Red Hat Enterprise Linux 7 Security Technical Implementation Guide

  • Version/Release: V3R14
  • Published: 2023-12-01
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This Security Technical Implementation Guide is published as a tool to improve the security of Department of Defense (DOD) information systems. The requirements are derived from the National Institute of Standards and Technology (NIST) 800-53 and related documents. Comments or proposed revisions to this document should be sent via email to the following address: [email protected].
c
The Red Hat Enterprise Linux operating system must be configured so that the file permissions, ownership, and group membership of system files and commands match the vendor values.
AU-9 - High - CCI-001494 - V-204392 - SV-204392r880752_rule
RMF Control
AU-9
Severity
High
CCI
CCI-001494
Version
RHEL-07-010010
Vuln IDs
  • V-204392
  • V-71849
Rule IDs
  • SV-204392r880752_rule
  • SV-86473
Discretionary access control is weakened if a user or group has access permissions to system files and directories greater than the default. Satisfies: SRG-OS-000257-GPOS-00098, SRG-OS-000278-GPOS-00108
Checks: C-36339r880750_chk

Verify the file permissions, ownership, and group membership of system files and commands match the vendor values. Check the default file permissions, ownership, and group membership of system files and commands with the following command: # for i in `rpm -Va | grep -E '^.{1}M|^.{5}U|^.{6}G' | cut -d " " -f 4,5`;do for j in `rpm -qf $i`;do rpm -ql $j --dump | cut -d " " -f 1,5,6,7 | grep $i;done;done /var/log/gdm 040755 root root /etc/audisp/audisp-remote.conf 0100640 root root /usr/bin/passwd 0104755 root root For each file returned, verify the current permissions, ownership, and group membership: # ls -la <filename> -rw-------. 1 root root 2017 Nov 1 10:03 /etc/audisp/audisp-remote.conf If the file is more permissive than the default permissions, this is a finding. If the file is not owned by the default owner and is not documented with the Information System Security Officer (ISSO), this is a finding. If the file is not a member of the default group and is not documented with the Information System Security Officer (ISSO), this is a finding.

Fix: F-36302r880751_fix

Run the following command to determine which package owns the file: # rpm -qf <filename> Reset the user and group ownership of files within a package with the following command: # rpm --setugids <packagename> Reset the permissions of files within a package with the following command: # rpm --setperms <packagename>

b
The Red Hat Enterprise Linux operating system must display the Standard Mandatory DoD Notice and Consent Banner before granting local or remote access to the system via a graphical user logon.
AC-8 - Medium - CCI-000048 - V-204393 - SV-204393r603261_rule
RMF Control
AC-8
Severity
Medium
CCI
CCI-000048
Version
RHEL-07-010030
Vuln IDs
  • V-204393
  • V-71859
Rule IDs
  • SV-204393r603261_rule
  • SV-86483
Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. System use notifications are required only for access via logon interfaces with human users and are not required when such human interfaces do not exist. The banner must be formatted in accordance with applicable DoD policy. Use the following verbiage for operating systems that can accommodate banners of 1300 characters: "You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details." Satisfies: SRG-OS-000023-GPOS-00006, SRG-OS-000024-GPOS-00007, SRG-OS-000228-GPOS-00088
Checks: C-4517r88371_chk

Verify the operating system displays the Standard Mandatory DoD Notice and Consent Banner before granting access to the operating system via a graphical user logon. Note: If the system does not have GNOME installed, this requirement is Not Applicable. Check to see if the operating system displays a banner at the logon screen with the following command: # grep banner-message-enable /etc/dconf/db/local.d/* banner-message-enable=true If "banner-message-enable" is set to "false" or is missing, this is a finding.

Fix: F-4517r88372_fix

Configure the operating system to display the Standard Mandatory DoD Notice and Consent Banner before granting access to the system. Note: If the system does not have GNOME 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: # touch /etc/dconf/db/local.d/01-banner-message Add the following line 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 Update the system databases: # dconf update Users must log out and back in again before the system-wide settings take effect.

b
The Red Hat Enterprise Linux operating system must display the approved Standard Mandatory DoD Notice and Consent Banner before granting local or remote access to the system via a graphical user logon.
AC-8 - Medium - CCI-000048 - V-204394 - SV-204394r603261_rule
RMF Control
AC-8
Severity
Medium
CCI
CCI-000048
Version
RHEL-07-010040
Vuln IDs
  • V-204394
  • V-71861
Rule IDs
  • SV-204394r603261_rule
  • SV-86485
Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. System use notifications are required only for access via logon interfaces with human users and are not required when such human interfaces do not exist. The banner must be formatted in accordance with applicable DoD policy. "You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details." Satisfies: SRG-OS-000023-GPOS-00006, SRG-OS-000024-GPOS-00007, SRG-OS-000228-GPOS-00088
Checks: C-4518r297478_chk

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

Fix: F-4518r297479_fix

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

b
The Red Hat Enterprise Linux operating system must display the Standard Mandatory DoD Notice and Consent Banner before granting local or remote access to the system via a command line user logon.
AC-8 - Medium - CCI-000048 - V-204395 - SV-204395r603261_rule
RMF Control
AC-8
Severity
Medium
CCI
CCI-000048
Version
RHEL-07-010050
Vuln IDs
  • V-204395
  • V-71863
Rule IDs
  • SV-204395r603261_rule
  • SV-86487
Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. System use notifications are required only for access via logon interfaces with human users and are not required when such human interfaces do not exist. The banner must be formatted in accordance with applicable DoD policy. Use the following verbiage for operating systems that can accommodate banners of 1300 characters: "You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details." Satisfies: SRG-OS-000023-GPOS-00006, SRG-OS-000024-GPOS-00007
Checks: C-4519r88377_chk

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

Fix: F-4519r88378_fix

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

b
The Red Hat Enterprise Linux operating system must enable a user session lock until that user re-establishes access using established identification and authentication procedures.
AC-11 - Medium - CCI-000056 - V-204396 - SV-204396r880746_rule
RMF Control
AC-11
Severity
Medium
CCI
CCI-000056
Version
RHEL-07-010060
Vuln IDs
  • V-204396
  • V-71891
Rule IDs
  • SV-204396r880746_rule
  • SV-86515
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. Satisfies: SRG-OS-000028-GPOS-00009, SRG-OS-000030-GPOS-00011
Checks: C-4520r880744_chk

Verify the operating system enables a user's session lock until that user re-establishes access using established identification and authentication procedures. Note: If the system does not have GNOME installed, this requirement is Not Applicable. Check to see if the screen lock is enabled with the following command: # grep -ir lock-enabled /etc/dconf/db/local.d/ | grep -v locks lock-enabled=true If the "lock-enabled" setting is missing or is not set to "true", this is a finding.

Fix: F-4520r880745_fix

Configure the operating system to enable a user's session lock until that user re-establishes 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: # touch /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: # dconf update Users must log out and back in again before the system-wide settings take effect.

b
The Red Hat Enterprise Linux operating system must uniquely identify and must authenticate users using multifactor authentication via a graphical user logon.
IA-2 - Medium - CCI-001948 - V-204397 - SV-204397r853879_rule
RMF Control
IA-2
Severity
Medium
CCI
CCI-001948
Version
RHEL-07-010061
Vuln IDs
  • V-204397
  • V-77819
Rule IDs
  • SV-204397r853879_rule
  • SV-92515
To assure accountability and prevent unauthenticated access, users must be identified and authenticated to prevent potential misuse and compromise of the system. Multifactor solutions that require devices separate from information systems gaining access include, for example, hardware tokens providing time-based or challenge-response authenticators and smart cards such as the U.S. Government Personal Identity Verification card and the DoD Common Access Card. Satisfies: SRG-OS-000375-GPOS-00161,SRG-OS-000375-GPOS-00162
Checks: C-4521r88383_chk

Verify the operating system uniquely identifies and authenticates users using multifactor authentication via a graphical user logon. Note: If the system does not have GNOME installed, this requirement is Not Applicable. Determine which profile the system database is using with the following command: # grep system-db /etc/dconf/profile/user system-db:local Note: The example is using the database local for the system, so the path is "/etc/dconf/db/local.d". This path must be modified if a database other than local is being used. # grep enable-smartcard-authentication /etc/dconf/db/local.d/* enable-smartcard-authentication=true If "enable-smartcard-authentication" is set to "false" or the keyword is missing, this is a finding.

Fix: F-4521r88384_fix

Configure the operating system to uniquely identify and authenticate users using multifactor authentication via a graphical user logon. Note: If the system does not have GNOME installed, this requirement is Not Applicable. Create a database to contain the system-wide screensaver settings (if it does not already exist) with the following command: Note: The example 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. # touch /etc/dconf/db/local.d/00-defaults Edit "[org/gnome/login-screen]" and add or update the following line: enable-smartcard-authentication=true Update the system databases: # dconf update

b
The Red Hat Enterprise Linux operating system must initiate a screensaver after a 15-minute period of inactivity for graphical user interfaces.
AC-11 - Medium - CCI-000057 - V-204398 - SV-204398r880770_rule
RMF Control
AC-11
Severity
Medium
CCI
CCI-000057
Version
RHEL-07-010070
Vuln IDs
  • V-204398
  • V-71893
Rule IDs
  • SV-204398r880770_rule
  • SV-86517
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.
Checks: C-4522r880768_chk

Verify the operating system initiates a screensaver after a 15-minute period of inactivity for graphical user interfaces. Note: If the system does not have GNOME installed, this requirement is Not Applicable. Check to see if GNOME is configured to display a screensaver after a 15 minute delay with the following command: # grep -i idle-delay /etc/dconf/db/local.d/* idle-delay=uint32 900 If the "idle-delay" setting is missing or is not set to "900" or less, this is a finding.

Fix: F-4522r880769_fix

Configure the operating system to initiate a screensaver after a 15-minute period of inactivity for graphical user interfaces. Create a database to contain the system-wide screensaver settings (if it does not already exist) with the following command: # touch /etc/dconf/db/local.d/00-screensaver Edit /etc/dconf/db/local.d/00-screensaver and add or update the following lines: [org/gnome/desktop/session] # Set the lock time out to 900 seconds before the session is considered idle idle-delay=uint32 900 You must include the "uint32" along with the integer key values as shown. Update the system databases: # dconf update Users must log out and back in again before the system-wide settings take effect.

b
The Red Hat Enterprise Linux operating system must prevent a user from overriding the screensaver lock-delay setting for the graphical user interface.
AC-11 - Medium - CCI-000057 - V-204399 - SV-204399r880773_rule
RMF Control
AC-11
Severity
Medium
CCI
CCI-000057
Version
RHEL-07-010081
Vuln IDs
  • V-204399
  • V-73155
Rule IDs
  • SV-204399r880773_rule
  • SV-87807
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.
Checks: C-4523r880771_chk

Verify the operating system prevents a user from overriding a screensaver lock after a 15-minute period of inactivity for graphical user interfaces. Note: If the system does not have GNOME installed, this requirement is Not Applicable. Determine which profile the system database is using with the following command: # grep system-db /etc/dconf/profile/user system-db:local Check for the lock delay setting with the following command: Note: The example below is using the database "local" for the system, so the path is "/etc/dconf/db/local.d". This path must be modified if a database other than "local" is being used. # grep -i lock-delay /etc/dconf/db/local.d/locks/* /org/gnome/desktop/screensaver/lock-delay If the command does not return a result, this is a finding.

Fix: F-4523r880772_fix

Configure the operating system to prevent a user from overriding a screensaver lock after a 15-minute period of inactivity for graphical user interfaces. Create a database to contain the system-wide screensaver settings (if it does not already exist) with the following command: 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. # touch /etc/dconf/db/local.d/locks/session Add the setting to lock the screensaver lock delay: /org/gnome/desktop/screensaver/lock-delay

b
The Red Hat Enterprise Linux operating system must prevent a user from overriding the session idle-delay setting for the graphical user interface.
AC-11 - Medium - CCI-000057 - V-204400 - SV-204400r880776_rule
RMF Control
AC-11
Severity
Medium
CCI
CCI-000057
Version
RHEL-07-010082
Vuln IDs
  • V-204400
  • V-73157
Rule IDs
  • SV-204400r880776_rule
  • SV-87809
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.
Checks: C-4524r880774_chk

Verify the operating system prevents a user from overriding session idle delay after a 15-minute period of inactivity for graphical user interfaces. Note: If the system does not have GNOME installed, this requirement is Not Applicable. Determine which profile the system database is using with the following command: # grep system-db /etc/dconf/profile/user system-db:local Check for the session idle delay setting with the following command: Note: The example below is using the database "local" for the system, so the path is "/etc/dconf/db/local.d". This path must be modified if a database other than "local" is being used. # grep -i idle-delay /etc/dconf/db/local.d/locks/* /org/gnome/desktop/session/idle-delay If the command does not return a result, this is a finding.

Fix: F-4524r880775_fix

Configure the operating system to prevent a user from overriding a session lock after a 15-minute period of inactivity for graphical user interfaces. Create a database to contain the system-wide screensaver settings (if it does not already exist) with the following command: 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. # touch /etc/dconf/db/local.d/locks/session Add the setting to lock the session idle delay: /org/gnome/desktop/session/idle-delay

b
The Red Hat Enterprise Linux operating system must initiate a session lock for the screensaver after a period of inactivity for graphical user interfaces.
AC-11 - Medium - CCI-000057 - V-204402 - SV-204402r880782_rule
RMF Control
AC-11
Severity
Medium
CCI
CCI-000057
Version
RHEL-07-010100
Vuln IDs
  • V-204402
  • V-71899
Rule IDs
  • SV-204402r880782_rule
  • SV-86523
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.
Checks: C-4526r880780_chk

Verify the operating system initiates a session lock after a 15-minute period of inactivity for graphical user interfaces. Note: If the system does not have a GNOME installed, this requirement is Not Applicable. Check for the session lock settings with the following commands: # grep -i idle-activation-enabled /etc/dconf/db/local.d/* idle-activation-enabled=true If "idle-activation-enabled" is not set to "true", this is a finding.

Fix: F-4526r880781_fix

Configure the operating system to initiate a session lock after a 15-minute period of inactivity for graphical user interfaces. Create a database to contain the system-wide screensaver settings (if it does not already exist) with the following command: # touch /etc/dconf/db/local.d/00-screensaver Add the setting to enable screensaver locking after 15 minutes of inactivity: [org/gnome/desktop/screensaver] idle-activation-enabled=true Update the system databases: # dconf update Users must log out and back in again before the system-wide settings take effect.

b
The Red Hat Enterprise Linux operating system must prevent a user from overriding the screensaver idle-activation-enabled setting for the graphical user interface.
AC-11 - Medium - CCI-000057 - V-204403 - SV-204403r880785_rule
RMF Control
AC-11
Severity
Medium
CCI
CCI-000057
Version
RHEL-07-010101
Vuln IDs
  • V-204403
  • V-78997
Rule IDs
  • SV-204403r880785_rule
  • SV-93703
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. The ability to enable/disable a session lock is given to the user by default. Disabling the user's ability to disengage the graphical user interface session lock provides the assurance that all sessions will lock after the specified period of time.
Checks: C-4527r880783_chk

Verify the operating system prevents a user from overriding the screensaver idle-activation-enabled setting for the graphical user interface. Note: If the system does not have GNOME installed, this requirement is Not Applicable. Determine which profile the system database is using with the following command: # grep system-db /etc/dconf/profile/user system-db:local Check for the idle-activation-enabled setting with the following command: Note: The example below is using the database "local" for the system, so the path is "/etc/dconf/db/local.d". This path must be modified if a database other than "local" is being used. # grep -i idle-activation-enabled /etc/dconf/db/local.d/locks/* /org/gnome/desktop/screensaver/idle-activation-enabled If the command does not return a result, this is a finding.

Fix: F-4527r880784_fix

Configure the operating system to prevent a user from overriding a screensaver lock after a 15-minute period of inactivity for graphical user interfaces. Create a database to contain the system-wide screensaver settings (if it does not already exist) with the following command: 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. # touch /etc/dconf/db/local.d/locks/session Add the setting to lock the screensaver idle-activation-enabled setting: /org/gnome/desktop/screensaver/idle-activation-enabled

b
The Red Hat Enterprise Linux operating system must initiate a session lock for graphical user interfaces when the screensaver is activated.
AC-11 - Medium - CCI-000057 - V-204404 - SV-204404r880788_rule
RMF Control
AC-11
Severity
Medium
CCI
CCI-000057
Version
RHEL-07-010110
Vuln IDs
  • V-204404
  • V-71901
Rule IDs
  • SV-204404r880788_rule
  • SV-86525
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.
Checks: C-4528r880786_chk

Verify the operating system initiates a session lock a for graphical user interfaces when the screensaver is activated. Note: If the system does not have GNOME installed, this requirement is Not Applicable. If GNOME is installed, check to see a session lock occurs when the screensaver is activated with the following command: # grep -i lock-delay /etc/dconf/db/local.d/* lock-delay=uint32 5 If the "lock-delay" setting is missing, or is not set to "5" or less, this is a finding.

Fix: F-4528r880787_fix

Configure the operating system to initiate a session lock for graphical user interfaces when a screensaver is activated. Create a database to contain the system-wide screensaver settings (if it does not already exist) with the following command: # touch /etc/dconf/db/local.d/00-screensaver Add the setting to enable session locking when a screensaver is activated: [org/gnome/desktop/screensaver] lock-delay=uint32 5 The "uint32" must be included along with the integer key values as shown. Update the system databases: # dconf update Users must log out and back in again before the system-wide settings take effect.

b
The Red Hat Enterprise Linux operating system must be configured so that /etc/pam.d/passwd implements /etc/pam.d/system-auth when changing passwords.
IA-5 - Medium - CCI-000192 - V-204405 - SV-204405r603261_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000192
Version
RHEL-07-010118
Vuln IDs
  • V-204405
  • V-81003
Rule IDs
  • SV-204405r603261_rule
  • SV-95715
Pluggable authentication modules (PAM) allow for a modular approach to integrating authentication methods. PAM operates in a top-down processing model and if the modules are not listed in the correct order, an important security function could be bypassed if stack entries are not centralized.
Checks: C-4529r88407_chk

Verify that /etc/pam.d/passwd is configured to use /etc/pam.d/system-auth when changing passwords: # cat /etc/pam.d/passwd | grep -i substack | grep -i system-auth password substack system-auth If no results are returned, the line is commented out, this is a finding.

Fix: F-4529r88408_fix

Configure PAM to utilize /etc/pam.d/system-auth when changing passwords. Add the following line to "/etc/pam.d/passwd" (or modify the line to have the required value): password substack system-auth

b
The Red Hat Enterprise Linux operating system must be configured so that when passwords are changed or new passwords are established, pwquality must be used.
IA-5 - Medium - CCI-000192 - V-204406 - SV-204406r902704_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000192
Version
RHEL-07-010119
Vuln IDs
  • V-204406
  • V-73159
Rule IDs
  • SV-204406r902704_rule
  • SV-87811
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.
Checks: C-4530r902702_chk

Verify the operating system uses "pwquality" to enforce the password complexity rules. Check for the use of "pwquality" with the following command: # cat /etc/pam.d/system-auth | grep pam_pwquality password requisite pam_pwquality.so retry=3 If the command does not return an uncommented line containing the value "pam_pwquality.so" as shown, this is a finding. If the value of "retry" is set to "0" or greater than "3", this is a finding.

Fix: F-4530r902703_fix

Configure the operating system to use "pwquality" to enforce password complexity rules. Add the following line to "/etc/pam.d/system-auth" (or modify the line to have the required value): password requisite pam_pwquality.so retry=3 Note: The value of "retry" should be between "1" and "3".

b
The Red Hat Enterprise Linux operating system must be configured so that when passwords are changed or new passwords are established, the new password must contain at least one upper-case character.
IA-5 - Medium - CCI-000192 - V-204407 - SV-204407r603261_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000192
Version
RHEL-07-010120
Vuln IDs
  • V-204407
  • V-71903
Rule IDs
  • SV-204407r603261_rule
  • SV-86527
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.
Checks: C-4531r88413_chk

Note: The value to require a number of upper-case characters to be set is expressed as a negative number in "/etc/security/pwquality.conf". Check the value for "ucredit" in "/etc/security/pwquality.conf" with the following command: # grep ucredit /etc/security/pwquality.conf ucredit = -1 If the value of "ucredit" is not set to a negative value, this is a finding.

Fix: F-4531r88414_fix

Configure the operating system to enforce password complexity by requiring that at least one upper-case character be used by setting the "ucredit" option. Add the following line to "/etc/security/pwquality.conf" (or modify the line to have the required value): ucredit = -1

b
The Red Hat Enterprise Linux operating system must be configured so that when passwords are changed or new passwords are established, the new password must contain at least one lower-case character.
IA-5 - Medium - CCI-000193 - V-204408 - SV-204408r603261_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000193
Version
RHEL-07-010130
Vuln IDs
  • V-204408
  • V-71905
Rule IDs
  • SV-204408r603261_rule
  • SV-86529
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.
Checks: C-4532r88416_chk

Note: The value to require a number of lower-case characters to be set is expressed as a negative number in "/etc/security/pwquality.conf". Check the value for "lcredit" in "/etc/security/pwquality.conf" with the following command: # grep lcredit /etc/security/pwquality.conf lcredit = -1 If the value of "lcredit" is not set to a negative value, this is a finding.

