r958908_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
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.
RMF Control
SC-8
Severity
Medium
CCI
CCI-002418
Version
OL08-00-040160
Vuln IDs
V-248867
Rule IDs
SV-248867r958908_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
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.
RMF Control
AC-17
Severity
Medium
CCI
CCI-000068
Version
OL08-00-040161
Vuln IDs
V-248868
Rule IDs
SV-248868r958408_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. Session key regeneration limits the chances of a session key becoming compromised.
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.
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
OL08-00-040170
Vuln IDs
V-248869
Rule IDs
SV-248869r991589_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.
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.
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
OL08-00-040171
Vuln IDs
V-248870
Rule IDs
SV-248870r991589_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040172
Vuln IDs
V-248871
Rule IDs
SV-248871r991589_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.
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.
RMF Control
CM-6
Severity
Low
CCI
CCI-000366
Version
OL08-00-040180
Vuln IDs
V-248872
Rule IDs
SV-248872r991589_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.
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.
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
OL08-00-040190
Vuln IDs
V-248873
Rule IDs
SV-248873r991589_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.
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.
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
OL08-00-040200
Vuln IDs
V-248874
Rule IDs
SV-248874r991589_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040209
Vuln IDs
V-248875
Rule IDs
SV-248875r991589_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
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040210
Vuln IDs
V-248876
Rule IDs
SV-248876r991589_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
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040220
Vuln IDs
V-248877
Rule IDs
SV-248877r991589_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
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040230
Vuln IDs
V-248878
Rule IDs
SV-248878r991589_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
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040239
Vuln IDs
V-248879
Rule IDs
SV-248879r991589_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
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040240
Vuln IDs
V-248880
Rule IDs
SV-248880r991589_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
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040249
Vuln IDs
V-248881
Rule IDs
SV-248881r991589_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
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040250
Vuln IDs
V-248882
Rule IDs
SV-248882r991589_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
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040260
Vuln IDs
V-248883
Rule IDs
SV-248883r991589_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
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040261
Vuln IDs
V-248884
Rule IDs
SV-248884r991589_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
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040262
Vuln IDs
V-248885
Rule IDs
SV-248885r991589_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
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040270
Vuln IDs
V-248886
Rule IDs
SV-248886r991589_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
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040279
Vuln IDs
V-248887
Rule IDs
SV-248887r991589_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
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040280
Vuln IDs
V-248888
Rule IDs
SV-248888r991589_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
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040281
Vuln IDs
V-248889
Rule IDs
SV-248889r991589_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
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040282
Vuln IDs
V-248890
Rule IDs
SV-248890r991589_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
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040283
Vuln IDs
V-248891
Rule IDs
SV-248891r991589_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
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040284
Vuln IDs
V-248892
Rule IDs
SV-248892r991589_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
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040285
Vuln IDs
V-248893
Rule IDs
SV-248893r991589_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
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040286
Vuln IDs
V-248894
Rule IDs
SV-248894r991589_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
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040290
Vuln IDs
V-248895
Rule IDs
SV-248895r991589_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.
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'

b
The graphical display manager must not be installed on OL 8 unless approved.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040320
Vuln IDs
V-248898
Rule IDs
SV-248898r991589_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040330
Vuln IDs
V-248899
Rule IDs
SV-248899r991589_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040340
Vuln IDs
V-248900
Rule IDs
SV-248900r991589_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040341
Vuln IDs
V-248901
Rule IDs
SV-248901r991589_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040350
Vuln IDs
V-248902
Rule IDs
SV-248902r991589_rule
Restricting TFTP to a specific directory prevents remote users from copying, transferring, or overwriting system files.
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.
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
OL08-00-040360
Vuln IDs
V-248903
Rule IDs
SV-248903r991589_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040370
Vuln IDs
V-248904
Rule IDs
SV-248904r991589_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040380
Vuln IDs
V-248905
Rule IDs
SV-248905r991589_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040390
Vuln IDs
V-248906
Rule IDs
SV-248906r991589_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.
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

c
The OL 8 operating system must not have accounts configured with blank or null passwords.
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
OL08-00-010121
Vuln IDs
V-252650
Rule IDs
SV-252650r991589_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.
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.
RMF Control
CM-5
Severity
Medium
CCI
CCI-001499
Version
OL08-00-010331
Vuln IDs
V-252651
Rule IDs
SV-252651r991560_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.
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.
RMF Control
CM-5
Severity
Medium
CCI
CCI-001499
Version
OL08-00-010341
Vuln IDs
V-252652
Rule IDs
SV-252652r991560_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.
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.
RMF Control
CM-5
Severity
Medium
CCI
CCI-001499
Version
OL08-00-010351
Vuln IDs
V-252653
Rule IDs
SV-252653r991560_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.
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 not be configured to bypass password requirements for privilege escalation.
RMF Control
Severity
Medium
CCI
CCI-004895
Version
OL08-00-010385
Vuln IDs
V-252656
Rule IDs
SV-252656r1050789_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
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-020101
Vuln IDs
V-252657
Rule IDs
SV-252657r991589_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
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-020102
Vuln IDs
V-252658
Rule IDs
SV-252658r991589_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.
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.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-020103
Vuln IDs
V-252659
Rule IDs
SV-252659r991589_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.
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
The graphical display manager must not be the default target on OL 8 unless approved.
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
OL08-00-040321
Vuln IDs
V-252663
Rule IDs
SV-252663r991589_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.
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 must terminate idle user sessions.
RMF Control
SC-10
Severity
Medium
CCI
CCI-001133
Version
OL08-00-020035
Vuln IDs
V-257259
Rule IDs
SV-257259r970703_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.
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