Fix: F-4532r88417_fix

Configure the system to require at least one lower-case character when creating or changing a password. Add or modify the following line in "/etc/security/pwquality.conf": lcredit = -1

b
The Red Hat Enterprise Linux operating system must be configured so that when passwords are changed or new passwords are assigned, the new password must contain at least one numeric character.
IA-5 - Medium - CCI-000194 - V-204409 - SV-204409r603261_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000194
Version
RHEL-07-010140
Vuln IDs
  • V-204409
  • V-71907
Rule IDs
  • SV-204409r603261_rule
  • SV-86531
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.
Checks: C-4533r88419_chk

Note: The value to require a number of numeric characters to be set is expressed as a negative number in "/etc/security/pwquality.conf". Check the value for "dcredit" in "/etc/security/pwquality.conf" with the following command: # grep dcredit /etc/security/pwquality.conf dcredit = -1 If the value of "dcredit" is not set to a negative value, this is a finding.

Fix: F-4533r88420_fix

Configure the operating system to enforce password complexity by requiring that at least one numeric character be used by setting the "dcredit" option. Add the following line to /etc/security/pwquality.conf (or modify the line to have the required value): dcredit = -1

b
The Red Hat Enterprise Linux operating system must be configured so that when passwords are changed or new passwords are established, the new password must contain at least one special character.
IA-5 - Medium - CCI-001619 - V-204410 - SV-204410r603261_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-001619
Version
RHEL-07-010150
Vuln IDs
  • V-204410
  • V-71909
Rule IDs
  • SV-204410r603261_rule
  • SV-86533
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.
Checks: C-4534r88422_chk

Verify the operating system enforces password complexity by requiring that at least one special character be used. Note: The value to require a number of special characters to be set is expressed as a negative number in "/etc/security/pwquality.conf". Check the value for "ocredit" in "/etc/security/pwquality.conf" with the following command: # grep ocredit /etc/security/pwquality.conf ocredit=-1 If the value of "ocredit" is not set to a negative value, this is a finding.

Fix: F-4534r88423_fix

Configure the operating system to enforce password complexity by requiring that at least one special character be used by setting the "ocredit" option. Add the following line to "/etc/security/pwquality.conf" (or modify the line to have the required value): ocredit = -1

b
The Red Hat Enterprise Linux operating system must be configured so that when passwords are changed a minimum of eight of the total number of characters must be changed.
IA-5 - Medium - CCI-000195 - V-204411 - SV-204411r603261_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000195
Version
RHEL-07-010160
Vuln IDs
  • V-204411
  • V-71911
Rule IDs
  • SV-204411r603261_rule
  • SV-86535
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.
Checks: C-4535r88425_chk

The "difok" option sets the number of characters in a password that must not be present in the old password. Check for the value of the "difok" option in "/etc/security/pwquality.conf" with the following command: # grep difok /etc/security/pwquality.conf difok = 8 If the value of "difok" is set to less than "8", this is a finding.

Fix: F-4535r88426_fix

Configure the operating system to require the change of at least eight of the total number of characters when passwords are changed by setting the "difok" option. Add the following line to "/etc/security/pwquality.conf" (or modify the line to have the required value): difok = 8

b
The Red Hat Enterprise Linux operating system must be configured so that when passwords are changed a minimum of four character classes must be changed.
IA-5 - Medium - CCI-000195 - V-204412 - SV-204412r603261_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000195
Version
RHEL-07-010170
Vuln IDs
  • V-204412
  • V-71913
Rule IDs
  • SV-204412r603261_rule
  • SV-86537
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.
Checks: C-4536r88428_chk

The "minclass" option sets the minimum number of required classes of characters for the new password (digits, upper-case, lower-case, others). Check for the value of the "minclass" option in "/etc/security/pwquality.conf" with the following command: # grep minclass /etc/security/pwquality.conf minclass = 4 If the value of "minclass" is set to less than "4", this is a finding.

Fix: F-4536r88429_fix

Configure the operating system to require the change of at least four character classes when passwords are changed by setting the "minclass" option. Add the following line to "/etc/security/pwquality.conf conf" (or modify the line to have the required value): minclass = 4

b
The Red Hat Enterprise Linux operating system must be configured so that when passwords are changed the number of repeating consecutive characters must not be more than three characters.
IA-5 - Medium - CCI-000195 - V-204413 - SV-204413r603261_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000195
Version
RHEL-07-010180
Vuln IDs
  • V-204413
  • V-71915
Rule IDs
  • SV-204413r603261_rule
  • SV-86539
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.
Checks: C-4537r88431_chk

The "maxrepeat" option sets the maximum number of allowed same consecutive characters in a new password. Check for the value of the "maxrepeat" option in "/etc/security/pwquality.conf" with the following command: # grep maxrepeat /etc/security/pwquality.conf maxrepeat = 3 If the value of "maxrepeat" is set to more than "3", this is a finding.

Fix: F-4537r88432_fix

Configure the operating system to require the change of the number of repeating consecutive characters when passwords are changed by setting the "maxrepeat" option. Add the following line to "/etc/security/pwquality.conf conf" (or modify the line to have the required value): maxrepeat = 3

b
The Red Hat Enterprise Linux operating system must be configured so that when passwords are changed the number of repeating characters of the same character class must not be more than four characters.
IA-5 - Medium - CCI-000195 - V-204414 - SV-204414r809186_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000195
Version
RHEL-07-010190
Vuln IDs
  • V-204414
  • V-71917
Rule IDs
  • SV-204414r809186_rule
  • SV-86541
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.
Checks: C-4538r809185_chk

The "maxclassrepeat" option sets the maximum number of allowed same consecutive characters in the same class in the new password. Check for the value of the "maxclassrepeat" option in "/etc/security/pwquality.conf" with the following command: $ sudo grep maxclassrepeat /etc/security/pwquality.conf maxclassrepeat = 4 If the value of "maxclassrepeat" is set to "0", more than "4" or is commented out, this is a finding.

Fix: F-4538r88435_fix

Configure the operating system 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 the following line to "/etc/security/pwquality.conf" conf (or modify the line to have the required value): maxclassrepeat = 4

b
The Red Hat Enterprise Linux operating system must be configured so that the PAM system service is configured to store only encrypted representations of passwords.
IA-5 - Medium - CCI-000196 - V-204415 - SV-204415r917816_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000196
Version
RHEL-07-010200
Vuln IDs
  • V-204415
  • V-71919
Rule IDs
  • SV-204415r917816_rule
  • SV-86543
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. Passwords encrypted with a weak algorithm are no more protected than if they are kept in plain text.
Checks: C-4539r880831_chk

Verify the PAM system service is configured to store only encrypted representations of passwords. The strength of encryption that must be used to hash passwords for all accounts is SHA512. Check that the system is configured to create SHA512 hashed passwords with the following command: # grep password /etc/pam.d/system-auth /etc/pam.d/password-auth Outcome should look like following: /etc/pam.d/system-auth-ac:password sufficient pam_unix.so sha512 shadow try_first_pass use_authtok /etc/pam.d/password-auth:password sufficient pam_unix.so sha512 shadow try_first_pass use_authtok If the "/etc/pam.d/system-auth" and "/etc/pam.d/password-auth" configuration files allow for password hashes other than SHA512 to be used, this is a finding.

Fix: F-4539r917815_fix

Configure the operating system to store only SHA512 encrypted representations of passwords. Add the following line in "/etc/pam.d/system-auth": password sufficient pam_unix.so sha512 shadow try_first_pass use_authtok Add the following line in "/etc/pam.d/password-auth": password sufficient pam_unix.so sha512 shadow try_first_pass use_authtok Note: Per requirement RHEL-07-010199, RHEL 7 must be configured to not overwrite custom authentication configuration settings while using the authconfig utility; otherwise, manual changes to the listed files will be overwritten whenever the authconfig utility is used.

b
The Red Hat Enterprise Linux operating system must be configured to use the shadow file to store only encrypted representations of passwords.
IA-5 - Medium - CCI-000196 - V-204416 - SV-204416r877397_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000196
Version
RHEL-07-010210
Vuln IDs
  • V-204416
  • V-71921
Rule IDs
  • SV-204416r877397_rule
  • SV-86545
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. Passwords encrypted with a weak algorithm are no more protected than if they are kept in plain text.
Checks: C-4540r88440_chk

Verify the system's shadow file is configured to store only encrypted representations of passwords. The strength of encryption that must be used to hash passwords for all accounts is SHA512. Check that the system is configured to create SHA512 hashed passwords with the following command: # grep -i encrypt /etc/login.defs ENCRYPT_METHOD SHA512 If the "/etc/login.defs" configuration file does not exist or allows for password hashes other than SHA512 to be used, this is a finding.

Fix: F-4540r88441_fix

Configure the operating system to store only SHA512 encrypted representations of passwords. Add or update the following line in "/etc/login.defs": ENCRYPT_METHOD SHA512

b
The Red Hat Enterprise Linux operating system must be configured so that user and group account administration utilities are configured to store only encrypted representations of passwords.
IA-5 - Medium - CCI-000196 - V-204417 - SV-204417r877397_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000196
Version
RHEL-07-010220
Vuln IDs
  • V-204417
  • V-71923
Rule IDs
  • SV-204417r877397_rule
  • SV-86547
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. Passwords encrypted with a weak algorithm are no more protected than if they are kept in plain text.
Checks: C-4541r88443_chk

Verify the user and group account administration utilities are configured to store only encrypted representations of passwords. The strength of encryption that must be used to hash passwords for all accounts is "SHA512". Check that the system is configured to create "SHA512" hashed passwords with the following command: # grep -i sha512 /etc/libuser.conf crypt_style = sha512 If the "crypt_style" variable is not set to "sha512", is not in the defaults section, is commented out, or does not exist, this is a finding.

Fix: F-4541r88444_fix

Configure the operating system to store only SHA512 encrypted representations of passwords. Add or update the following line in "/etc/libuser.conf" in the [defaults] section: crypt_style = sha512

b
The Red Hat Enterprise Linux operating system must be configured so that passwords for new users are restricted to a 24 hours/1 day minimum lifetime.
IA-5 - Medium - CCI-000198 - V-204418 - SV-204418r603261_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000198
Version
RHEL-07-010230
Vuln IDs
  • V-204418
  • V-71925
Rule IDs
  • SV-204418r603261_rule
  • SV-86549
Enforcing a minimum password lifetime helps to prevent repeated password changes to defeat the password reuse or history enforcement requirement. If users are allowed to immediately and continually change their password, the password could be repeatedly changed in a short period of time to defeat the organization's policy regarding password reuse.
Checks: C-4542r88446_chk

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

Fix: F-4542r88447_fix

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

b
The Red Hat Enterprise Linux operating system must be configured so that passwords are restricted to a 24 hours/1 day minimum lifetime.
IA-5 - Medium - CCI-000198 - V-204419 - SV-204419r603261_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000198
Version
RHEL-07-010240
Vuln IDs
  • V-204419
  • V-71927
Rule IDs
  • SV-204419r603261_rule
  • SV-86551
Enforcing a minimum password lifetime helps to prevent repeated password changes to defeat the password reuse or history enforcement requirement. If users are allowed to immediately and continually change their password, the password could be repeatedly changed in a short period of time to defeat the organization's policy regarding password reuse.
Checks: C-4543r88449_chk

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

Fix: F-4543r88450_fix

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

b
The Red Hat Enterprise Linux operating system must be configured so that passwords for new users are restricted to a 60-day maximum lifetime.
IA-5 - Medium - CCI-000199 - V-204420 - SV-204420r603261_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000199
Version
RHEL-07-010250
Vuln IDs
  • V-204420
  • V-71929
Rule IDs
  • SV-204420r603261_rule
  • SV-86553
Any password, no matter how complex, can eventually be cracked. Therefore, passwords need to be changed periodically. If the operating system does not limit the lifetime of passwords and force users to change their passwords, there is the risk that the operating system passwords could be compromised.
Checks: C-4544r88452_chk

If passwords are not being used for authentication, this is Not Applicable. Verify the operating system enforces a 60-day maximum password lifetime restriction for new user accounts. Check for the value of "PASS_MAX_DAYS" in "/etc/login.defs" with the following command: # grep -i pass_max_days /etc/login.defs PASS_MAX_DAYS 60 If the "PASS_MAX_DAYS" parameter value is not 60 or less, or is commented out, this is a finding.

Fix: F-4544r88453_fix

Configure the operating system to enforce a 60-day maximum password lifetime restriction. Add the following line in "/etc/login.defs" (or modify the line to have the required value): PASS_MAX_DAYS 60

b
The Red Hat Enterprise Linux operating system must be configured so that existing passwords are restricted to a 60-day maximum lifetime.
IA-5 - Medium - CCI-000199 - V-204421 - SV-204421r603261_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000199
Version
RHEL-07-010260
Vuln IDs
  • V-204421
  • V-71931
Rule IDs
  • SV-204421r603261_rule
  • SV-86555
Any password, no matter how complex, can eventually be cracked. Therefore, passwords need to be changed periodically. If the operating system does not limit the lifetime of passwords and force users to change their passwords, there is the risk that the operating system passwords could be compromised.
Checks: C-4545r88455_chk

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

Fix: F-4545r88456_fix

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

b
The Red Hat Enterprise Linux operating system must be configured so that passwords are prohibited from reuse for a minimum of five generations.
IA-5 - Medium - CCI-000200 - V-204422 - SV-204422r917818_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000200
Version
RHEL-07-010270
Vuln IDs
  • V-204422
  • V-71933
Rule IDs
  • SV-204422r917818_rule
  • SV-86557
Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. If the information system or application allows the user to consecutively reuse their password when that password has exceeded its defined lifetime, the end result is a password that is not changed per policy requirements.
Checks: C-4546r880834_chk

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

Fix: F-4546r917817_fix

Configure the operating system to prohibit password reuse for a minimum of five generations. Add the following line in "/etc/pam.d/system-auth" (or modify the line to have the required value): password requisite pam_pwhistory.so remember=5 retry=3 Add the following line in "/etc/pam.d/password-auth" (or modify the line to have the required value): password requisite pam_pwhistory.so use_authtok remember=5 retry=3 Note: Per requirement RHEL-07-010199, RHEL 7 must be configured to not overwrite custom authentication configuration settings while using the authconfig utility; otherwise, manual changes to the listed files will be overwritten whenever the authconfig utility is used.

b
The Red Hat Enterprise Linux operating system must be configured so that passwords are a minimum of 15 characters in length.
IA-5 - Medium - CCI-000205 - V-204423 - SV-204423r603261_rule
RMF Control
IA-5
Severity
Medium
CCI
CCI-000205
Version
RHEL-07-010280
Vuln IDs
  • V-204423
  • V-71935
Rule IDs
  • SV-204423r603261_rule
  • SV-86559
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 exponentially increase the time and/or resources required to compromise the password.
Checks: C-4547r88461_chk

Verify the operating system enforces a minimum 15-character password length. The "minlen" option sets the minimum number of characters in a new password. Check for the value of the "minlen" option in "/etc/security/pwquality.conf" with the following command: # grep minlen /etc/security/pwquality.conf minlen = 15 If the command does not return a "minlen" value of 15 or greater, this is a finding.

Fix: F-4547r88462_fix

Configure operating system to enforce a minimum 15-character password length. Add the following line to "/etc/security/pwquality.conf" (or modify the line to have the required value): minlen = 15

c
The Red Hat Enterprise Linux operating system must not allow accounts configured with blank or null passwords.
CM-6 - High - CCI-000366 - V-204424 - SV-204424r880839_rule
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
RHEL-07-010290
Vuln IDs
  • V-204424
  • V-71937
Rule IDs
  • SV-204424r880839_rule
  • SV-86561
If an account has an empty password, anyone could log on and run commands with the privileges of that account. Accounts with empty passwords should never be used in operational environments.
Checks: C-4548r880837_chk

To verify that null passwords cannot be used, run the following command: # grep nullok /etc/pam.d/system-auth /etc/pam.d/password-auth If this produces any output, it may be possible to log on with accounts with empty passwords. If null passwords can be used, this is a finding.

Fix: F-4548r880838_fix

If an account is configured for password authentication but does not have an assigned password, it may be possible to log on to the account without authenticating. Remove any instances of the "nullok" option in "/etc/pam.d/system-auth" and "/etc/pam.d/password-auth" to prevent logons with empty passwords. Note: Per requirement RHEL-07-010199, RHEL 7 must be configured to not overwrite custom authentication configuration settings while using the authconfig utility, otherwise manual changes to the listed files will be overwritten whenever the authconfig utility is used.

c
The Red Hat Enterprise Linux operating system must be configured so that the SSH daemon does not allow authentication using an empty password.
IA-2 - High - CCI-000766 - V-204425 - SV-204425r603261_rule
RMF Control
IA-2
Severity
High
CCI
CCI-000766
Version
RHEL-07-010300
Vuln IDs
  • V-204425
  • V-71939
Rule IDs
  • SV-204425r603261_rule
  • SV-86563
Configuring this setting for the SSH daemon provides additional assurance that remote logon via SSH will require a password, even in the event of misconfiguration elsewhere.
Checks: C-4549r88467_chk

To determine how the SSH daemon's "PermitEmptyPasswords" option is set, run the following command: # grep -i PermitEmptyPasswords /etc/ssh/sshd_config PermitEmptyPasswords no If no line, a commented line, or a line indicating the value "no" is returned, the required value is set. If the required value is not set, this is a finding.

Fix: F-4549r88468_fix

To explicitly disallow remote logon from accounts with empty passwords, add or correct the following line in "/etc/ssh/sshd_config": PermitEmptyPasswords no The SSH service must be restarted for changes to take effect. Any accounts with empty passwords should be disabled immediately, and PAM configuration should prevent users from being able to assign themselves empty passwords.

b
The Red Hat Enterprise Linux operating system must disable account identifiers (individuals, groups, roles, and devices) if the password expires.
IA-4 - Medium - CCI-000795 - V-204426 - SV-204426r928568_rule
RMF Control
IA-4
Severity
Medium
CCI
CCI-000795
Version
RHEL-07-010310
Vuln IDs
  • V-204426
  • V-71941
Rule IDs
  • SV-204426r928568_rule
  • SV-86565
Inactive identifiers pose a risk to systems and applications because attackers may exploit an inactive identifier and potentially obtain undetected access to the system. Owners of inactive accounts will not notice if unauthorized access to their user account has been obtained. Operating systems need to track periods of inactivity and disable application identifiers after 35 days of inactivity.
Checks: C-4550r928566_chk

If passwords are not being used for authentication, this is Not Applicable. Verify the operating system disables account identifiers (individuals, groups, roles, and devices) after the password has expired with the following command: # grep -i inactive /etc/default/useradd INACTIVE=35 If "INACTIVE" is set to "-1", a value greater than "35", is commented out, or is not defined, this is a finding.

Fix: F-4550r928567_fix

Configure the operating system to disable account identifiers (individuals, groups, roles, and devices) 35 days after the password has expired. Add the following line to "/etc/default/useradd" (or modify the line to have the required value): INACTIVE=35 DOD recommendation is 35 days, but a lower value is acceptable. The value "-1" will disable this feature, and "0" will disable the account immediately after the password expires.

b
The Red Hat Enterprise Linux operating system must be configured to lock accounts for a minimum of 15 minutes after three unsuccessful logon attempts within a 15-minute timeframe.
AC-7 - Medium - CCI-000044 - V-204427 - SV-204427r880842_rule
RMF Control
AC-7
Severity
Medium
CCI
CCI-000044
Version
RHEL-07-010320
Vuln IDs
  • V-204427
  • V-71943
Rule IDs
  • SV-204427r880842_rule
  • SV-86567
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-forcing, is reduced. Limits are imposed by locking the account. Satisfies: SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005
Checks: C-4551r880840_chk

Check that the system locks an account for a minimum of 15 minutes after three unsuccessful logon attempts within a period of 15 minutes with the following command: # grep pam_faillock.so /etc/pam.d/password-auth auth required pam_faillock.so preauth silent audit deny=3 even_deny_root fail_interval=900 unlock_time=900 auth [default=die] pam_faillock.so authfail audit deny=3 even_deny_root fail_interval=900 unlock_time=900 account required pam_faillock.so If the "deny" parameter is set to "0" or a value greater than "3" on both "auth" lines with the "pam_faillock.so" module, or is missing from these lines, this is a finding. If the "even_deny_root" parameter is not set on both "auth" lines with the "pam_faillock.so" module, or is missing from these lines, this is a finding. If the "fail_interval" parameter is set to "0" or is set to a value less than "900" on both "auth" lines with the "pam_faillock.so" module, or is missing from these lines, this is a finding. If the "unlock_time" parameter is not set to "0", "never", or is set to a value less than "900" on both "auth" lines with the "pam_faillock.so" module, or is missing from these lines, this is a finding. Note: The maximum configurable value for "unlock_time" is "604800". If any line referencing the "pam_faillock.so" module is commented out, this is a finding. # grep pam_faillock.so /etc/pam.d/system-auth auth required pam_faillock.so preauth silent audit deny=3 even_deny_root fail_interval=900 unlock_time=900 auth [default=die] pam_faillock.so authfail audit deny=3 even_deny_root fail_interval=900 unlock_time=900 account required pam_faillock.so If the "deny" parameter is set to "0" or a value greater than "3" on both "auth" lines with the "pam_faillock.so" module, or is missing from these lines, this is a finding. If the "even_deny_root" parameter is not set on both "auth" lines with the "pam_faillock.so" module, or is missing from these lines, this is a finding. If the "fail_interval" parameter is set to "0" or is set to a value less than "900" on both "auth" lines with the "pam_faillock.so" module, or is missing from these lines, this is a finding. If the "unlock_time" parameter is not set to "0", "never", or is set to a value less than "900" on both "auth" lines with the "pam_faillock.so" module or is missing from these lines, this is a finding. Note: The maximum configurable value for "unlock_time" is "604800". If any line referencing the "pam_faillock.so" module is commented out, this is a finding.

Fix: F-4551r880841_fix

Configure the operating system to lock an account for the maximum period when three unsuccessful logon attempts in 15 minutes are made. 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 silent audit deny=3 even_deny_root fail_interval=900 unlock_time=900 auth sufficient pam_unix.so try_first_pass auth [default=die] pam_faillock.so authfail audit deny=3 even_deny_root fail_interval=900 unlock_time=900 account required pam_faillock.so Note: Per requirement RHEL-07-010199, RHEL 7 must be configured to not overwrite custom authentication configuration settings while using the authconfig utility, otherwise manual changes to the listed files will be overwritten whenever the authconfig utility is used.

b
The Red Hat Enterprise Linux operating system must lock the associated account after three unsuccessful root logon attempts are made within a 15-minute period.
AC-7 - Medium - CCI-002238 - V-204428 - SV-204428r880845_rule
RMF Control
AC-7
Severity
Medium
CCI
CCI-002238
Version
RHEL-07-010330
Vuln IDs
  • V-204428
  • V-71945
Rule IDs
  • SV-204428r880845_rule
  • SV-86569
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute forcing, is reduced. Limits are imposed by locking the account. Satisfies: SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005
Checks: C-4552r880843_chk

Verify the operating system automatically locks the root account, for a minimum of 15 minutes, when three unsuccessful logon attempts in 15 minutes are made. # grep pam_faillock.so /etc/pam.d/password-auth auth required pam_faillock.so preauth silent audit deny=3 even_deny_root fail_interval=900 unlock_time=900 auth [default=die] pam_faillock.so authfail audit deny=3 even_deny_root fail_interval=900 unlock_time=900 account required pam_faillock.so If the "even_deny_root" setting is not defined on both lines with the "pam_faillock.so" module, is commented out, or is missing from a line, this is a finding. # grep pam_faillock.so /etc/pam.d/system-auth auth required pam_faillock.so preauth silent audit deny=3 even_deny_root fail_interval=900 unlock_time=900 auth [default=die] pam_faillock.so authfail audit deny=3 even_deny_root fail_interval=900 unlock_time=900 account required pam_faillock.so If the "even_deny_root" setting is not defined on both lines with the "pam_faillock.so" module, is commented out, or is missing from a line, this is a finding.

Fix: F-4552r880844_fix

Configure the operating system to automatically lock the root account, for a minimum of 15 minutes, when three unsuccessful logon attempts in 15 minutes are made. Modify the first three lines of the auth section and the first line of the account section 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 silent audit deny=3 even_deny_root fail_interval=900 unlock_time=900 auth sufficient pam_unix.so try_first_pass auth [default=die] pam_faillock.so authfail audit deny=3 even_deny_root fail_interval=900 unlock_time=900 account required pam_faillock.so Note: Per requirement RHEL-07-010199, RHEL 7 must be configured to not overwrite custom authentication configuration settings while using the authconfig utility, otherwise manual changes to the listed files will be overwritten whenever the authconfig utility is used.

b
The Red Hat Enterprise Linux operating system must be configured so that users must provide a password for privilege escalation.
IA-11 - Medium - CCI-002038 - V-204429 - SV-204429r861003_rule
RMF Control
IA-11
Severity
Medium
CCI
CCI-002038
Version
RHEL-07-010340
Vuln IDs
  • V-204429
  • V-71947
Rule IDs
  • SV-204429r861003_rule
  • SV-86571
Without re-authentication, users may access resources or perform tasks for which they do not have authorization. When operating systems provide the capability to escalate a functional capability, it is critical the user re-authenticate. Satisfies: SRG-OS-000373-GPOS-00156, SRG-OS-000373-GPOS-00157, SRG-OS-000373-GPOS-00158
Checks: C-36340r861001_chk

Verify the operating system requires users to supply a password for privilege escalation. Check the configuration of the "/etc/sudoers" and "/etc/sudoers.d/*" files with the following command: $ sudo grep -ir nopasswd /etc/sudoers /etc/sudoers.d If any occurrences of "NOPASSWD" are returned from the command and have not been documented with the Information System Security Officer (ISSO) as an organizationally defined administrative group utilizing MFA, this is a finding.

Fix: F-36303r861002_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
The Red Hat Enterprise Linux operating system must be configured so that users must re-authenticate for privilege escalation.
IA-11 - Medium - CCI-002038 - V-204430 - SV-204430r853885_rule
RMF Control
IA-11
Severity
Medium
CCI
CCI-002038
Version
RHEL-07-010350
Vuln IDs
  • V-204430
  • V-71949
Rule IDs
  • SV-204430r853885_rule
  • SV-86573
Without re-authentication, users may access resources or perform tasks for which they do not have authorization. When operating systems provide the capability to escalate a functional capability, it is critical the user reauthenticate. Satisfies: SRG-OS-000373-GPOS-00156, SRG-OS-000373-GPOS-00157, SRG-OS-000373-GPOS-00158
Checks: C-4554r88482_chk

Verify the operating system requires users to reauthenticate for privilege escalation. Check the configuration of the "/etc/sudoers" and "/etc/sudoers.d/*" files with the following command: # grep -i authenticate /etc/sudoers /etc/sudoers.d/* If any uncommented line is found with a "!authenticate" tag, this is a finding.

Fix: F-4554r88483_fix

Configure the operating system to require users to reauthenticate for privilege escalation. Check the configuration of the "/etc/sudoers" file with the following command: # visudo Remove any occurrences of "!authenticate" tags in the file. Check the configuration of the "/etc/sudoers.d/*" files with the following command: # grep -i authenticate /etc/sudoers /etc/sudoers.d/* Remove any occurrences of "!authenticate" tags in the file(s).

b
The Red Hat Enterprise Linux operating system must be configured so that the delay between logon prompts following a failed console logon attempt is at least four seconds.
CM-6 - Medium - CCI-000366 - V-204431 - SV-204431r603261_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-010430
Vuln IDs
  • V-204431
  • V-71951
Rule IDs
  • SV-204431r603261_rule
  • SV-86575
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 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 those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example, registry settings; account, file, and directory permission settings; and settings for functions, ports, protocols, services, and remote connections.
Checks: C-4555r88485_chk

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

Fix: F-4555r88486_fix

Configure the operating system 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
The Red Hat Enterprise Linux operating system must not allow an unattended or automatic logon to the system via a graphical user interface.
CM-6 - High - CCI-000366 - V-204432 - SV-204432r877377_rule
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
RHEL-07-010440
Vuln IDs
  • V-204432
  • V-71953
Rule IDs
  • SV-204432r877377_rule
  • SV-86577
Failure to restrict system access to authenticated users negatively impacts operating system security.
Checks: C-4556r88488_chk

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

Fix: F-4556r88489_fix

Configure the operating system to not allow an unattended or automatic logon to the system via a graphical user interface. Note: If the system does not have GNOME installed, this requirement is Not Applicable. 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
The Red Hat Enterprise Linux operating system must not allow an unrestricted logon to the system.
CM-6 - High - CCI-000366 - V-204433 - SV-204433r877377_rule
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
RHEL-07-010450
Vuln IDs
  • V-204433
  • V-71955
Rule IDs
  • SV-204433r877377_rule
  • SV-86579
Failure to restrict system access to authenticated users negatively impacts operating system security.
Checks: C-4557r88491_chk

Verify the operating system does not allow an unrestricted logon to the system via a graphical user interface. Note: If the system does not have GNOME installed, this requirement is Not Applicable. Check for the value of the "TimedLoginEnable" parameter in "/etc/gdm/custom.conf" file with the following command: # grep -i timedloginenable /etc/gdm/custom.conf TimedLoginEnable=false If the value of "TimedLoginEnable" is not set to "false", this is a finding.

Fix: F-4557r88492_fix

Configure the operating system to not allow an unrestricted account to log on to the system via a graphical user interface. Note: If the system does not have GNOME installed, this requirement is Not Applicable. Add or edit the line for the "TimedLoginEnable" parameter in the [daemon] section of the "/etc/gdm/custom.conf" file to "false": [daemon] TimedLoginEnable=false

b
The Red Hat Enterprise Linux operating system must not allow users to override SSH environment variables.
CM-6 - Medium - CCI-000366 - V-204434 - SV-204434r877377_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-010460
Vuln IDs
  • V-204434
  • V-71957
Rule IDs
  • SV-204434r877377_rule
  • SV-86581
Failure to restrict system access to authenticated users negatively impacts operating system security.
Checks: C-4558r88494_chk

Verify the operating system does not allow users to override environment variables to the SSH daemon. Check for the value of the "PermitUserEnvironment" keyword with the following command: # grep -i permituserenvironment /etc/ssh/sshd_config PermitUserEnvironment no If the "PermitUserEnvironment" keyword is not set to "no", is missing, or is commented out, this is a finding.

Fix: F-4558r88495_fix

Configure the operating system to not allow users to override environment variables to the SSH daemon. Edit the "/etc/ssh/sshd_config" file to uncomment or add the line for "PermitUserEnvironment" keyword and set the value to "no": PermitUserEnvironment no The SSH service must be restarted for changes to take effect.

b
The Red Hat Enterprise Linux operating system must not allow a non-certificate trusted host SSH logon to the system.
CM-6 - Medium - CCI-000366 - V-204435 - SV-204435r877377_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-010470
Vuln IDs
  • V-204435
  • V-71959
Rule IDs
  • SV-204435r877377_rule
  • SV-86583
Failure to restrict system access to authenticated users negatively impacts operating system security.
Checks: C-4559r88497_chk

Verify the operating system does not allow a non-certificate trusted host SSH logon to the system. Check for the value of the "HostbasedAuthentication" keyword with the following command: # grep -i hostbasedauthentication /etc/ssh/sshd_config HostbasedAuthentication no If the "HostbasedAuthentication" keyword is not set to "no", is missing, or is commented out, this is a finding.

Fix: F-4559r88498_fix

Configure the operating system to not allow a non-certificate trusted host SSH logon to the system. Edit the "/etc/ssh/sshd_config" file to uncomment or add the line for "HostbasedAuthentication" keyword and set the value to "no": HostbasedAuthentication no The SSH service must be restarted for changes to take effect.

b
The Red Hat Enterprise Linux operating system must require authentication upon booting into single-user and maintenance modes.
AC-3 - Medium - CCI-000213 - V-204437 - SV-204437r603261_rule
RMF Control
AC-3
Severity
Medium
CCI
CCI-000213
Version
RHEL-07-010481
Vuln IDs
  • V-204437
  • V-77823
Rule IDs
  • SV-204437r603261_rule
  • SV-92519
If the system does not require valid root 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.
Checks: C-4561r88503_chk

Verify the operating system must require authentication upon booting into single-user and maintenance modes. Check that the operating system requires authentication upon booting into single-user mode with the following command: # grep -i execstart /usr/lib/systemd/system/rescue.service | grep -i sulogin ExecStart=-/bin/sh -c "/usr/sbin/sulogin; /usr/bin/systemctl --fail --no-block default" If "ExecStart" does not have "/usr/sbin/sulogin" as an option, this is a finding.

Fix: F-4561r88504_fix

Configure the operating system to require authentication upon booting into single-user and maintenance modes. Add or modify the "ExecStart" line in "/usr/lib/systemd/system/rescue.service" to include "/usr/sbin/sulogin": ExecStart=-/bin/sh -c "/usr/sbin/sulogin; /usr/bin/systemctl --fail --no-block default"

c
Red Hat Enterprise Linux operating systems version 7.2 or newer with a Basic Input/Output System (BIOS) must require authentication upon booting into single-user and maintenance modes.
AC-3 - High - CCI-000213 - V-204438 - SV-204438r744095_rule
RMF Control
AC-3
Severity
High
CCI
CCI-000213
Version
RHEL-07-010482
Vuln IDs
  • V-204438
  • V-81005
Rule IDs
  • SV-204438r744095_rule
  • SV-95717
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 RHEL 7 and is designed to require a password to boot into single-user mode or make modifications to the boot menu.
Checks: C-4562r744093_chk

For systems that use UEFI, this is Not Applicable. For systems that are running a version of RHEL prior to 7.2, this is Not Applicable. Check to see if an encrypted grub superusers password is set. On systems that use a BIOS, use the following command: $ sudo grep -iw grub2_password /boot/grub2/user.cfg GRUB2_PASSWORD=grub.pbkdf2.sha512.[password_hash] If the grub superusers password does not begin with "grub.pbkdf2.sha512", this is a finding.

Fix: F-4562r744094_fix

Configure the system to encrypt the boot 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:

c
Red Hat Enterprise Linux operating systems version 7.2 or newer using Unified Extensible Firmware Interface (UEFI) must require authentication upon booting into single-user and maintenance modes.
AC-3 - High - CCI-000213 - V-204440 - SV-204440r744098_rule
RMF Control
AC-3
Severity
High
CCI
CCI-000213
Version
RHEL-07-010491
Vuln IDs
  • V-204440
  • V-81007
Rule IDs
  • SV-204440r744098_rule
  • SV-95719
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 RHEL 7 and is designed to require a password to boot into single-user mode or make modifications to the boot menu.
Checks: C-4564r744096_chk

For systems that use BIOS, this is Not Applicable. For systems that are running a version of RHEL prior to 7.2, this is Not Applicable. Check to see if an encrypted grub superusers password is set. On systems that use UEFI, use the following command: $ sudo grep -iw grub2_password /boot/efi/EFI/redhat/user.cfg GRUB2_PASSWORD=grub.pbkdf2.sha512.[password_hash] If the grub superusers password does not begin with "grub.pbkdf2.sha512", this is a finding.

Fix: F-4564r744097_fix

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

b
The Red Hat Enterprise Linux operating system must uniquely identify and must authenticate organizational users (or processes acting on behalf of organizational users) using multifactor authentication.
IA-2 - Medium - CCI-000766 - V-204441 - SV-204441r818813_rule
RMF Control
IA-2
Severity
Medium
CCI
CCI-000766
Version
RHEL-07-010500
Vuln IDs
  • V-204441
  • V-71965
Rule IDs
  • SV-204441r818813_rule
  • SV-86589
To assure accountability and prevent unauthenticated access, organizational users must be identified and authenticated to prevent potential misuse and compromise of the system. Organizational users include organizational employees or individuals the organization deems to have equivalent status of employees (e.g., contractors). Organizational 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-000104-GPOS-00051, SRG-OS-000106-GPOS-00053, SRG-OS-000107-GPOS-00054, SRG-OS-000109-GPOS-00056, SRG-OS-000108-GPOS-00055, SRG-OS-000108-GPOS-00057, SRG-OS-000108-GPOS-00058
Checks: C-4565r818812_chk

Verify the operating system requires multifactor authentication to uniquely identify organizational users using multifactor authentication. Check to see if smartcard authentication is enforced on the system: # authconfig --test | grep "pam_pkcs11 is enabled" If no results are returned, this is a finding. # authconfig --test | grep "smartcard removal action" If "smartcard removal action" is blank, this is a finding. # authconfig --test | grep "smartcard module" If any of the above checks are not configured, ask the administrator to indicate the AO-approved multifactor authentication in use and the configuration to support it. If there is no evidence of multifactor authentication, this is a finding.

Fix: F-4565r88516_fix

Configure the operating system to require individuals to be authenticated with a multifactor authenticator. Enable smartcard logons with the following commands: # authconfig --enablesmartcard --smartcardaction=0 --update # authconfig --enablerequiresmartcard -update Modify the "/etc/pam_pkcs11/pkcs11_eventmgr.conf" file to uncomment the following line: #/usr/X11R6/bin/xscreensaver-command -lock Modify the "/etc/pam_pkcs11/pam_pkcs11.conf" file to use the cackey module if required.

c
The Red Hat Enterprise Linux operating system must not have the rsh-server package installed.
CM-7 - High - CCI-000381 - V-204442 - SV-204442r603261_rule
RMF Control
CM-7
Severity
High
CCI
CCI-000381
Version
RHEL-07-020000
Vuln IDs
  • V-204442
  • V-71967
Rule IDs
  • SV-204442r603261_rule
  • SV-86591
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Operating systems are capable of providing a wide variety of functions and services. Some of the functions and services, provided by default, may not be necessary to support essential organizational operations (e.g., key missions, functions). The rsh-server service provides an unencrypted remote access service that does not provide for the confidentiality and integrity of user passwords or the remote session and has very weak authentication. If a privileged user were to log on using this service, the privileged user password could be compromised.
Checks: C-4566r88518_chk

Check to see if the rsh-server package is installed with the following command: # yum list installed rsh-server If the rsh-server package is installed, this is a finding.

Fix: F-4566r88519_fix

Configure the operating system to disable non-essential capabilities by removing the rsh-server package from the system with the following command: # yum remove rsh-server

c
The Red Hat Enterprise Linux operating system must not have the ypserv package installed.
CM-7 - High - CCI-000381 - V-204443 - SV-204443r603261_rule
RMF Control
CM-7
Severity
High
CCI
CCI-000381
Version
RHEL-07-020010
Vuln IDs
  • V-204443
  • V-71969
Rule IDs
  • SV-204443r603261_rule
  • SV-86593
Removing the "ypserv" package decreases the risk of the accidental (or intentional) activation of NIS or NIS+ services.
Checks: C-4567r88521_chk

The NIS service provides an unencrypted authentication service that does not provide for the confidentiality and integrity of user passwords or the remote session. Check to see if the "ypserve" package is installed with the following command: # yum list installed ypserv If the "ypserv" package is installed, this is a finding.

Fix: F-4567r88522_fix

Configure the operating system to disable non-essential capabilities by removing the "ypserv" package from the system with the following command: # yum remove ypserv

b
The Red Hat Enterprise Linux operating system must prevent nonprivileged users from executing privileged functions to include disabling, circumventing, or altering implemented security safeguards/countermeasures.
AC-3 - Medium - CCI-002165 - V-204444 - SV-204444r928571_rule
RMF Control
AC-3
Severity
Medium
CCI
CCI-002165
Version
RHEL-07-020020
Vuln IDs
  • V-204444
  • V-71971
Rule IDs
  • SV-204444r928571_rule
  • SV-86595
Preventing nonprivileged users from executing privileged functions mitigates the risk that unauthorized individuals or processes may gain unnecessary access to information or privileges. Privileged functions include, for example, establishing accounts, performing system integrity checks, or administering cryptographic key management activities. Nonprivileged users are individuals who do not possess appropriate authorizations. Circumventing intrusion detection and prevention mechanisms or malicious code protection mechanisms are examples of privileged functions that require protection from nonprivileged users.
Checks: C-4568r928569_chk

Verify the operating system prevents non-privileged users from executing privileged functions to include disabling, circumventing, or altering implemented security safeguards/countermeasures. Get a list of authorized users for the system. Check the list against the system by using the following command: $ sudo semanage login -l | more Login Name SELinux User MLS/MCS Range Service __default__ user_u s0-s0:c0.c1023 * root unconfined_u s0-s0:c0.c1023 * system_u system_u s0-s0:c0.c1023 * joe staff_u s0-s0:c0.c1023 * All administrators must be mapped to the , "staff_u", or an appropriately tailored confined SELinux user as defined by the organization. All authorized non-administrative users must be mapped to the "user_u" SELinux user. If they are not mapped in this way, this is a finding. If administrator accounts are mapped to the "sysadm_u" SELinux user and are not documented as an operational requirement with the ISSO, this is a finding. If administrator accounts are mapped to the "sysadm_u" SELinux user and are documented as an operational requirement with the ISSO, this can be downgraded to a CAT III.

Fix: F-4568r928570_fix

Configure the operating system to prevent non-privileged users from executing privileged functions to include disabling, circumventing, or altering implemented security safeguards/countermeasures. Use the following command to map a new user to the "staff_u" SELinux user: $ sudo semanage login -a -s staff_u <username> Use the following command to map an existing user to the "staff_u" SELinux user: $ sudo semanage login -m -s staff_u <username> Use the following command to map a new user to the "user_u" SELinux user: $ sudo semanage login -a -s user_u <username> Use the following command to map an existing user to the "user_u" SELinux user: $ sudo semanage login -m -s user_u <username>

b
The Red Hat Enterprise Linux operating system must be configured so that a file integrity tool verifies the baseline operating system configuration at least weekly.
CM-3 - Medium - CCI-001744 - V-204445 - SV-204445r902698_rule
RMF Control
CM-3
Severity
Medium
CCI
CCI-001744
Version
RHEL-07-020030
Vuln IDs
  • V-204445
  • V-71973
Rule IDs
  • SV-204445r902698_rule
  • SV-86597
Unauthorized changes to the baseline configuration could make the system vulnerable to various attacks or allow unauthorized access to the operating system. Changes to operating system configurations can have unintended side effects, some of which may be relevant to security. Detecting such changes and providing an automated response can help avoid unintended, negative consequences that could ultimately affect the security state of the operating system. The operating system's Information System Security Manager (ISSM)/Information System Security Officer (ISSO) and System Administrators (SAs) must be notified via email and/or monitoring system trap when there is an unauthorized modification of a configuration item.
Checks: C-36341r880846_chk

Verify the operating system routinely checks the baseline configuration for unauthorized changes. Note: A file integrity tool other than Advanced Intrusion Detection Environment (AIDE) may be used, but the tool must be executed at least once per week. Check for the presence of a cron job running daily or weekly on the system that executes AIDE daily to scan for changes to the system baseline. The command used in the example will use a daily occurrence. Check the cron directories for a script file controlling the execution of the file integrity application. For example, if AIDE is installed on the system, use the following command: # ls -al /etc/cron.* | grep aide -rwxr-xr-x 1 root root 602 Mar 6 20:02 aide # grep aide /etc/crontab /var/spool/cron/root /etc/crontab: 30 04 * * * root /usr/sbin/aide --check /var/spool/cron/root: 30 04 * * * /usr/sbin/aide --check If the file integrity application does not exist, or a script file controlling the execution of the file integrity application does not exist, this is a finding.

Fix: F-36304r902697_fix

Configure the file integrity tool to run automatically on the system at least weekly. The following example output is generic. It will set cron to run AIDE daily, but other file integrity tools may be used: # more /etc/cron.daily/aide #!/bin/bash /usr/sbin/aide --check | /bin/mail -s "$HOSTNAME - Daily AIDE integrity check run" root@example_server_name.mil Note: Per requirement RHEL-07-020028, the "mailx" package must be installed on the system to enable email functionality.

b
The Red Hat Enterprise Linux operating system must be configured so that designated personnel are notified if baseline configurations are changed in an unauthorized manner.
CM-3 - Medium - CCI-001744 - V-204446 - SV-204446r902701_rule
RMF Control
CM-3
Severity
Medium
CCI
CCI-001744
Version
RHEL-07-020040
Vuln IDs
  • V-204446
  • V-71975
Rule IDs
  • SV-204446r902701_rule
  • SV-86599
Unauthorized changes to the baseline configuration could make the system vulnerable to various attacks or allow unauthorized access to the operating system. Changes to operating system configurations can have unintended side effects, some of which may be relevant to security. Detecting such changes and providing an automated response can help avoid unintended, negative consequences that could ultimately affect the security state of the operating system. The operating system's Information System Security Manager (ISSM)/Information System Security Officer (ISSO) and System Administrators (SAs) must be notified via email and/or monitoring system trap when there is an unauthorized modification of a configuration item.
Checks: C-36342r902699_chk

Verify the operating system notifies designated personnel if baseline configurations are changed in an unauthorized manner. Note: A file integrity tool other than Advanced Intrusion Detection Environment (AIDE) may be used, but the tool must be executed and notify specified individuals via email or an alert. Check for the presence of a cron job running routinely on the system that executes AIDE to scan for changes to the system baseline. The commands used in the example will use a daily occurrence. Check the cron directories for a "crontab" script file controlling the execution of the file integrity application. For example, if AIDE is installed on the system, use the following command: # ls -al /etc/cron.* | grep aide -rwxr-xr-x 1 root root 602 Mar 6 20:02 aide # grep aide /etc/crontab /var/spool/cron/root /etc/crontab: 30 04 * * * root /usr/sbin/aide --check /var/spool/cron/root: 30 04 * * * /usr/sbin/aide --check AIDE does not have a configuration that will send a notification, so the cron job uses the mail application on the system to email the results of the file integrity run as in the following example: # more /etc/cron.daily/aide #!/bin/bash /usr/sbin/aide --check | /bin/mail -s "$HOSTNAME - Daily AIDE integrity check run" root@example_server_name.mil If the file integrity application does not notify designated personnel of changes, this is a finding.

Fix: F-36305r902700_fix

Configure the operating system to notify designated personnel if baseline configurations are changed in an unauthorized manner. The AIDE tool can be configured to email designated personnel with the use of the cron system. The following example output is generic. It will set cron to run AIDE daily and to send email at the completion of the analysis. # more /etc/cron.daily/aide /usr/sbin/aide --check | /bin/mail -s "$HOSTNAME - Daily AIDE integrity check run" root@example_server_name.mil Note: Per requirement RHEL-07-020028, the "mailx" package must be installed on the system to enable email functionality.

c
The Red Hat Enterprise Linux operating system must prevent the installation of software, patches, service packs, device drivers, or operating system components from a repository without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization.
CM-5 - High - CCI-001749 - V-204447 - SV-204447r877463_rule
RMF Control
CM-5
Severity
High
CCI
CCI-001749
Version
RHEL-07-020050
Vuln IDs
  • V-204447
  • V-71977
Rule IDs
  • SV-204447r877463_rule
  • SV-86601
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 CA.
Checks: C-4571r88533_chk

Verify the operating system prevents the installation of patches, service packs, device drivers, or operating system components from a repository without verification that they have been digitally signed using a certificate that is recognized and approved by the organization. Check that yum verifies the signature of packages from a repository prior to install with the following command: # grep gpgcheck /etc/yum.conf gpgcheck=1 If "gpgcheck" is not set to "1", or if options are missing or commented out, ask the System Administrator how the certificates for patches and other operating system components are verified. If there is no process to validate certificates that is approved by the organization, this is a finding.

Fix: F-4571r88534_fix

Configure the operating system to verify the signature of packages from a repository prior to install by setting the following option in the "/etc/yum.conf" file: gpgcheck=1

c
The Red Hat Enterprise Linux operating system must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization.
CM-5 - High - CCI-001749 - V-204448 - SV-204448r877463_rule
RMF Control
CM-5
Severity
High
CCI
CCI-001749
Version
RHEL-07-020060
Vuln IDs
  • V-204448
  • V-71979
Rule IDs
  • SV-204448r877463_rule
  • SV-86603
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 CA.
Checks: C-4572r88536_chk

Verify the operating system prevents the installation of patches, service packs, device drivers, or operating system components of local packages without verification that they have been digitally signed using a certificate that is recognized and approved by the organization. Check that yum verifies the signature of local packages prior to install with the following command: # grep localpkg_gpgcheck /etc/yum.conf localpkg_gpgcheck=1 If "localpkg_gpgcheck" is not set to "1", or if options are missing or commented out, ask the System Administrator how the signatures of local packages and other operating system components are verified. If there is no process to validate the signatures of local packages that is approved by the organization, this is a finding.

Fix: F-4572r88537_fix

Configure the operating system to verify the signature of local packages prior to install by setting the following option in the "/etc/yum.conf" file: localpkg_gpgcheck=1

b
The Red Hat Enterprise Linux operating system must be configured to disable USB mass storage.
CM-6 - Medium - CCI-000366 - V-204449 - SV-204449r942894_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-020100
Vuln IDs
  • V-204449
  • V-71983
Rule IDs
  • SV-204449r942894_rule
  • SV-86607
USB mass storage permits easy introduction of unknown devices, thereby facilitating malicious activity. Satisfies: SRG-OS-000114-GPOS-00059, SRG-OS-000378-GPOS-00163, SRG-OS-000480-GPOS-00227
Checks: C-4573r942892_chk

Verify the operating system disables the ability to load the USB Storage kernel module. # grep -r usb-storage /etc/modprobe.d/* | grep -i "/bin/false" | grep -v "^#" install usb-storage /bin/false If the command does not return any output, or the line is commented out, and use of USB Storage is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding. Verify the operating system disables the ability to use USB mass storage devices. Check to see if USB mass storage is disabled with the following command: # grep usb-storage /etc/modprobe.d/* | grep -i "blacklist" | grep -v "^#" blacklist usb-storage If the command does not return any output or the output is not "blacklist usb-storage", and use of USB storage devices is not documented with the ISSO as an operational requirement, this is a finding.

Fix: F-4573r942893_fix

Configure the operating system to disable the ability to use the USB Storage kernel module. Create a file under "/etc/modprobe.d" with the following command: # touch /etc/modprobe.d/usb-storage.conf Add the following line to the created file: install usb-storage /bin/false Configure the operating system to disable the ability to use USB mass storage devices. # vi /etc/modprobe.d/blacklist.conf Add or update the line: blacklist usb-storage

b
The Red Hat Enterprise Linux operating system must be configured so that the Datagram Congestion Control Protocol (DCCP) kernel module is disabled unless required.
IA-3 - Medium - CCI-001958 - V-204450 - SV-204450r942897_rule
RMF Control
IA-3
Severity
Medium
CCI
CCI-001958
Version
RHEL-07-020101
Vuln IDs
  • V-204450
  • V-77821
Rule IDs
  • SV-204450r942897_rule
  • SV-92517
Disabling DCCP protects the system against exploitation of any flaws in the protocol implementation.
Checks: C-4574r942895_chk

Verify the operating system disables the ability to load the DCCP kernel module. # grep -r dccp /etc/modprobe.d/* | grep -i "/bin/false" | grep -v "^#" install dccp /bin/false If the command does not return any output, or the line is commented out, and use of DCCP is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding. Verify the operating system disables the ability to use the DCCP kernel module. Check to see if the DCCP kernel module is disabled with the following command: # grep -i dccp /etc/modprobe.d/* | grep -i "blacklist" | grep -v "^#" blacklist dccp If the command does not return any output or the output is not "blacklist dccp", and use of the dccp kernel module is not documented with the ISSO as an operational requirement, this is a finding.

Fix: F-4574r942896_fix

Configure the operating system to disable the ability to use the DCCP kernel module. Create a file under "/etc/modprobe.d" with the following command: # touch /etc/modprobe.d/dccp.conf Add the following line to the created file: install dccp /bin/false Ensure that the DCCP module is blacklisted: # vi /etc/modprobe.d/blacklist.conf Add or update the line: blacklist dccp

b
The Red Hat Enterprise Linux operating system must disable the file system automounter unless required.
CM-6 - Medium - CCI-000366 - V-204451 - SV-204451r853893_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-020110
Vuln IDs
  • V-204451
  • V-71985
Rule IDs
  • SV-204451r853893_rule
  • SV-86609
Automatically mounting file systems permits easy introduction of unknown devices, thereby facilitating malicious activity. Satisfies: SRG-OS-000114-GPOS-00059, SRG-OS-000378-GPOS-00163, SRG-OS-000480-GPOS-00227
Checks: C-4575r88545_chk

Verify the operating system disables the ability to automount devices. Check to see if automounter service is active with the following command: # 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-4575r88546_fix

Configure the operating system to disable the ability to automount devices. Turn off the automount service with the following commands: # systemctl stop autofs # systemctl disable autofs If "autofs" is required for Network File System (NFS), it must be documented with the ISSO.

a
The Red Hat Enterprise Linux operating system must remove all software components after updated versions have been installed.
SI-2 - Low - CCI-002617 - V-204452 - SV-204452r853894_rule
RMF Control
SI-2
Severity
Low
CCI
CCI-002617
Version
RHEL-07-020200
Vuln IDs
  • V-204452
  • V-71987
Rule IDs
  • SV-204452r853894_rule
  • SV-86611
Previous versions of software components that are not removed from the information system after updates have been installed may be exploited by adversaries. Some information technology products may remove older versions of software automatically from the information system.
Checks: C-4576r88548_chk

Verify the operating system removes all software components after updated versions have been installed. Check if yum is configured to remove unneeded packages with the following command: # grep -i clean_requirements_on_remove /etc/yum.conf clean_requirements_on_remove=1 If "clean_requirements_on_remove" is not set to "1", "True", or "yes", or is not set in "/etc/yum.conf", this is a finding.

Fix: F-4576r88549_fix

Configure the operating system to remove all software components after updated versions have been installed. Set the "clean_requirements_on_remove" option to "1" in the "/etc/yum.conf" file: clean_requirements_on_remove=1

b
The Red Hat Enterprise Linux operating system must enable SELinux.
AC-3 - Medium - CCI-002165 - V-204453 - SV-204453r942900_rule
RMF Control
AC-3
Severity
Medium
CCI
CCI-002165
Version
RHEL-07-020210
Vuln IDs
  • V-204453
  • V-71989
Rule IDs
  • SV-204453r942900_rule
  • SV-86613
Without verification of the security functions, security functions may not operate correctly and the failure may go unnoticed. Security function is defined as the hardware, software, and/or firmware of the information system responsible for enforcing the system security policy and supporting the isolation of code and data on which the protection is based. Security functionality includes, but is not limited to, establishing system accounts, configuring access authorizations (i.e., permissions, privileges), setting events to be audited, and setting intrusion detection parameters. This requirement applies to operating systems performing security function verification/testing and/or systems and environments that require this functionality.
Checks: C-36343r942898_chk

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

Fix: F-36306r942899_fix

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

b
The Red Hat Enterprise Linux operating system must enable the SELinux targeted policy.
AC-3 - Medium - CCI-002165 - V-204454 - SV-204454r942903_rule
RMF Control
AC-3
Severity
Medium
CCI
CCI-002165
Version
RHEL-07-020220
Vuln IDs
  • V-204454
  • V-71991
Rule IDs
  • SV-204454r942903_rule
  • SV-86615
Without verification of the security functions, security functions may not operate correctly and the failure may go unnoticed. Security function is defined as the hardware, software, and/or firmware of the information system responsible for enforcing the system security policy and supporting the isolation of code and data on which the protection is based. Security functionality includes, but is not limited to, establishing system accounts, configuring access authorizations (i.e., permissions, privileges), setting events to be audited, and setting intrusion detection parameters. This requirement applies to operating systems performing security function verification/testing and/or systems and environments that require this functionality.
Checks: C-36344r942901_chk

Verify the operating system verifies correct operation of all security functions. Check if "SELinux" is active and is enforcing the targeted policy with the following command: # sestatus SELinux status: enabled SELinuxfs mount: /selinux SELinux root directory: /etc/selinux Loaded policy name: targeted Current mode: enforcing Mode from config file: enforcing Policy MLS status: enabled Policy deny_unknown status: allowed Max kernel policy version: 28 If the "Loaded policy name" is not set to "targeted", this is a finding. Verify that the /etc/selinux/config file is configured to the "SELINUXTYPE" to "targeted": # grep -i "selinuxtype" /etc/selinux/config | grep -v '^#' SELINUXTYPE = targeted If no results are returned or "SELINUXTYPE" is not set to "targeted", this is a finding.

Fix: F-36307r942902_fix

Configure the operating system 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
The Red Hat Enterprise Linux operating system must be configured so that the x86 Ctrl-Alt-Delete key sequence is disabled on the command line.
CM-6 - High - CCI-000366 - V-204455 - SV-204455r928574_rule
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
RHEL-07-020230
Vuln IDs
  • V-204455
  • V-71993
Rule IDs
  • SV-204455r928574_rule
  • SV-86617
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 the GNOME graphical environment, risk of unintentional reboot from the Ctrl-Alt-Delete sequence is reduced because the user will be prompted before any action is taken.
Checks: C-4579r928572_chk

Verify the operating system is not configured to reboot the system when Ctrl-Alt-Delete is pressed. Check that the ctrl-alt-del.target is masked and not active with the following command: # systemctl status ctrl-alt-del.target ctrl-alt-del.target Loaded: masked (/dev/null; bad) Active: inactive (dead) If the ctrl-alt-del.target is not masked, this is a finding. If the ctrl-alt-del.target is active, this is a finding.

Fix: F-4579r928573_fix

Configure the system to disable the Ctrl-Alt-Delete sequence for the command line with the following commands: # systemctl disable ctrl-alt-del.target # systemctl mask ctrl-alt-del.target

c
The Red Hat Enterprise Linux operating system must be configured so that the x86 Ctrl-Alt-Delete key sequence is disabled in the Graphical User Interface.
CM-6 - High - CCI-000366 - V-204456 - SV-204456r603261_rule
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
RHEL-07-020231
Vuln IDs
  • V-204456
  • V-94843
Rule IDs
  • SV-204456r603261_rule
  • SV-104673
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 the graphical environment, risk of unintentional reboot from the Ctrl-Alt-Delete sequence is reduced because the user will be prompted before any action is taken.
Checks: C-4580r590040_chk

Note: If the operating system does not have a graphical user interface installed, this requirement is Not Applicable. Verify the operating system is not configured to reboot the system when Ctrl-Alt-Delete is pressed. Check that the ctrl-alt-del.target is masked and not active in the graphical user interface with the following command: # grep logout /etc/dconf/db/local.d/* logout='' If "logout" is not set to use two single quotations, or is missing, this is a finding.

Fix: F-4580r590041_fix

Configure the system to disable the Ctrl-Alt-Delete sequence for the graphical user interface with the following command: # touch /etc/dconf/db/local.d/00-disable-CAD Add the setting to disable the Ctrl-Alt-Delete sequence for the graphical user interface: [org/gnome/settings-daemon/plugins/media-keys] logout=''

b
The Red Hat Enterprise Linux operating system must define default permissions for all authenticated users in such a way that the user can only read and modify their own files.
CM-6 - Medium - CCI-000366 - V-204457 - SV-204457r603261_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-020240
Vuln IDs
  • V-204457
  • V-71995
Rule IDs
  • SV-204457r603261_rule
  • SV-86619
Setting the most restrictive default permissions ensures that when new accounts are created, they do not have unnecessary access.
Checks: C-4581r88563_chk

Verify the operating system defines default permissions for all authenticated users in such a way that the user can only read and modify their own files. Check for the value of the "UMASK" parameter in "/etc/login.defs" file with the following command: Note: If the value of the "UMASK" parameter is set to "000" in "/etc/login.defs" file, the Severity is raised to a CAT I. # grep -i umask /etc/login.defs UMASK 077 If the value for the "UMASK" parameter is not "077", or the "UMASK" parameter is missing or is commented out, this is a finding.

Fix: F-4581r88564_fix

Configure the operating system to define default permissions for all authenticated users in such a way that the user can only read and modify their own files. Add or edit the line for the "UMASK" parameter in "/etc/login.defs" file to "077": UMASK 077

c
The Red Hat Enterprise Linux operating system must be a vendor supported release.
CM-6 - High - CCI-000366 - V-204458 - SV-204458r744100_rule
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
RHEL-07-020250
Vuln IDs
  • V-204458
  • V-71997
Rule IDs
  • SV-204458r744100_rule
  • SV-86621
An operating system release is considered "supported" if the vendor continues to provide security patches for the product. With an unsupported release, it will not be possible to resolve security issues discovered in the system software. Red Hat offers the Extended Update Support (EUS) Add-On to a Red Hat Enterprise Linux subscription, for a fee, for those customers who wish to standardize on a specific minor release for an extended period. RHEL 7.7 marks the final minor release that EUS will be available, while 7.9 is the final minor release overall.
Checks: C-4582r744099_chk

Verify the version of the operating system is vendor supported. Check the version of the operating system with the following command: # cat /etc/redhat-release Red Hat Enterprise Linux Server release 7.9 (Maipo) Current End of Extended Update Support for RHEL 7.6 is 31 May 2021. Current End of Extended Update Support for RHEL 7.7 is 30 August 2021. Current End of Maintenance Support for RHEL 7.9 is 30 June 2024. If the release is not supported by the vendor, this is a finding.

Fix: F-4582r462547_fix

Upgrade to a supported version of the operating system.

b
The Red Hat Enterprise Linux operating system security patches and updates must be installed and up to date.
CM-6 - Medium - CCI-000366 - V-204459 - SV-204459r603261_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-020260
Vuln IDs
  • V-204459
  • V-71999
Rule IDs
  • SV-204459r603261_rule
  • SV-86623
Timely patching is critical for maintaining the operational availability, confidentiality, and integrity of information technology (IT) systems. However, failure to keep operating system and application software patched is a common mistake made by IT professionals. New patches are released daily, and it is often difficult for even experienced System Administrators to keep abreast of all the new patches. When new weaknesses in an operating system exist, patches are usually made available by the vendor to resolve the problems. If the most recent security patches and updates are not installed, unauthorized users may take advantage of weaknesses in the unpatched software. The lack of prompt attention to patching could result in a system compromise.
Checks: C-4583r88569_chk

Verify the operating system security patches and updates are installed and up to date. Updates are required to be applied with a frequency determined by the site or Program Management Office (PMO). Obtain the list of available package security updates from Red Hat. The URL for updates is https://rhn.redhat.com/errata/. It is important to note that updates provided by Red Hat may not be present on the system if the underlying packages are not installed. Check that the available package security updates have been installed on the system with the following command: # yum history list | more Loaded plugins: langpacks, product-id, subscription-manager ID | Command line | Date and time | Action(s) | Altered ------------------------------------------------------------------------------- 70 | install aide | 2016-05-05 10:58 | Install | 1 69 | update -y | 2016-05-04 14:34 | Update | 18 EE 68 | install vlc | 2016-04-21 17:12 | Install | 21 67 | update -y | 2016-04-21 17:04 | Update | 7 EE 66 | update -y | 2016-04-15 16:47 | E, I, U | 84 EE If package updates have not been performed on the system within the timeframe that the site/program documentation requires, this is a finding. Typical update frequency may be overridden by Information Assurance Vulnerability Alert (IAVA) notifications from CYBERCOM. If the operating system is in non-compliance with the Information Assurance Vulnerability Management (IAVM) process, this is a finding.

Fix: F-4583r88570_fix

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

b
The Red Hat Enterprise Linux operating system must not have unnecessary accounts.
CM-6 - Medium - CCI-000366 - V-204460 - SV-204460r603261_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-020270
Vuln IDs
  • V-204460
  • V-72001
Rule IDs
  • SV-204460r603261_rule
  • SV-86625
Accounts providing no operational purpose provide additional opportunities for system compromise. Unnecessary accounts include user accounts for individuals not requiring access to the system and application accounts for applications not installed on the system.
Checks: C-4584r88572_chk

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

Fix: F-4584r88573_fix

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

a
The Red Hat Enterprise Linux operating system must be configured so that all Group Identifiers (GIDs) referenced in the /etc/passwd file are defined in the /etc/group file.
IA-2 - Low - CCI-000764 - V-204461 - SV-204461r603261_rule
RMF Control
IA-2
Severity
Low
CCI
CCI-000764
Version
RHEL-07-020300
Vuln IDs
  • V-204461
  • V-72003
Rule IDs
  • SV-204461r603261_rule
  • SV-86627
If a user is assigned the GID of a group not existing on the system, and a group with the GID is subsequently created, the user may have unintended rights to any files associated with the group.
Checks: C-4585r88575_chk

Verify all GIDs referenced in the "/etc/passwd" file are defined in the "/etc/group" file. Check that all referenced GIDs exist with the following command: # pwck -r If GIDs referenced in "/etc/passwd" file are returned as not defined in "/etc/group" file, this is a finding.

Fix: F-4585r88576_fix

Configure the system to define all GIDs found in the "/etc/passwd" file by modifying the "/etc/group" file to add any non-existent group referenced in the "/etc/passwd" file, or change the GIDs referenced in the "/etc/passwd" file to a group that exists in "/etc/group".

c
The Red Hat Enterprise Linux operating system must be configured so that the root account must be the only account having unrestricted access to the system.
CM-6 - High - CCI-000366 - V-204462 - SV-204462r603261_rule
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
RHEL-07-020310
Vuln IDs
  • V-204462
  • V-72005
Rule IDs
  • SV-204462r603261_rule
  • SV-86629
If an account other than root also has a User Identifier (UID) of "0", it has root authority, giving that account unrestricted access to the entire operating system. Multiple accounts with a UID of "0" afford an opportunity for potential intruders to guess a password for a privileged account.
Checks: C-4586r88578_chk

Check the system for duplicate UID "0" assignments with the following command: # awk -F: '$3 == 0 {print $1}' /etc/passwd If any accounts other than root have a UID of "0", this is a finding.

Fix: F-4586r88579_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, the UID should be changed to one greater than "0" but less than "1000". Otherwise, assign a UID of greater than "1000" that has not already been assigned.

b
The Red Hat Enterprise Linux operating system must be configured so that all files and directories have a valid owner.
AC-3 - Medium - CCI-002165 - V-204463 - SV-204463r853897_rule
RMF Control
AC-3
Severity
Medium
CCI
CCI-002165
Version
RHEL-07-020320
Vuln IDs
  • V-204463
  • V-72007
Rule IDs
  • SV-204463r853897_rule
  • SV-86631
Unowned files and directories may be unintentionally inherited if a user is assigned the same User Identifier "UID" as the UID of the un-owned files.
Checks: C-4587r88581_chk

Verify all files and directories on the system have a valid owner. Check the owner of all files and directories with the following command: Note: The value after -fstype must be replaced with the filesystem type. XFS is used as an example. # find / -fstype xfs -nouser If any files on the system do not have an assigned owner, this is a finding.

Fix: F-4587r88582_fix

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

b
The Red Hat Enterprise Linux operating system must be configured so that all files and directories have a valid group owner.
AC-3 - Medium - CCI-002165 - V-204464 - SV-204464r853898_rule
RMF Control
AC-3
Severity
Medium
CCI
CCI-002165
Version
RHEL-07-020330
Vuln IDs
  • V-204464
  • V-72009
Rule IDs
  • SV-204464r853898_rule
  • SV-86633
Files without a valid group owner may be unintentionally inherited if a group is assigned the same Group Identifier (GID) as the GID of the files without a valid group owner.
Checks: C-4588r88584_chk

Verify all files and directories on the system have a valid group. Check the owner of all files and directories with the following command: Note: The value after -fstype must be replaced with the filesystem type. XFS is used as an example. # find / -fstype xfs -nogroup If any files on the system do not have an assigned group, this is a finding.

Fix: F-4588r88585_fix

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

b
The Red Hat Enterprise Linux operating system must be configured so that all local interactive user accounts, upon creation, are assigned a home directory.
CM-6 - Medium - CCI-000366 - V-204466 - SV-204466r603261_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-020610
Vuln IDs
  • V-204466
  • V-72013
Rule IDs
  • SV-204466r603261_rule
  • SV-86637
If local interactive users are not assigned a valid home directory, there is no place for the storage and control of files they should own.
Checks: C-4590r88590_chk

Verify all local interactive users on the system are assigned a home directory upon creation. Check to see if the system is configured to create home directories for local interactive users with the following command: # grep -i create_home /etc/login.defs CREATE_HOME yes If the value for "CREATE_HOME" parameter is not set to "yes", the line is missing, or the line is commented out, this is a finding.

Fix: F-4590r88591_fix

Configure the operating system 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
The Red Hat Enterprise Linux operating system must be configured so that all local interactive users have a home directory assigned and defined in the /etc/passwd file.
CM-6 - Medium - CCI-000366 - V-204467 - SV-204467r603826_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-020620
Vuln IDs
  • V-204467
  • V-72015
Rule IDs
  • SV-204467r603826_rule
  • SV-86639
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. In addition, if a local interactive user has a home directory defined that does not exist, the user may be given access to the / directory as the current working directory upon logon. This could create a Denial of Service because the user would not be able to access their logon configuration files, and it may give them visibility to system files they normally would not be able to access.
Checks: C-4591r622289_chk

Verify local interactive users on the system have a home directory assigned and the directory exists. Check the home directory assignment for all local interactive non-privileged users on the system with the following command: # awk -F: '($3&gt;=1000)&amp;&amp;($7 !~ /nologin/){print $1, $3, $6}' /etc/passwd smithj 1001 /home/smithj Note: This may miss interactive users that have been assigned a privileged UID. Evidence of interactive use may be obtained from a number of log files containing system logon information. Check that all referenced home directories exist with the following command: # pwck -r user 'smithj': directory '/home/smithj' does not exist If any home directories referenced in "/etc/passwd" are returned as not defined, or if any interactive users do not have a home directory assigned, this is a finding.

Fix: F-4591r462550_fix

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

b
The Red Hat Enterprise Linux operating system must be configured so that all local interactive user home directories have mode 0750 or less permissive.
CM-6 - Medium - CCI-000366 - V-204468 - SV-204468r603828_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-020630
Vuln IDs
  • V-204468
  • V-72017
Rule IDs
  • SV-204468r603828_rule
  • SV-86641
Excessive permissions on local interactive user home directories may allow unauthorized access to user files by other users.
Checks: C-4592r622291_chk

Verify the assigned home directory of all local interactive users has a mode of "0750" or less permissive. Check the home directory assignment for all non-privileged users on the system with the following command: Note: This may miss interactive users that have been assigned a privileged User Identifier (UID). Evidence of interactive use may be obtained from a number of log files containing system logon information. # ls -ld $(awk -F: '($3&gt;=1000)&amp;&amp;($7 !~ /nologin/){print $6}' /etc/passwd) -rwxr-x--- 1 smithj users 18 Mar 5 17:06 /home/smithj If home directories referenced in "/etc/passwd" do not have a mode of "0750" or less permissive, this is a finding.

Fix: F-4592r88597_fix

Change the mode of interactive user's home directories to "0750". To change the mode of a local interactive user's home directory, use the following command: Note: The example will be for the user "smithj". # chmod 0750 /home/smithj

b
The Red Hat Enterprise Linux operating system must be configured so that all local interactive user home directories are owned by their respective users.
CM-6 - Medium - CCI-000366 - V-204469 - SV-204469r603830_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-020640
Vuln IDs
  • V-204469
  • V-72019
Rule IDs
  • SV-204469r603830_rule
  • SV-86643
If a local interactive user does not own their home directory, unauthorized users could access or modify the user's files, and the users may not be able to access their own files.
Checks: C-4593r622293_chk

Verify the assigned home directory of all local interactive users on the system exists. Check the home directory assignment for all local interactive users on the system with the following command: # ls -ld $(awk -F: '($3&gt;=1000)&amp;&amp;($7 !~ /nologin/){print $6}' /etc/passwd) -rwxr-x--- 1 smithj users 18 Mar 5 17:06 /home/smithj If any home directories referenced in "/etc/passwd" are not owned by the interactive user, this is a finding.

Fix: F-4593r88600_fix

Change the owner of a local interactive user's home directories to that owner. To change the owner of a local interactive user's home directory, use the following command: Note: The example will be for the user smithj, who has a home directory of "/home/smithj". # chown smithj /home/smithj

b
The Red Hat Enterprise Linux operating system must be configured so that all local interactive user home directories are group-owned by the home directory owners primary group.
CM-6 - Medium - CCI-000366 - V-204470 - SV-204470r880764_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-020650
Vuln IDs
  • V-204470
  • V-72021
Rule IDs
  • SV-204470r880764_rule
  • SV-86645
If the Group Identifier (GID) of a local interactive user's home directory is not the same as the primary GID of the user, this would allow unauthorized access to the user's files, and users that share the same group may not be able to access files that they legitimately should.
Checks: C-4594r880762_chk

Verify the assigned home directory of all local interactive users is group-owned by that user's primary GID. Check the home directory assignment for all local interactive users on the system with the following command: # ls -ld $(awk -F: '($3&gt;=1000)&amp;&amp;($7 !~ /nologin/){print $6}' /etc/passwd) -rwxr-x--- 1 smithj users 13 Apr 1 04:20 /home/smithj Check the user's primary group with the following command: # grep $(grep smithj /etc/passwd | awk -F: '{print $4}') /etc/group users:x:250:smithj,marinc,chongt If the user home directory referenced in "/etc/passwd" is not group-owned by that user's primary GID, this is a finding.

Fix: F-4594r880763_fix

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

b
The Red Hat Enterprise Linux operating system must be configured so that all files and directories contained in local interactive user home directories have a valid owner.
CM-6 - Medium - CCI-000366 - V-204471 - SV-204471r744105_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-020660
Vuln IDs
  • V-204471
  • V-72023
Rule IDs
  • SV-204471r744105_rule
  • SV-86647
Unowned files and directories may be unintentionally inherited if a user is assigned the same User Identifier "UID" as the UID of the un-owned files.
Checks: C-4595r744103_chk

Verify all files and directories in a local interactive user's home directory have a valid owner. Check the owner of all files and directories in a local interactive user's home directory with the following command: Note: The example will be for the user "smithj", who has a home directory of "/home/smithj". $ sudo ls -lLR /home/smithj -rw-r--r-- 1 smithj smithj 18 Mar 5 17:06 file1 -rw-r--r-- 1 smithj smithj 193 Mar 5 17:06 file2 -rw-r--r-- 1 smithj smithj 231 Mar 5 17:06 file3 If any files or directories are found without an owner, this is a finding.

Fix: F-4595r744104_fix

Either remove all files and directories from the system that do not have a valid user, or assign a valid user to all unowned files and directories on RHEL 7 with the "chown" command: Note: The example will be for the user smithj, who has a home directory of "/home/smithj". $ sudo chown smithj /home/smithj/<file or directory>

b
The Red Hat Enterprise Linux operating system must be configured so that all files and directories contained in local interactive user home directories are group-owned by a group of which the home directory owner is a member.
CM-6 - Medium - CCI-000366 - V-204472 - SV-204472r603261_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-020670
Vuln IDs
  • V-204472
  • V-72025
Rule IDs
  • SV-204472r603261_rule
  • SV-86649
If a local interactive user's files are group-owned by a group of which the user is not a member, unintended users may be able to access them.
Checks: C-4596r88608_chk

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

Fix: F-4596r88609_fix

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

b
The Red Hat Enterprise Linux operating system must be configured so that all files and directories contained in local interactive user home directories have a mode of 0750 or less permissive.
CM-6 - Medium - CCI-000366 - V-204473 - SV-204473r603261_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-020680
Vuln IDs
  • V-204473
  • V-72027
Rule IDs
  • SV-204473r603261_rule
  • SV-86651
If a local interactive user files have excessive permissions, unintended users may be able to access or modify them.
Checks: C-4597r88611_chk

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

Fix: F-4597r88612_fix

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

b
The Red Hat Enterprise Linux operating system must be configured so that all local initialization files for interactive users are owned by the home directory user or root.
CM-6 - Medium - CCI-000366 - V-204474 - SV-204474r917821_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-020690
Vuln IDs
  • V-204474
  • V-72029
Rule IDs
  • SV-204474r917821_rule
  • SV-86653
Local initialization files are used to configure the user's shell environment upon logon. Malicious modification of these files could compromise accounts upon logon.
Checks: C-4598r917819_chk

Verify the local initialization files of all local interactive users are owned by that user. Check the home directory assignment for all nonprivileged users on the system with the following command: Note: The example will be for the smithj user, who has a home directory of "/home/smithj". # awk -F: '($3&gt;=1000)&amp;&amp;($7 !~ /nologin/){print $1, $3, $6}' /etc/passwd smithj 1000 /home/smithj Note: This may miss interactive users that have been assigned a privileged User Identifier (UID). Evidence of interactive use may be obtained from a number of log files containing system logon information. Check the owner of all local interactive users' initialization files with the following command: # ls -al /home/smithj/.[^.]* | more -rw-------. 1 smithj users 2984 Apr 27 19:02 .bash_history -rw-r--r--. 1 smithj users 18 Aug 21 2019 .bash_logout -rw-r--r--. 1 smithj users 193 Aug 21 2019 .bash_profile If all local interactive users' initialization files are not owned by that user or root, this is a finding.

Fix: F-4598r917820_fix

Set the owner of the local initialization files for interactive users to either the directory owner or root with the following command: Note: The example will be for the smithj user, who has a home directory of "/home/smithj". # chown smithj /home/smithj/.[^.]*

b
The Red Hat Enterprise Linux operating system must be configured so that all local initialization files for local interactive users are be group-owned by the users primary group or root.
CM-6 - Medium - CCI-000366 - V-204475 - SV-204475r917824_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-020700
Vuln IDs
  • V-204475
  • V-72031
Rule IDs
  • SV-204475r917824_rule
  • SV-86655
Local initialization files for interactive users are used to configure the user's shell environment upon logon. Malicious modification of these files could compromise accounts upon logon.
Checks: C-4599r917822_chk

Verify the local initialization files of all local interactive users are group-owned by that user's primary Group Identifier (GID). Check the home directory assignment for all nonprivileged users on the system with the following command: Note: The example will be for the smithj user, who has a home directory of "/home/smithj" and a primary group of "users". # awk -F: '($4&gt;=1000)&amp;&amp;($7 !~ /nologin/){print $1, $4, $6}' /etc/passwd smithj 1000 /home/smithj # grep 1000 /etc/group users:x:1000:smithj,jonesj,jacksons Note: This may miss interactive users that have been assigned a privileged User Identifier (UID). Evidence of interactive use may be obtained from a number of log files containing system logon information. Check the group owner of all local interactive users' initialization files with the following command: # ls -al /home/smithj/.[^.]* | more -rw-------. 1 smithj users 2984 Apr 27 19:02 .bash_history -rw-r--r--. 1 smithj users 18 Aug 21 2019 .bash_logout -rw-r--r--. 1 smithj users 193 Aug 21 2019 .bash_profile If all local interactive users' initialization files are not group-owned by that user's primary GID, this is a finding.

Fix: F-4599r917823_fix

Change the group owner of a local interactive user's files to the group found in "/etc/passwd" for the user. To change the group owner of a local interactive user's home directory, use the following command: Note: The example will be for the user smithj, who has a home directory of "/home/smithj" and has a primary group of users. # chgrp users /home/smithj/.[^.]*

b
The Red Hat Enterprise Linux operating system must be configured so that all local initialization files have mode 0740 or less permissive.
CM-6 - Medium - CCI-000366 - V-204476 - SV-204476r917827_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-020710
Vuln IDs
  • V-204476
  • V-72033
Rule IDs
  • SV-204476r917827_rule
  • SV-86657
Local initialization files are used to configure the user's shell environment upon logon. Malicious modification of these files could compromise accounts upon logon.
Checks: C-4600r917825_chk

Verify that all local initialization files have a mode of "0740" or less permissive. Check the mode on all local initialization files with the following command: Note: The example will be for the "smithj" user, who has a home directory of "/home/smithj". # ls -al /home/smithj/.[^.]* | more -rw-------. 1 smithj users 2984 Apr 27 19:02 .bash_history -rw-r--r--. 1 smithj users 18 Aug 21 2019 .bash_logout -rw-r--r--. 1 smithj users 193 Aug 21 2019 .bash_profile If any local initialization files have a mode more permissive than "0740", this is a finding.

Fix: F-4600r917826_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". # chmod 0740 /home/smithj/.[^.]*

b
The Red Hat Enterprise Linux operating system must be configured so that all local interactive user initialization files executable search paths contain only paths that resolve to the users home directory.
CM-6 - Medium - CCI-000366 - V-204477 - SV-204477r792828_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-020720
Vuln IDs
  • V-204477
  • V-72035
Rule IDs
  • SV-204477r792828_rule
  • SV-86659
The executable search path (typically the PATH environment variable) contains a list of directories for the shell to search to find executables. If this path includes the current working directory (other than the user's home directory), executables in these directories may be executed instead of system commands. This variable is formatted as a colon-separated list of directories. If there is an empty entry, such as a leading or trailing colon or two consecutive colons, this is interpreted as the current working directory. If deviations from the default system search path for the local interactive user are required, they must be documented with the Information System Security Officer (ISSO).
Checks: C-4601r792827_chk

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

Fix: F-4601r88624_fix

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

b
The Red Hat Enterprise Linux operating system must be configured so that local initialization files do not execute world-writable programs.
CM-6 - Medium - CCI-000366 - V-204478 - SV-204478r603261_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-020730
Vuln IDs
  • V-204478
  • V-72037
Rule IDs
  • SV-204478r603261_rule
  • SV-86661
If user start-up files execute world-writable programs, especially in unprotected directories, they could be maliciously modified to destroy user files or otherwise compromise the system at the user level. If the system is compromised at the user level, it is easier to elevate privileges to eventually compromise the system at the root and network level.
Checks: C-4602r88626_chk

Verify that local initialization files do not execute world-writable programs. Check the system for world-writable files with the following command: # find / -xdev -perm -002 -type f -exec ls -ld {} \; | more For all files listed, check for their presence in the local initialization files with the following commands: Note: The example will be for a system that is configured to create users' home directories in the "/home" directory. # grep &lt;file&gt; /home/*/.* If any local initialization files are found to reference world-writable files, this is a finding.

Fix: F-4602r88627_fix

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

b
The Red Hat Enterprise Linux operating system must be configured so that all system device files are correctly labeled to prevent unauthorized modification.
CM-3 - Medium - CCI-000318 - V-204479 - SV-204479r853899_rule
RMF Control
CM-3
Severity
Medium
CCI
CCI-000318
Version
RHEL-07-020900
Vuln IDs
  • V-204479
  • V-72039
Rule IDs
  • SV-204479r853899_rule
  • SV-86663
If an unauthorized or modified device is allowed to exist on the system, there is the possibility the system may perform unintended or unauthorized operations.
Checks: C-4603r88629_chk

Verify that all system device files are correctly labeled to prevent unauthorized modification. List all device files on the system that are incorrectly labeled with the following commands: Note: Device files are normally found under "/dev", but applications may place device files in other directories and may necessitate a search of the entire system. #find /dev -context *:device_t:* \( -type c -o -type b \) -printf "%p %Z\n" #find /dev -context *:unlabeled_t:* \( -type c -o -type b \) -printf "%p %Z\n" Note: There are device files, such as "/dev/vmci", that are used when the operating system is a host virtual machine. They will not be owned by a user on the system and require the "device_t" label to operate. These device files are not a finding. If there is output from either of these commands, other than already noted, this is a finding.

Fix: F-4603r88630_fix

Run the following command to determine which package owns the device file: # rpm -qf <filename> The package can be reinstalled from a yum repository using the command: # sudo yum reinstall <packagename> Alternatively, the package can be reinstalled from trusted media using the command: # sudo rpm -Uvh <packagename>

b
The Red Hat Enterprise Linux operating system must be configured so that file systems containing user home directories are mounted to prevent files with the setuid and setgid bit set from being executed.
CM-6 - Medium - CCI-000366 - V-204480 - SV-204480r603838_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-021000
Vuln IDs
  • V-204480
  • V-72041
Rule IDs
  • SV-204480r603838_rule
  • SV-86665
The "nosuid" mount option causes the system to not execute setuid and setgid files with owner privileges. This option must be used for mounting any file system not containing approved setuid and setguid files. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-4604r622301_chk

Verify file systems that contain user home directories are mounted with the "nosuid" option. Find the file system(s) that contain the user home directories with the following command: Note: If a separate file system has not been created for the user home directories (user home directories are mounted under "/"), this is not a finding as the "nosuid" option cannot be used on the "/" system. # awk -F: '($3&gt;=1000)&amp;&amp;($7 !~ /nologin/){print $1, $3, $6}' /etc/passwd smithj 1001 /home/smithj thomasr 1002 /home/thomasr Check the file systems that are mounted at boot time with the following command: # more /etc/fstab UUID=a411dc99-f2a1-4c87-9e05-184977be8539 /home ext4 rw,relatime,discard,data=ordered,nosuid 0 2 If a file system found in "/etc/fstab" refers to the user home directory file system and it does not have the "nosuid" option set, this is a finding.

Fix: F-4604r88633_fix

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

b
The Red Hat Enterprise Linux operating system must prevent files with the setuid and setgid bit set from being executed on file systems that are used with removable media.
CM-6 - Medium - CCI-000366 - V-204481 - SV-204481r603261_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-021010
Vuln IDs
  • V-204481
  • V-72043
Rule IDs
  • SV-204481r603261_rule
  • SV-86667
The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-4605r88635_chk

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

Fix: F-4605r88636_fix

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

b
The Red Hat Enterprise Linux operating system must prevent files with the setuid and setgid bit set from being executed on file systems that are being imported via Network File System (NFS).
CM-6 - Medium - CCI-000366 - V-204482 - SV-204482r603261_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-021020
Vuln IDs
  • V-204482
  • V-72045
Rule IDs
  • SV-204482r603261_rule
  • SV-86669
The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-4606r88638_chk

Verify file systems that are being NFS imported are configured with the "nosuid" option. Find the file system(s) that contain the directories being exported with the following command: # more /etc/fstab | grep nfs UUID=e06097bb-cfcd-437b-9e4d-a691f5662a7d /store nfs rw,nosuid 0 0 If a file system found in "/etc/fstab" refers to NFS and it does not have the "nosuid" option set, this is a finding. Verify the NFS is mounted with the "nosuid" option: # mount | grep nfs | grep nosuid If no results are returned, this is a finding.

Fix: F-4606r88639_fix

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

b
The Red Hat Enterprise Linux operating system must prevent binary files from being executed on file systems that are being imported via Network File System (NFS).
CM-6 - Medium - CCI-000366 - V-204483 - SV-204483r603261_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-021021
Vuln IDs
  • V-204483
  • V-73161
Rule IDs
  • SV-204483r603261_rule
  • SV-87813
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.
Checks: C-4607r88641_chk

Verify file systems that are being NFS imported are configured with the "noexec" option. Find the file system(s) that contain the directories being imported with the following command: # more /etc/fstab | grep nfs UUID=e06097bb-cfcd-437b-9e4d-a691f5662a7d /store nfs rw,noexec 0 0 If a file system found in "/etc/fstab" refers to NFS and it does not have the "noexec" option set, and use of NFS imported binaries is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding. Verify the NFS is mounted with the "noexec"option: # mount | grep nfs | grep noexec If no results are returned and use of NFS imported binaries is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding.

Fix: F-4607r88642_fix

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

a
The Red Hat Enterprise Linux operating system must mount /dev/shm with secure options.
CM-7 - Low - CCI-001764 - V-204486 - SV-204486r853900_rule
RMF Control
CM-7
Severity
Low
CCI
CCI-001764
Version
RHEL-07-021024
Vuln IDs
  • V-204486
  • V-81013
Rule IDs
  • SV-204486r853900_rule
  • SV-95725
The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files as they may be incompatible. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access. The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
Checks: C-4610r462552_chk

Verify that the "nodev","nosuid", and "noexec" options are configured for /dev/shm: # cat /etc/fstab | grep /dev/shm tmpfs /dev/shm tmpfs defaults,nodev,nosuid,noexec 0 0 If results are returned and the "nodev", "nosuid", or "noexec" options are missing, this is a finding. Verify "/dev/shm" is mounted with the "nodev", "nosuid", and "noexec" options: # mount | grep /dev/shm tmpfs on /dev/shm type tmpfs (rw,nodev,nosuid,noexec,seclabel) If /dev/shm is mounted without secure options "nodev", "nosuid", and "noexec", this is a finding.

Fix: F-4610r462553_fix

Configure the system so that /dev/shm is mounted with the "nodev", "nosuid", and "noexec" options by adding /modifying the /etc/fstab with the following line: tmpfs /dev/shm tmpfs defaults,nodev,nosuid,noexec 0 0

b
The Red Hat Enterprise Linux operating system must be configured so that all world-writable directories are group-owned by root, sys, bin, or an application group.
CM-6 - Medium - CCI-000366 - V-204487 - SV-204487r744106_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-021030
Vuln IDs
  • V-204487
  • V-72047
Rule IDs
  • SV-204487r744106_rule
  • SV-86671
If a world-writable directory is not group-owned by root, sys, bin, or an application Group Identifier (GID), unauthorized users may be able to modify files created by others. The only authorized public directories are those temporary directories supplied with the system or those designed to be temporary file repositories. The setting is normally reserved for directories used by the system and by users for temporary file storage, (e.g., /tmp), and for directories requiring global read/write access.
Checks: C-36345r602633_chk

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

Fix: F-36308r602634_fix

All directories in local partitions which are world-writable should be group-owned by root or another system account. If any world-writable directories are not group-owned by a system account, this should be investigated. Following this, the directories should be deleted or assigned to an appropriate group.

b
The Red Hat Enterprise Linux operating system must set the umask value to 077 for all local interactive user accounts.
CM-3 - Medium - CCI-000318 - V-204488 - SV-204488r861006_rule
RMF Control
CM-3
Severity
Medium
CCI
CCI-000318
Version
RHEL-07-021040
Vuln IDs
  • V-204488
  • V-72049
Rule IDs
  • SV-204488r861006_rule
  • SV-86673
The umask controls the default access mode assigned to newly created files. A umask of 077 limits new files to mode 700 or less permissive. Although umask can be represented as a four-digit number, the first digit representing special access modes is typically ignored or required to be "0". This requirement applies to the globally configured system defaults and the local interactive user defaults for each account on the system.
Checks: C-4612r858483_chk

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

Fix: F-4612r88657_fix

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

b
The Red Hat Enterprise Linux operating system must have cron logging implemented.
CM-6 - Medium - CCI-000366 - V-204489 - SV-204489r744109_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-021100
Vuln IDs
  • V-204489
  • V-72051
Rule IDs
  • SV-204489r744109_rule
  • SV-86675
Cron logging can be used to trace the successful or unsuccessful execution of cron jobs. It can also be used to spot intrusions into the use of the cron facility by unauthorized and malicious users.
Checks: C-4613r744107_chk

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

Fix: F-4613r744108_fix

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

b
The Red Hat Enterprise Linux operating system must be configured so that the cron.allow file, if it exists, is owned by root.
CM-6 - Medium - CCI-000366 - V-204490 - SV-204490r603261_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-021110
Vuln IDs
  • V-204490
  • V-72053
Rule IDs
  • SV-204490r603261_rule
  • SV-86677
If the owner of the "cron.allow" file is not set to root, the possibility exists for an unauthorized user to view or to edit sensitive information.
Checks: C-4614r88662_chk

Verify that the "cron.allow" file is owned by root. Check the owner of the "cron.allow" file with the following command: # ls -al /etc/cron.allow -rw------- 1 root root 6 Mar 5 2011 /etc/cron.allow If the "cron.allow" file exists and has an owner other than root, this is a finding.

Fix: F-4614r88663_fix

Set the owner on the "/etc/cron.allow" file to root with the following command: # chown root /etc/cron.allow

b
The Red Hat Enterprise Linux operating system must be configured so that the cron.allow file, if it exists, is group-owned by root.
CM-6 - Medium - CCI-000366 - V-204491 - SV-204491r603261_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-021120
Vuln IDs
  • V-204491
  • V-72055
Rule IDs
  • SV-204491r603261_rule
  • SV-86679
If the group owner of the "cron.allow" file is not set to root, sensitive information could be viewed or edited by unauthorized users.
Checks: C-4615r88665_chk

Verify that the "cron.allow" file is group-owned by root. Check the group owner of the "cron.allow" file with the following command: # ls -al /etc/cron.allow -rw------- 1 root root 6 Mar 5 2011 /etc/cron.allow If the "cron.allow" file exists and has a group owner other than root, this is a finding.

Fix: F-4615r88666_fix

Set the group owner on the "/etc/cron.allow" file to root with the following command: # chgrp root /etc/cron.allow

b
The Red Hat Enterprise Linux operating system must disable Kernel core dumps unless needed.
CM-6 - Medium - CCI-000366 - V-204492 - SV-204492r603261_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-021300
Vuln IDs
  • V-204492
  • V-72057
Rule IDs
  • SV-204492r603261_rule
  • SV-86681
Kernel core dumps may contain the full contents of system memory at the time of the crash. Kernel core dumps may consume a considerable amount of disk space and may result in denial of service by exhausting the available space on the target file system partition.
Checks: C-4616r88668_chk

Verify that kernel core dumps are disabled unless needed. Check the status of the "kdump" service with the following command: # systemctl status kdump.service kdump.service - Crash recovery kernel arming Loaded: loaded (/usr/lib/systemd/system/kdump.service; enabled) Active: active (exited) since Wed 2015-08-26 13:08:09 EDT; 43min ago Main PID: 1130 (code=exited, status=0/SUCCESS) kernel arming. If the "kdump" service is active, ask the System Administrator if the use of the service is required and documented with the Information System Security Officer (ISSO). If the service is active and is not documented, this is a finding.

Fix: F-4616r88669_fix

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

a
The Red Hat Enterprise Linux operating system must be configured so that a separate file system is used for user home directories (such as /home or an equivalent).
CM-6 - Low - CCI-000366 - V-204493 - SV-204493r603840_rule
RMF Control
CM-6
Severity
Low
CCI
CCI-000366
Version
RHEL-07-021310
Vuln IDs
  • V-204493
  • V-72059
Rule IDs
  • SV-204493r603840_rule
  • SV-86683
The use of separate file systems for different paths can protect the system from failures resulting from a file system becoming full or failing.
Checks: C-4617r622303_chk

Verify that a separate file system/partition has been created for non-privileged local interactive user home directories. Check the home directory assignment for all non-privileged users (those with a UID of 1000 or greater) on the system with the following command: # awk -F: '($3&gt;=1000)&amp;&amp;($7 !~ /nologin/){print $1, $3, $6, $7}' /etc/passwd adamsj 1000 /home/adamsj /bin/bash jacksonm 1001 /home/jacksonm /bin/bash smithj 1002 /home/smithj /bin/bash The output of the command will give the directory/partition that contains the home directories for the non-privileged users on the system (in this example, /home) and users' shell. All accounts with a valid shell (such as /bin/bash) are considered interactive users. Check that a file system/partition has been created for the non-privileged interactive users with the following command: Note: The partition of /home is used in the example. # grep /home /etc/fstab UUID=333ada18 /home ext4 noatime,nobarrier,nodev 1 2 If a separate entry for the file system/partition that contains the non-privileged interactive users' home directories does not exist, this is a finding.

Fix: F-4617r88672_fix

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

a
The Red Hat Enterprise Linux operating system must use a separate file system for /var.
CM-6 - Low - CCI-000366 - V-204494 - SV-204494r603261_rule
RMF Control
CM-6
Severity
Low
CCI
CCI-000366
Version
RHEL-07-021320
Vuln IDs
  • V-204494
  • V-72061
Rule IDs
  • SV-204494r603261_rule
  • SV-86685
The use of separate file systems for different paths can protect the system from failures resulting from a file system becoming full or failing.
Checks: C-4618r88674_chk

Verify that a separate file system/partition has been created for "/var". Check that a file system/partition has been created for "/var" with the following command: # grep /var /etc/fstab UUID=c274f65f /var ext4 noatime,nobarrier 1 2 If a separate entry for "/var" is not in use, this is a finding.

Fix: F-4618r88675_fix

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

a
The Red Hat Enterprise Linux operating system must use a separate file system for the system audit data path.
CM-6 - Low - CCI-000366 - V-204495 - SV-204495r603261_rule
RMF Control
CM-6
Severity
Low
CCI
CCI-000366
Version
RHEL-07-021330
Vuln IDs
  • V-204495
  • V-72063
Rule IDs
  • SV-204495r603261_rule
  • SV-86687
The use of separate file systems for different paths can protect the system from failures resulting from a file system becoming full or failing.
Checks: C-4619r88677_chk

Determine if the operating system is configured to have the "/var/log/audit" path is on a separate file system. # grep /var/log/audit /etc/fstab If no result is returned, or the operating system is not configured to have "/var/log/audit" on a separate file system, this is a finding. Verify that "/var/log/audit" is mounted on a separate file system: # mount | grep "/var/log/audit" If no result is returned, or "/var/log/audit" is not on a separate file system, this is a finding.

Fix: F-4619r88678_fix

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

a
The Red Hat Enterprise Linux operating system must use a separate file system for /tmp (or equivalent).
CM-6 - Low - CCI-000366 - V-204496 - SV-204496r603261_rule
RMF Control
CM-6
Severity
Low
CCI
CCI-000366
Version
RHEL-07-021340
Vuln IDs
  • V-204496
  • V-72065
Rule IDs
  • SV-204496r603261_rule
  • SV-86689
The use of separate file systems for different paths can protect the system from failures resulting from a file system becoming full or failing.
Checks: C-36346r602636_chk

Verify that a separate file system/partition has been created for "/tmp". Check that a file system/partition has been created for "/tmp" with the following command: # systemctl is-enabled tmp.mount enabled If the "tmp.mount" service is not enabled, check to see if "/tmp" is defined in the fstab with a device and mount point: # grep -i /tmp /etc/fstab UUID=a411dc99-f2a1-4c87-9e05-184977be8539 /tmp ext4 rw,relatime,discard,data=ordered,nosuid,noexec, 0 0 If "tmp.mount" service is not enabled or the "/tmp" directory is not defined in the fstab with a device and mount point, this is a finding.

Fix: F-36309r602637_fix

Start the "tmp.mount" service with the following command: # systemctl enable tmp.mount OR Edit the "/etc/fstab" file and ensure the "/tmp" directory is defined in the fstab with a device and mount point.

c
The Red Hat Enterprise Linux operating system must implement NIST FIPS-validated cryptography for the following: to provision digital signatures, to generate cryptographic hashes, and to protect data requiring data-at-rest protections in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards.
AC-17 - High - CCI-000068 - V-204497 - SV-204497r877398_rule
RMF Control
AC-17
Severity
High
CCI
CCI-000068
Version
RHEL-07-021350
Vuln IDs
  • V-204497
  • V-72067
Rule IDs
  • SV-204497r877398_rule
  • SV-86691
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. Satisfies: SRG-OS-000033-GPOS-00014, SRG-OS-000185-GPOS-00079, SRG-OS-000396-GPOS-00176, SRG-OS-000405-GPOS-00184, SRG-OS-000478-GPOS-00223
Checks: C-36347r602639_chk

Verify the operating system implements DoD-approved encryption to protect the confidentiality of remote access sessions. Check to see if the "dracut-fips" package is installed with the following command: # yum list installed dracut-fips dracut-fips-033-360.el7_2.x86_64.rpm If a "dracut-fips" package is installed, check to see if the kernel command line is configured to use FIPS mode with the following command: Note: GRUB 2 reads its configuration from the "/boot/grub2/grub.cfg" file on traditional BIOS-based machines and from the "/boot/efi/EFI/redhat/grub.cfg" file on UEFI machines. # grep fips /boot/grub2/grub.cfg /vmlinuz-3.8.0-0.40.el7.x86_64 root=/dev/mapper/rhel-root ro rd.md=0 rd.dm=0 rd.lvm.lv=rhel/swap crashkernel=auto rd.luks=0 vconsole.keymap=us rd.lvm.lv=rhel/root rhgb fips=1 quiet If the kernel command line is configured to use FIPS mode, check to see if the system is in FIPS mode with the following command: # cat /proc/sys/crypto/fips_enabled 1 If a "dracut-fips" package is not installed, the kernel command line does not have a fips entry, or the system has a value of "0" for "fips_enabled" in "/proc/sys/crypto", this is a finding. Verify the file /etc/system-fips exists. # ls -l /etc/system-fips If this file does not exist, this is a finding.

Fix: F-36310r602640_fix

Configure the operating system to implement DoD-approved encryption by installing the dracut-fips package. To enable strict FIPS compliance, the fips=1 kernel option needs to be added to the kernel command line during system installation so key generation is done with FIPS-approved algorithms and continuous monitoring tests in place. Configure the operating system to implement DoD-approved encryption by following the steps below: 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 should also ensure that 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 non-unique key. Install the dracut-fips package with the following command: # yum install dracut-fips Recreate the "initramfs" file with the following command: Note: This command will overwrite the existing "initramfs" file. # dracut -f Modify the kernel command line of the current kernel in the "grub.cfg" file by adding the following option to the GRUB_CMDLINE_LINUX key in the "/etc/default/grub" file and then rebuild the "grub.cfg" file: fips=1 Changes to "/etc/default/grub" require rebuilding the "grub.cfg" file as follows: On BIOS-based machines, use the following command: # grub2-mkconfig -o /boot/grub2/grub.cfg On UEFI-based machines, use the following command: # grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg If /boot or /boot/efi reside on separate partitions, the kernel parameter boot=<partition of /boot or /boot/efi> must be added to the kernel command line. You can identify a partition by running the df /boot or df /boot/efi command: # df /boot Filesystem 1K-blocks Used Available Use% Mounted on /dev/sda1 495844 53780 416464 12% /boot To ensure the "boot=" configuration option will work even if device naming changes occur between boots, identify the universally unique identifier (UUID) of the partition with the following command: # blkid /dev/sda1 /dev/sda1: UUID="05c000f1-a213-759e-c7a2-f11b7424c797" TYPE="ext4" For the example above, append the following string to the kernel command line: boot=UUID=05c000f1-a213-759e-c7a2-f11b7424c797 If the file /etc/system-fips does not exists, recreate it: # touch /etc/ system-fips Reboot the system for the changes to take effect.

a
The Red Hat Enterprise Linux operating system must be configured so that the file integrity tool is configured to verify Access Control Lists (ACLs).
CM-6 - Low - CCI-000366 - V-204498 - SV-204498r880856_rule
RMF Control
CM-6
Severity
Low
CCI
CCI-000366
Version
RHEL-07-021600
Vuln IDs
  • V-204498
  • V-72069
Rule IDs
  • SV-204498r880856_rule
  • SV-86693
ACLs can provide permissions beyond those permitted through the file mode and must be verified by file integrity tools.
Checks: C-4622r880855_chk

Verify the file integrity tool is configured to verify ACLs. Note: AIDE is highly configurable at install time. These commands assume the "aide.conf" file is under the "/etc" directory. Use the following command to determine if the file is in another location: # find / -name aide.conf Check the "aide.conf" file to determine if the "acl" rule has been added to the rule list being applied to the files and directories selection lists. An example rule that includes the "acl" rule is below: All= p+i+n+u+g+s+m+S+sha512+acl+xattrs+selinux /bin All # apply the custom rule to the files in bin /sbin All # apply the same custom rule to the files in sbin If the "acl" rule is not being used on all uncommented selection lines in the "/etc/aide.conf" file, or ACLs are not being checked by another file integrity tool, this is a finding.

Fix: F-4622r88687_fix

Configure the file integrity tool to check file and directory ACLs. If AIDE is installed, ensure the "acl" rule is present on all uncommented file and directory selection lists.

a
The Red Hat Enterprise Linux operating system must be configured so that the file integrity tool is configured to verify extended attributes.
CM-6 - Low - CCI-000366 - V-204499 - SV-204499r880858_rule
RMF Control
CM-6
Severity
Low
CCI
CCI-000366
Version
RHEL-07-021610
Vuln IDs
  • V-204499
  • V-72071
Rule IDs
  • SV-204499r880858_rule
  • SV-86695
Extended attributes in file systems are used to contain arbitrary data and file metadata with security implications.
Checks: C-4623r880857_chk

Verify the file integrity tool is configured to verify extended attributes. Note: AIDE is highly configurable at install time. These commands assume the "aide.conf" file is under the "/etc" directory. Use the following command to determine if the file is in another location: # find / -name aide.conf Check the "aide.conf" file to determine if the "xattrs" rule has been added to the rule list being applied to the files and directories selection lists. An example rule that includes the "xattrs" rule follows: All= p+i+n+u+g+s+m+S+sha512+acl+xattrs+selinux /bin All # apply the custom rule to the files in bin /sbin All # apply the same custom rule to the files in sbin If the "xattrs" rule is not being used on all uncommented selection lines in the "/etc/aide.conf" file, or extended attributes are not being checked by another file integrity tool, this is a finding.

Fix: F-4623r88690_fix

Configure the file integrity tool to check file and directory extended attributes. If AIDE is installed, ensure the "xattrs" rule is present on all uncommented file and directory selection lists.

b
The Red Hat Enterprise Linux operating system must use a file integrity tool that is configured to use FIPS 140-2 approved cryptographic hashes for validating file contents and directories.
CM-6 - Medium - CCI-000366 - V-204500 - SV-204500r880860_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-021620
Vuln IDs
  • V-204500
  • V-72073
Rule IDs
  • SV-204500r880860_rule
  • SV-86697
File integrity tools use cryptographic hashes for verifying file contents and directories have not been altered. These hashes must be FIPS 140-2 approved cryptographic hashes. Red Hat Enterprise Linux operating system installation media ships with an optional file integrity tool called Advanced Intrusion Detection Environment (AIDE). AIDE is highly configurable at install time. This requirement assumes the "aide.conf" file is under the "/etc" directory.
Checks: C-4624r880859_chk

Verify the file integrity tool is configured to use FIPS 140-2-approved cryptographic hashes for validating file contents and directories. Note: AIDE is highly configurable at install time. These commands assume the "aide.conf" file is under the "/etc" directory. Use the following command to determine if the file is in another location: # find / -name aide.conf Check the "aide.conf" file to determine if the "sha512" rule has been added to the rule list being applied to the files and directories selection lists. Exclude any log files, or files expected to change frequently, to reduce unnecessary notifications. An example rule that includes the "sha512" rule follows: All=p+i+n+u+g+s+m+S+sha512+acl+xattrs+selinux /bin All # apply the custom rule to the files in bin /sbin All # apply the same custom rule to the files in sbin If the "sha512" rule is not being used on all uncommented selection lines in the "/etc/aide.conf" file, or another file integrity tool is not using FIPS 140-2-approved cryptographic hashes for validating file contents and directories, this is a finding.

Fix: F-4624r792830_fix

Configure the file integrity tool to use FIPS 140-2 cryptographic hashes for validating file and directory contents. If AIDE is installed, ensure the "sha512" rule is present on all uncommented file and directory selection lists. Exclude any log files, or files expected to change frequently, to reduce unnecessary notifications.

b
The Red Hat Enterprise Linux operating system must not allow removable media to be used as the boot loader unless approved.
CM-3 - Medium - CCI-000318 - V-204501 - SV-204501r928576_rule
RMF Control
CM-3
Severity
Medium
CCI
CCI-000318
Version
RHEL-07-021700
Vuln IDs
  • V-204501
  • V-72075
Rule IDs
  • SV-204501r928576_rule
  • SV-86699
Malicious users with removable boot media can gain access to a system configured to use removable media as the boot loader. If removable media is designed to be used as the boot loader, the requirement must be documented with the information system security officer (ISSO).
Checks: C-4625r928575_chk

Verify the system is not configured to use a boot loader on removable media. Note: GRUB 2 reads its configuration from the "/boot/grub2/grub.cfg" file on traditional BIOS-based machines and from the "/boot/efi/EFI/redhat/grub.cfg" file on UEFI machines. Check for the existence of alternate boot loader configuration files with the following command: # find / -name grub.cfg /boot/efi/EFI/redhat/grub.cfg If a "grub.cfg" is found in any subdirectories other than "/boot/grub2/" and "/boot/efi/EFI/redhat/", ask the system administrator (SA) if there is documentation signed by the ISSO to approve the use of removable media as a boot loader. List the number of menu entries defined in the grub configuration file with the following command (the number will vary between systems): # grep -cw menuentry /boot/efi/EFI/redhat/grub.cfg 4 Check that the grub configuration file has the "set root" command for each menu entry with the following command ("set root" defines the disk and partition or directory where the kernel and GRUB 2 modules are stored): # grep 'set root' /boot/efi/EFI/redhat/grub.cfg set root='hd0,gpt2' set root='hd0,gpt2' set root='hd0,gpt2' set root='hd0,gpt2' If the system is using an alternate boot loader on removable media, and documentation does not exist approving the alternate configuration, this is a finding.

Fix: F-4625r88696_fix

Remove alternate methods of booting the system from removable media or document the configuration to boot from removable media with the ISSO.

c
The Red Hat Enterprise Linux operating system must not have the telnet-server package installed.
CM-7 - High - CCI-000381 - V-204502 - SV-204502r603261_rule
RMF Control
CM-7
Severity
High
CCI
CCI-000381
Version
RHEL-07-021710
Vuln IDs
  • V-204502
  • V-72077
Rule IDs
  • SV-204502r603261_rule
  • SV-86701
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.
Checks: C-4626r88698_chk

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. Check to see if the telnet-server package is installed with the following command: # yum list installed telnet-server If the telnet-server package is installed, this is a finding.

Fix: F-4626r88699_fix

Configure the operating system to disable non-essential capabilities by removing the telnet-server package from the system with the following command: # yum remove telnet-server

b
The Red Hat Enterprise Linux operating system must be configured so that auditing is configured to produce records containing information to establish what type of events occurred, where the events occurred, the source of the events, and the outcome of the events. These audit records must also identify individual identities of group account users.
AU-2 - Medium - CCI-000126 - V-204503 - SV-204503r603261_rule
RMF Control
AU-2
Severity
Medium
CCI
CCI-000126
Version
RHEL-07-030000
Vuln IDs
  • V-204503
  • V-72079
Rule IDs
  • SV-204503r603261_rule
  • SV-86703
Without establishing what type of events occurred, 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 the operating system audit logs provides a means of investigating an attack; recognizing resource utilization or capacity thresholds; or identifying an improperly configured operating system. Satisfies: SRG-OS-000038-GPOS-00016, SRG-OS-000039-GPOS-00017, SRG-OS-000042-GPOS-00021, SRG-OS-000254-GPOS-00095, SRG-OS-000255-GPOS-00096
Checks: C-36348r602642_chk

Verify the operating system produces audit records containing information to establish when (date and time) the events occurred. Check to see if auditing is active by issuing the following command: # systemctl is-active auditd.service active If the "auditd" status is not active, this is a finding.

Fix: F-36311r602643_fix

Configure the operating system to produce audit records containing information to establish when (date and time) the events occurred. Enable the auditd service with the following command: # systemctl start auditd.service

b
The Red Hat Enterprise Linux operating system must shut down upon audit processing failure, unless availability is an overriding concern. If availability is a concern, the system must alert the designated staff (System Administrator [SA] and Information System Security Officer [ISSO] at a minimum) in the event of an audit processing failure.
AU-5 - Medium - CCI-000139 - V-204504 - SV-204504r880761_rule
RMF Control
AU-5
Severity
Medium
CCI
CCI-000139
Version
RHEL-07-030010
Vuln IDs
  • V-204504
  • V-72081
Rule IDs
  • SV-204504r880761_rule
  • SV-86705
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. Satisfies: SRG-OS-000046-GPOS-00022, SRG-OS-000047-GPOS-00023
Checks: C-4628r880759_chk

Confirm the audit configuration regarding how auditing processing failures are handled. Check to see what level "auditctl" is set to with following command: # auditctl -s | grep -i "fail" failure 2 Note: If the value of "failure" is set to "2", the system is configured to panic (shut down) in the event of an auditing failure. If the value of "failure" is set to "1", the system will not shut down and instead will record the audit failure in the kernel log. If the system is configured as per requirement RHEL-07-031000, the kernel log will be sent to a log aggregation server and generate an alert. If the "failure" setting is set to any value other than "1" or "2", this is a finding. If the "failure" setting is not set, this should be upgraded to a CAT I finding. If the "failure" setting is set to "1" but the availability concern is not documented or there is no monitoring of the kernel log, this should be downgraded to a CAT III finding.

Fix: F-4628r880760_fix

Configure the operating system to shut down in the event of an audit processing failure. Add or correct the option to shut down the operating system with the following command: # auditctl -f 2 Edit the "/etc/audit/rules.d/audit.rules" file and add the following line: -f 2 If availability has been determined to be more important, and this decision is documented with the ISSO, configure the operating system to notify system administration staff and ISSO staff in the event of an audit processing failure with the following command: # auditctl -f 1 Edit the "/etc/audit/rules.d/audit.rules" file and add the following line: -f 1 Kernel log monitoring must also be configured to properly alert designated staff. The audit daemon must be restarted for the changes to take effect.

b
The Red Hat Enterprise Linux operating system must be configured to off-load audit logs onto a different system or storage media from the system being audited.
AU-4 - Medium - CCI-001851 - V-204506 - SV-204506r877390_rule
RMF Control
AU-4
Severity
Medium
CCI
CCI-001851
Version
RHEL-07-030201
Vuln IDs
  • V-204506
  • V-81017
Rule IDs
  • SV-204506r877390_rule
  • SV-95729
Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Off-loading is a common process in information systems with limited audit storage capacity. One method of off-loading audit logs in Red Hat Enterprise Linux is with the use of the audisp-remote dameon. Without the configuration of the "au-remote" plugin, the audisp-remote daemon will not off load the logs from the system being audited. Satisfies: SRG-OS-000342-GPOS-00133, SRG-OS-000479-GPOS-00224
Checks: C-4630r462469_chk

Verify the "au-remote" plugin is configured to always off-load audit logs using the audisp-remote daemon: # cat /etc/audisp/plugins.d/au-remote.conf | grep -v "^#" active = yes direction = out path = /sbin/audisp-remote type = always format = string If "active" is not set to "yes", "direction" is not set to "out", "path" is not set to "/sbin/audisp-remote", "type" is not set to "always", or any of the lines are commented out, ask the System Administrator to indicate how the audit logs are off-loaded to a different system or storage media. If there is no evidence that the system is configured to off-load audit logs to a different system or storage media, this is a finding.

Fix: F-4630r858479_fix

Edit the /etc/audisp/plugins.d/au-remote.conf file and add or update the following values: active = yes direction = out path = /sbin/audisp-remote type = always The audit daemon must be restarted for changes to take effect: # service auditd restart

b
The Red Hat Enterprise Linux operating system must take appropriate action when the remote logging buffer is full.
AU-4 - Medium - CCI-001851 - V-204507 - SV-204507r877390_rule
RMF Control
AU-4
Severity
Medium
CCI
CCI-001851
Version
RHEL-07-030210
Vuln IDs
  • V-204507
  • V-81019
Rule IDs
  • SV-204507r877390_rule
  • SV-95731
Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Off-loading is a common process in information systems with limited audit storage capacity. One method of off-loading audit logs in Red Hat Enterprise Linux is with the use of the audisp-remote dameon. When the remote buffer is full, audit logs will not be collected and sent to the central log server. Satisfies: SRG-OS-000342-GPOS-00133, SRG-OS-000479-GPOS-00224
Checks: C-36349r602645_chk

Verify the audisp daemon is configured to take an appropriate action when the internal queue is full: # grep "overflow_action" /etc/audisp/audispd.conf overflow_action = syslog If the "overflow_action" option is not "syslog", "single", or "halt", or the line is commented out, ask the System Administrator to indicate how the audit logs are off-loaded to a different system or storage media, and to indicate what action that system takes when the internal queue is full. If there is no evidence the system is configured to off-load audit logs to a different system or storage media or, if the configuration does not take appropriate action when the internal queue is full, this is a finding.

Fix: F-36312r602646_fix

Edit the /etc/audisp/audispd.conf file and add or update the "overflow_action" option: overflow_action = syslog The audit daemon must be restarted for changes to take effect: # service auditd restart

b
The Red Hat Enterprise Linux operating system must label all off-loaded audit logs before sending them to the central log server.
AU-4 - Medium - CCI-001851 - V-204508 - SV-204508r877390_rule
RMF Control
AU-4
Severity
Medium
CCI
CCI-001851
Version
RHEL-07-030211
Vuln IDs
  • V-204508
  • V-81021
Rule IDs
  • SV-204508r877390_rule
  • SV-95733
Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Off-loading is a common process in information systems with limited audit storage capacity. One method of off-loading audit logs in Red Hat Enterprise Linux is with the use of the audisp-remote dameon. 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. Satisfies: SRG-OS-000342-GPOS-00133, SRG-OS-000479-GPOS-00224
Checks: C-36350r602648_chk

Verify the audisp daemon is configured to label all off-loaded audit logs: # grep "name_format" /etc/audisp/audispd.conf name_format = hostname If the "name_format" option is not "hostname", "fqd", or "numeric", or the line is commented out, ask the System Administrator to indicate how the audit logs are off-loaded to a different system or storage media, and to indicate if the logs are labeled appropriately. If there is no evidence that the system is configured to off-load audit logs to a different system or storage media, or if the configuration does not appropriately label logs before they are off-loaded, this is a finding.

Fix: F-36313r602649_fix

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

b
The Red Hat Enterprise Linux operating system must off-load audit records onto a different system or media from the system being audited.
AU-4 - Medium - CCI-001851 - V-204509 - SV-204509r877390_rule
RMF Control
AU-4
Severity
Medium
CCI
CCI-001851
Version
RHEL-07-030300
Vuln IDs
  • V-204509
  • V-72083
Rule IDs
  • SV-204509r877390_rule
  • SV-86707
Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Off-loading is a common process in information systems with limited audit storage capacity. Satisfies: SRG-OS-000342-GPOS-00133, SRG-OS-000479-GPOS-00224
Checks: C-4633r88719_chk

Verify the operating system off-loads audit records onto a different system or media from the system being audited. To determine the remote server that the records are being sent to, use the following command: # grep -i remote_server /etc/audisp/audisp-remote.conf remote_server = 10.0.21.1 If a remote server is not configured, or the line is commented out, ask the System Administrator to indicate how the audit logs are off-loaded to a different system or media. If there is no evidence that the audit logs are being off-loaded to another system or media, this is a finding.

Fix: F-4633r88720_fix

Configure the operating system to off-load audit records onto a different system or media from the system being audited. Set the remote server option in "/etc/audisp/audisp-remote.conf" with the IP address of the log aggregation server.

b
The Red Hat Enterprise Linux operating system must encrypt the transfer of audit records off-loaded onto a different system or media from the system being audited.
AU-4 - Medium - CCI-001851 - V-204510 - SV-204510r877390_rule
RMF Control
AU-4
Severity
Medium
CCI
CCI-001851
Version
RHEL-07-030310
Vuln IDs
  • V-204510
  • V-72085
Rule IDs
  • SV-204510r877390_rule
  • SV-86709
Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Off-loading is a common process in information systems with limited audit storage capacity. Satisfies: SRG-OS-000342-GPOS-00133, SRG-OS-000479-GPOS-00224
Checks: C-4634r88722_chk

Verify the operating system encrypts audit records off-loaded onto a different system or media from the system being audited. To determine if the transfer is encrypted, use the following command: # grep -i enable_krb5 /etc/audisp/audisp-remote.conf enable_krb5 = yes If the value of the "enable_krb5" option is not set to "yes" or the line is commented out, ask the System Administrator to indicate how the audit logs are off-loaded to a different system or media. If there is no evidence that the transfer of the audit logs being off-loaded to another system or media is encrypted, this is a finding.

Fix: F-4634r88723_fix

Configure the operating system to encrypt the transfer of off-loaded audit records onto a different system or media from the system being audited. Uncomment the "enable_krb5" option in "/etc/audisp/audisp-remote.conf" and set it with the following line: enable_krb5 = yes

b
The Red Hat Enterprise Linux operating system must be configured so that the audit system takes appropriate action when the audit storage volume is full.
AU-4 - Medium - CCI-001851 - V-204511 - SV-204511r877390_rule
RMF Control
AU-4
Severity
Medium
CCI
CCI-001851
Version
RHEL-07-030320
Vuln IDs
  • V-204511
  • V-72087
Rule IDs
  • SV-204511r877390_rule
  • SV-86711
Taking appropriate action in case of a filled audit storage volume will minimize the possibility of losing audit records. One method of off-loading audit logs in Red Hat Enterprise Linux is with the use of the audisp-remote dameon.
Checks: C-36351r602651_chk

Verify the action the operating system takes if the disk the audit records are written to becomes full. To determine the action that takes place if the disk is full on the remote server, use the following command: # grep -i disk_full_action /etc/audisp/audisp-remote.conf disk_full_action = single If the value of the "disk_full_action" option is not "syslog", "single", or "halt", or the line is commented out, ask the System Administrator to indicate how the audit logs are off-loaded to a different system or storage media, and to indicate the action taken when the disk is full on the remote server. If there is no evidence that the system is configured to off-load audit logs to a different system or storage media, or if the configuration does not take appropriate action when the disk is full on the remote server, this is a finding.

Fix: F-36314r602652_fix

Configure the action the operating system takes if the disk the audit records are written to becomes full. Uncomment or edit the "disk_full_action" option in "/etc/audisp/audisp-remote.conf" and set it to "syslog", "single", or "halt", such as the following line: disk_full_action = single

b
The Red Hat Enterprise Linux operating system must be configured so that the audit system takes appropriate action when there is an error sending audit records to a remote system.
AU-4 - Medium - CCI-001851 - V-204512 - SV-204512r877390_rule
RMF Control
AU-4
Severity
Medium
CCI
CCI-001851
Version
RHEL-07-030321
Vuln IDs
  • V-204512
  • V-73163
Rule IDs
  • SV-204512r877390_rule
  • SV-87815
Taking appropriate action when there is an error sending audit records to a remote system will minimize the possibility of losing audit records. One method of off-loading audit logs in Red Hat Enterprise Linux is with the use of the audisp-remote dameon.
Checks: C-36352r602654_chk

Verify the action the operating system takes if there is an error sending audit records to a remote system. Check the action that takes place if there is an error sending audit records to a remote system with the following command: # grep -i network_failure_action /etc/audisp/audisp-remote.conf network_failure_action = syslog If the value of the "network_failure_action" option is not "syslog", "single", or "halt", or the line is commented out, ask the System Administrator to indicate how the audit logs are off-loaded to a different system or storage media, and to indicate the action taken if there is an error sending audit records to the remote system. If there is no evidence that the system is configured to off-load audit logs to a different system or storage media, or if the configuration does not take appropriate action if there is an error sending audit records to the remote system, this is a finding.

Fix: F-36315r602655_fix

Configure the action the operating system takes if there is an error sending audit records to a remote system. Uncomment the "network_failure_action" option in "/etc/audisp/audisp-remote.conf" and set it to "syslog", "single", or "halt". network_failure_action = syslog

b
The Red Hat Enterprise Linux operating system must initiate an action to notify the System Administrator (SA) and Information System Security Officer ISSO, at a minimum, when allocated audit record storage volume reaches 75% of the repository maximum audit record storage capacity.
AU-5 - Medium - CCI-001855 - V-204513 - SV-204513r877389_rule
RMF Control
AU-5
Severity
Medium
CCI
CCI-001855
Version
RHEL-07-030330
Vuln IDs
  • V-204513
  • V-72089
Rule IDs
  • SV-204513r877389_rule
  • SV-86713
If security personnel are not notified immediately when storage volume reaches 75 percent utilization, they are unable to plan for audit record storage capacity expansion.
Checks: C-4637r744110_chk

Verify the operating system initiates 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. Check the system configuration to determine the partition the audit records are being written to with the following command: $ sudo grep -iw log_file /etc/audit/auditd.conf log_file = /var/log/audit/audit.log Determine what the threshold is for the system to take action when 75 percent of the repository maximum audit record storage capacity is reached: $ sudo grep -iw space_left /etc/audit/auditd.conf space_left = 25% If the value of the "space_left" keyword is not set to 25 percent of the total partition size, this is a finding.

Fix: F-4637r744111_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. Set the value of the "space_left" keyword in "/etc/audit/auditd.conf" to 25 percent of the partition size. space_left = 25% Reload the auditd daemon to apply changes made to the "/etc/audit/auditd.conf" file.

b
The Red Hat Enterprise Linux operating system must immediately notify the System Administrator (SA) and Information System Security Officer (ISSO) (at a minimum) via email when the threshold for the repository maximum audit record storage capacity is reached.
AU-5 - Medium - CCI-001855 - V-204514 - SV-204514r877389_rule
RMF Control
AU-5
Severity
Medium
CCI
CCI-001855
Version
RHEL-07-030340
Vuln IDs
  • V-204514
  • V-72091
Rule IDs
  • SV-204514r877389_rule
  • SV-86715
If security personnel are not notified immediately when the threshold for the repository maximum audit record storage capacity is reached, they are unable to expand the audit record storage capacity before records are lost.
Checks: C-4638r88734_chk

Verify the operating system immediately notifies the SA and ISSO (at a minimum) via email when the allocated audit record storage volume reaches 75 percent of the repository maximum audit record storage capacity. Check what action the operating system takes when the threshold for the repository maximum audit record storage capacity is reached with the following command: # grep -i space_left_action /etc/audit/auditd.conf space_left_action = email If the value of the "space_left_action" keyword is not set to "email", this is a finding.

Fix: F-4638r88735_fix

Configure the operating system to immediately notify the SA and ISSO (at a minimum) when the threshold for the repository maximum audit record storage capacity is reached. Uncomment or edit the "space_left_action" keyword in "/etc/audit/auditd.conf" and set it to "email". space_left_action = email

b
The Red Hat Enterprise Linux operating system must immediately notify the System Administrator (SA) and Information System Security Officer (ISSO) (at a minimum) when the threshold for the repository maximum audit record storage capacity is reached.
AU-5 - Medium - CCI-001855 - V-204515 - SV-204515r877389_rule
RMF Control
AU-5
Severity
Medium
CCI
CCI-001855
Version
RHEL-07-030350
Vuln IDs
  • V-204515
  • V-72093
Rule IDs
  • SV-204515r877389_rule
  • SV-86717
If security personnel are not notified immediately when the threshold for the repository maximum audit record storage capacity is reached, they are unable to expand the audit record storage capacity before records are lost.
Checks: C-4639r88737_chk

Verify the operating system immediately notifies the SA and ISSO (at a minimum) via email when the threshold for the repository maximum audit record storage capacity is reached. Check what account the operating system emails when the threshold for the repository maximum audit record storage capacity is reached with the following command: # grep -i action_mail_acct /etc/audit/auditd.conf action_mail_acct = root If the value of the "action_mail_acct" keyword is not set to "root" and other accounts for security personnel, this is a finding.

Fix: F-4639r88738_fix

Configure the operating system to immediately notify the SA and ISSO (at a minimum) when the threshold for the repository maximum audit record storage capacity is reached. Uncomment or edit the "action_mail_acct" keyword in "/etc/audit/auditd.conf" and set it to root and any other accounts associated with security personnel. action_mail_acct = root

b
The Red Hat Enterprise Linux operating system must audit all executions of privileged functions.
AC-6 - Medium - CCI-002234 - V-204516 - SV-204516r853914_rule
RMF Control
AC-6
Severity
Medium
CCI
CCI-002234
Version
RHEL-07-030360
Vuln IDs
  • V-204516
  • V-72095
Rule IDs
  • SV-204516r853914_rule
  • SV-86719
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.
Checks: C-4640r88740_chk

Verify the operating system audits the execution of privileged functions using the following command: # grep -iw execve /etc/audit/audit.rules -a always,exit -F arch=b32 -S execve -C uid!=euid -F euid=0 -k setuid -a always,exit -F arch=b64 -S execve -C uid!=euid -F euid=0 -k setuid -a always,exit -F arch=b32 -S execve -C gid!=egid -F egid=0 -k setgid -a always,exit -F arch=b64 -S execve -C gid!=egid -F egid=0 -k setgid If both the "b32" and "b64" audit rules for "SUID" files are not defined, this is a finding. If both the "b32" and "b64" audit rules for "SGID" files are not defined, this is a finding.

Fix: F-4640r88741_fix

Configure the operating system to audit the execution of privileged functions. Add or update the following rules in "/etc/audit/rules.d/audit.rules": -a always,exit -F arch=b32 -S execve -C uid!=euid -F euid=0 -k setuid -a always,exit -F arch=b64 -S execve -C uid!=euid -F euid=0 -k setuid -a always,exit -F arch=b32 -S execve -C gid!=egid -F egid=0 -k setgid -a always,exit -F arch=b64 -S execve -C gid!=egid -F egid=0 -k setgid The audit daemon must be restarted for the changes to take effect.

b
The Red Hat Enterprise Linux operating system must audit all uses of the chown, fchown, fchownat, and lchown syscalls.
AU-2 - Medium - CCI-000126 - V-204517 - SV-204517r809570_rule
RMF Control
AU-2
Severity
Medium
CCI
CCI-000126
Version
RHEL-07-030370
Vuln IDs
  • V-204517
  • V-72097
Rule IDs
  • SV-204517r809570_rule
  • SV-86721
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). 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 made by all programs on the system. Therefore, it is very important to use syscall rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining syscalls into one rule whenever possible. Satisfies: SRG-OS-000064-GPOS-00033, SRG-OS-000392-GPOS-00172, SRG-OS-000458-GPOS-00203, SRG-OS-000474-GPOS-00219
Checks: C-4641r809569_chk

Verify the operating system generates audit records upon successful/unsuccessful attempts to use the "chown", "fchown", "fchownat", and "lchown" syscalls. Check the file system rules in "/etc/audit/audit.rules" with the following commands: # grep chown /etc/audit/audit.rules -a always,exit -F arch=b32 -S chown,fchown,fchownat,lchown -F auid&gt;=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S chown,fchown,fchownat,lchown -F auid&gt;=1000 -F auid!=unset -k perm_mod If both the "b32" and "b64" audit rules are not defined for the "chown", "fchown", "fchownat", and "lchown" syscalls, this is a finding.

Fix: F-4641r809192_fix

Add or update the following rule in "/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_mod -a always,exit -F arch=b64 -S chown,fchown,fchownat,lchown -F auid>=1000 -F auid!=unset -k perm_mod The audit daemon must be restarted for the changes to take effect.

b
The Red Hat Enterprise Linux operating system must audit all uses of the chmod, fchmod, and fchmodat syscalls.
AU-12 - Medium - CCI-000172 - V-204521 - SV-204521r809772_rule
RMF Control
AU-12
Severity
Medium
CCI
CCI-000172
Version
RHEL-07-030410
Vuln IDs
  • V-204521
  • V-72105
Rule IDs
  • SV-204521r809772_rule
  • SV-86729
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). 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 made by all programs on the system. Therefore, it is very important to use syscall rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining syscalls into one rule whenever possible. Satisfies: SRG-OS-000458-GPOS-00203, SRG-OS-000392-GPOS-00172, SRG-OS-000064-GPOS-00033
Checks: C-4645r809571_chk

Verify the operating system generates audit records upon successful/unsuccessful attempts to use the "chmod", "fchmod", and "fchmodat" syscalls. Check the file system rules in "/etc/audit/audit.rules" with the following command: # grep chmod /etc/audit/audit.rules -a always,exit -F arch=b32 -S chmod,fchmod,fchmodat -F auid&gt;=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S chmod,fchmod,fchmodat -F auid&gt;=1000 -F auid!=unset -k perm_mod If both the "b32" and "b64" audit rules are not defined for the "chmod", "fchmod", and "fchmodat" syscalls, this is a finding.

Fix: F-4645r809771_fix

Configure the operating system to generate audit records upon successful/unsuccessful attempts to use the "chmod", "fchmod", and "fchmodat" syscalls. Add or update the following rules in "/etc/audit/rules.d/audit.rules": -a always,exit -F arch=b32 -S chmod,fchmod,fchmodat -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S chmod,fchmod,fchmodat -F auid>=1000 -F auid!=unset -k perm_mod The audit daemon must be restarted for the changes to take effect.

b
The Red Hat Enterprise Linux operating system must audit all uses of the setxattr, fsetxattr, lsetxattr, removexattr, fremovexattr, and lremovexattr syscalls.
AU-12 - Medium - CCI-000172 - V-204524 - SV-204524r809775_rule
RMF Control
AU-12
Severity
Medium
CCI
CCI-000172
Version
RHEL-07-030440
Vuln IDs
  • V-204524
  • V-72111
Rule IDs
  • SV-204524r809775_rule
  • SV-86735
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). 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 made by all programs on the system. Therefore, it is very important to use syscall rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining syscalls into one rule whenever possible. Satisfies: SRG-OS-000458-GPOS-00203, SRG-OS-000392-GPOS-00172, SRG-OS-000064-GPOS-00033
Checks: C-4648r809773_chk

Verify the operating system generates audit records upon successful/unsuccessful attempts to use the "setxattr", "fsetxattr", "lsetxattr", "removexattr", "fremovexattr", and "lremovexattr" syscalls. Check the file system rules in "/etc/audit/audit.rules" with the following commands: # grep xattr /etc/audit/audit.rules -a always,exit -F arch=b32 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid&gt;=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid&gt;=1000 -F auid!=unset -k perm_mod If both the "b32" and "b64" audit rules are not defined for the "setxattr", "fsetxattr", "lsetxattr", "removexattr", "fremovexattr", and "lremovexattr" syscalls, this is a finding.

Fix: F-4648r809774_fix

Configure the operating system to generate audit records upon successful/unsuccessful attempts to use the "setxattr", "fsetxattr", "lsetxattr", "removexattr", "fremovexattr", and "lremovexattr" syscalls. Add or update the following rules in "/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 The audit daemon must be restarted for the changes to take effect.

b
The Red Hat Enterprise Linux operating system must audit all uses of the creat, open, openat, open_by_handle_at, truncate, and ftruncate syscalls.
AU-12 - Medium - CCI-000172 - V-204531 - SV-204531r853917_rule
RMF Control
AU-12
Severity
Medium
CCI
CCI-000172
Version
RHEL-07-030510
Vuln IDs
  • V-204531
  • V-72125
Rule IDs
  • SV-204531r853917_rule
  • SV-86749
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). 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 made by all programs on the system. Therefore, it is very important to use syscall rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining syscalls into one rule whenever possible. Satisfies: SRG-OS-000064-GPOS-00033, SRG-OS-000458-GPOS-00203, SRG-OS-000461-GPOS-00205, SRG-OS-000392-GPOS-00172
Checks: C-4655r853915_chk

Verify the operating system generates audit records upon successful/unsuccessful attempts to use the "creat", "open", "openat", "open_by_handle_at", "truncate", and "ftruncate" syscalls. Check the file system rules in "/etc/audit/audit.rules" with the following commands: # grep 'open\|truncate\|creat' /etc/audit/audit.rules -a always,exit -F arch=b32 -S creat,open,openat,open_by_handle_at,truncate,ftruncate -F exit=-EPERM -F auid&gt;=1000 -F auid!=unset -k access -a always,exit -F arch=b32 -S creat,open,openat,open_by_handle_at,truncate,ftruncate -F exit=-EACCES -F auid&gt;=1000 -F auid!=unset -k access -a always,exit -F arch=b64 -S creat,open,openat,open_by_handle_at,truncate,ftruncate -F exit=-EPERM -F auid&gt;=1000 -F auid!=unset -k access -a always,exit -F arch=b64 -S creat,open,openat,open_by_handle_at,truncate,ftruncate -F exit=-EACCES -F auid&gt;=1000 -F auid!=unset -k access If both the "b32" and "b64" audit rules are not defined for the "creat", "open", "openat", "open_by_handle_at", "truncate", and "ftruncate" syscalls, this is a finding. If the output does not produce rules containing "-F exit=-EPERM", this is a finding. If the output does not produce rules containing "-F exit=-EACCES", this is a finding.

Fix: F-4655r853916_fix

Configure the operating system to generate audit records upon successful/unsuccessful attempts to use the "creat", "open", "openat", "open_by_handle_at", "truncate", and "ftruncate" syscalls. Add or update the following rules in "/etc/audit/rules.d/audit.rules": -a always,exit -F arch=b32 -S creat,open,openat,open_by_handle_at,truncate,ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -k access -a always,exit -F arch=b32 -S creat,open,openat,open_by_handle_at,truncate,ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -k access -a always,exit -F arch=b64 -S creat,open,openat,open_by_handle_at,truncate,ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -k access -a always,exit -F arch=b64 -S creat,open,openat,open_by_handle_at,truncate,ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -k access The audit daemon must be restarted for the changes to take effect.

b
The Red Hat Enterprise Linux operating system must audit all uses of the semanage command.
AU-12 - Medium - CCI-000172 - V-204536 - SV-204536r861014_rule
RMF Control
AU-12
Severity
Medium
CCI
CCI-000172
Version
RHEL-07-030560
Vuln IDs
  • V-204536
  • V-72135
Rule IDs
  • SV-204536r861014_rule
  • SV-86759
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). 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-000392-GPOS-00172, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209
Checks: C-4660r861012_chk

Verify the operating system generates audit records when successful/unsuccessful attempts to use the "semanage" command occur. Check the file system rule in "/etc/audit/audit.rules" with the following command: $ sudo grep -w "/usr/sbin/semanage" /etc/audit/audit.rules -a always,exit -F path=/usr/sbin/semanage -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-priv_change If the command does not return any output, this is a finding.

Fix: F-4660r861013_fix

Configure the operating system to generate audit records when successful/unsuccessful attempts to use the "semanage" command occur. Add or update the following rule in "/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-priv_change The audit daemon must be restarted for the changes to take effect.

b
The Red Hat Enterprise Linux operating system must audit all uses of the setsebool command.
AU-12 - Medium - CCI-000172 - V-204537 - SV-204537r861017_rule
RMF Control
AU-12
Severity
Medium
CCI
CCI-000172
Version
RHEL-07-030570
Vuln IDs
  • V-204537
  • V-72137
Rule IDs
  • SV-204537r861017_rule
  • SV-86761
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). 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-000392-GPOS-00172, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209
Checks: C-4661r861015_chk

Verify the operating system generates audit records when successful/unsuccessful attempts to use the "setsebool" command occur. Check the file system rule in "/etc/audit/audit.rules" with the following command: $ sudo grep -w "/usr/sbin/setsebool" /etc/audit/audit.rules -a always,exit -F path=/usr/sbin/setsebool -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-priv_change If the command does not return any output, this is a finding.

Fix: F-4661r861016_fix

Configure the operating system to generate audit records when successful/unsuccessful attempts to use the "setsebool" command occur. Add or update the following rule in "/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-priv_change The audit daemon must be restarted for the changes to take effect.

b
The Red Hat Enterprise Linux operating system must audit all uses of the chcon command.
AU-12 - Medium - CCI-000172 - V-204538 - SV-204538r861020_rule
RMF Control
AU-12
Severity
Medium
CCI
CCI-000172
Version
RHEL-07-030580
Vuln IDs
  • V-204538
  • V-72139
Rule IDs
  • SV-204538r861020_rule
  • SV-86763
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). 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-000392-GPOS-00172, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209
Checks: C-4662r861018_chk

Verify the operating system generates audit records when successful/unsuccessful attempts to use the "chcon" command occur. Check the file system rule in "/etc/audit/audit.rules" with the following command: $ sudo grep -w "/usr/bin/chcon" /etc/audit/audit.rules -a always,exit -F path=/usr/bin/chcon -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-priv_change If the command does not return any output, this is a finding.

Fix: F-4662r861019_fix

Configure the operating system to generate audit records when successful/unsuccessful attempts to use the "chcon" command occur. Add or update the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/chcon -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.

b
The Red Hat Enterprise Linux operating system must audit all uses of the setfiles command.
AU-12 - Medium - CCI-000172 - V-204539 - SV-204539r861023_rule
RMF Control
AU-12
Severity
Medium
CCI
CCI-000172
Version
RHEL-07-030590
Vuln IDs
  • V-204539
  • V-72141
Rule IDs
  • SV-204539r861023_rule
  • SV-86765
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). 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-000392-GPOS-00172, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209
Checks: C-4663r861021_chk

Verify the operating system generates audit records when successful/unsuccessful attempts to use the "setfiles" command occur. Check the file system rule in "/etc/audit/audit.rules" with the following command: $ sudo grep -w "/usr/sbin/setfiles" /etc/audit/audit.rules -a always,exit -F path=/usr/sbin/setfiles -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-priv_change If the command does not return any output, this is a finding.

Fix: F-4663r861022_fix

Configure the operating system to generate audit records when successful/unsuccessful attempts to use the "setfiles" command occur. Add or update the following rule in "/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-priv_change The audit daemon must be restarted for the changes to take effect.

b
The Red Hat Enterprise Linux operating system must generate audit records for all unsuccessful account access events.
AU-2 - Medium - CCI-000126 - V-204540 - SV-204540r853930_rule
RMF Control
AU-2
Severity
Medium
CCI
CCI-000126
Version
RHEL-07-030610
Vuln IDs
  • V-204540
  • V-72145
Rule IDs
  • SV-204540r853930_rule
  • SV-86769
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-000392-GPOS-00172, SRG-OS-000470-GPOS-00214, SRG-OS-000473-GPOS-00218
Checks: C-4664r88812_chk

Verify the operating system generates audit records when unsuccessful account access events occur. Check the file system rule in "/etc/audit/audit.rules" with the following commands: # grep -i /var/run/faillock /etc/audit/audit.rules -w /var/run/faillock -p wa -k logins If the command does not return any output, this is a finding.

Fix: F-4664r88813_fix

Configure the operating system to generate audit records when unsuccessful account access events occur. Add or update the following rule in "/etc/audit/rules.d/audit.rules": -w /var/run/faillock -p wa -k logins The audit daemon must be restarted for the changes to take effect.

b
The Red Hat Enterprise Linux operating system must generate audit records for all successful account access events.
AU-2 - Medium - CCI-000126 - V-204541 - SV-204541r853931_rule
RMF Control
AU-2
Severity
Medium
CCI
CCI-000126
Version
RHEL-07-030620
Vuln IDs
  • V-204541
  • V-72147
Rule IDs
  • SV-204541r853931_rule
  • SV-86771
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-000392-GPOS-00172, SRG-OS-000470-GPOS-00214, SRG-OS-000473-GPOS-00218
Checks: C-4665r88815_chk

Verify the operating system generates audit records when successful account access events occur. Check the file system rules in "/etc/audit/audit.rules" with the following commands: # grep -i /var/log/lastlog /etc/audit/audit.rules -w /var/log/lastlog -p wa -k logins If the command does not return any output, this is a finding.

Fix: F-4665r88816_fix

Configure the operating system to generate audit records when successful account access events occur. Add or update the following rule in "/etc/audit/rules.d/audit.rules": -w /var/log/lastlog -p wa -k logins The audit daemon must be restarted for the changes to take effect.

b
The Red Hat Enterprise Linux operating system must audit all uses of the passwd command.
AU-3 - Medium - CCI-000135 - V-204542 - SV-204542r861026_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000135
Version
RHEL-07-030630
Vuln IDs
  • V-204542
  • V-72149
Rule IDs
  • SV-204542r861026_rule
  • SV-86773
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 password commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. 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-000042-GPOS-00020, SRG-OS-000392-GPOS-00172, SRG-OS-000471-GPOS-00215
Checks: C-4666r861024_chk

Verify the operating system generates audit records when successful/unsuccessful attempts to use the "passwd" command occur. Check the file system rule in "/etc/audit/audit.rules" with the following command: $ sudo grep -w "/usr/bin/passwd" /etc/audit/audit.rules -a always,exit -F path=/usr/bin/passwd -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-passwd If the command does not return any output, this is a finding.

Fix: F-4666r861025_fix

Configure the operating system to generate audit records when successful/unsuccessful attempts to use the "passwd" command occur. Add or update the following rule in "/etc/audit/rules.d/audit.rules": -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.

b
The Red Hat Enterprise Linux operating system must audit all uses of the unix_chkpwd command.
AU-3 - Medium - CCI-000135 - V-204543 - SV-204543r861029_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000135
Version
RHEL-07-030640
Vuln IDs
  • V-204543
  • V-72151
Rule IDs
  • SV-204543r861029_rule
  • SV-86775
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 password commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. 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-000042-GPOS-00020, SRG-OS-000392-GPOS-00172, SRG-OS-000471-GPOS-00215
Checks: C-4667r861027_chk

Verify the operating system generates audit records when successful/unsuccessful attempts to use the "unix_chkpwd" command occur. Check the file system rule in "/etc/audit/audit.rules" with the following command: $ sudo grep -w "/usr/sbin/unix_chkpwd" /etc/audit/audit.rules -a always,exit -F path=/usr/sbin/unix_chkpwd -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-passwd If the command does not return any output, this is a finding.

Fix: F-4667r861028_fix

Configure the operating system to generate audit records when successful/unsuccessful attempts to use the "unix_chkpwd" command occur. Add or update the following rule in "/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-passwd The audit daemon must be restarted for the changes to take effect.

b
The Red Hat Enterprise Linux operating system must audit all uses of the gpasswd command.
AU-3 - Medium - CCI-000135 - V-204544 - SV-204544r861032_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000135
Version
RHEL-07-030650
Vuln IDs
  • V-204544
  • V-72153
Rule IDs
  • SV-204544r861032_rule
  • SV-86777
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 password commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. 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-000042-GPOS-00020, SRG-OS-000392-GPOS-00172, SRG-OS-000471-GPOS-00215
Checks: C-4668r861030_chk

Verify the operating system generates audit records when successful/unsuccessful attempts to use the "gpasswd" command occur. Check the file system rule in "/etc/audit/audit.rules" with the following command: $ sudo grep -w "/usr/bin/gpasswd" /etc/audit/audit.rules -a always,exit -F path=/usr/bin/gpasswd -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-passwd If the command does not return any output, this is a finding.

Fix: F-4668r861031_fix

Configure the operating system to generate audit records when successful/unsuccessful attempts to use the "gpasswd" command occur. Add or update the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/gpasswd -F perm=x -F auid>=1000 -F auid!=unset -k privileged-passwd The audit daemon must be restarted for the changes to take effect.

b
The Red Hat Enterprise Linux operating system must audit all uses of the chage command.
AU-3 - Medium - CCI-000135 - V-204545 - SV-204545r861035_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000135
Version
RHEL-07-030660
Vuln IDs
  • V-204545
  • V-72155
Rule IDs
  • SV-204545r861035_rule
  • SV-86779
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 password commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. 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-000042-GPOS-00020, SRG-OS-000392-GPOS-00172, SRG-OS-000471-GPOS-00215
Checks: C-4669r861033_chk

Verify the operating system generates audit records when successful/unsuccessful attempts to use the "chage" command occur. Check the file system rule in "/etc/audit/audit.rules" with the following command: $ sudo grep -w "/usr/bin/chage" /etc/audit/audit.rules -a always,exit -F path=/usr/bin/chage -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-passwd If the command does not return any output, this is a finding.

Fix: F-4669r861034_fix

Configure the operating system to generate audit records when successful/unsuccessful attempts to use the "chage" command occur. Add or update the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/chage -F perm=x -F auid>=1000 -F auid!=unset -k privileged-passwd The audit daemon must be restarted for the changes to take effect.

b
The Red Hat Enterprise Linux operating system must audit all uses of the userhelper command.
AU-3 - Medium - CCI-000135 - V-204546 - SV-204546r861038_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000135
Version
RHEL-07-030670
Vuln IDs
  • V-204546
  • V-72157
Rule IDs
  • SV-204546r861038_rule
  • SV-86781
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 password commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. 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-000042-GPOS-00020, SRG-OS-000392-GPOS-00172, SRG-OS-000471-GPOS-00215
Checks: C-4670r861036_chk

Verify the operating system generates audit records when successful/unsuccessful attempts to use the "userhelper" command occur. Check the file system rule in "/etc/audit/audit.rules" with the following command: $ sudo grep -w "/usr/sbin/userhelper" /etc/audit/audit.rules -a always,exit -F path=/usr/sbin/userhelper -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-passwd If the command does not return any output, this is a finding.

Fix: F-4670r861037_fix

Configure the operating system to generate audit records when successful/unsuccessful attempts to use the "userhelper" command occur. Add or update the following rule in "/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-passwd The audit daemon must be restarted for the changes to take effect.

b
The Red Hat Enterprise Linux operating system must audit all uses of the su command.
AU-3 - Medium - CCI-000130 - V-204547 - SV-204547r861041_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
RHEL-07-030680
Vuln IDs
  • V-204547
  • V-72159
Rule IDs
  • SV-204547r861041_rule
  • SV-86783
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 access commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. 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-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
Checks: C-4671r861039_chk

Verify the operating system generates audit records when successful/unsuccessful attempts to use the "su" command occur. Check that the following system call is being audited by performing the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w "/usr/bin/su" /etc/audit/audit.rules -a always,exit -F path=/usr/bin/su -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-priv_change If the command does not return any output, this is a finding.

Fix: F-4671r861040_fix

Configure the operating system to generate audit records when successful/unsuccessful attempts to use the "su" command occur. Add or update 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.

b
The Red Hat Enterprise Linux operating system must audit all uses of the sudo command.
AU-3 - Medium - CCI-000130 - V-204548 - SV-204548r861044_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
RHEL-07-030690
Vuln IDs
  • V-204548
  • V-72161
Rule IDs
  • SV-204548r861044_rule
  • SV-86785
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 access commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. 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-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
Checks: C-4672r861042_chk

Verify the operating system generates audit records when successful/unsuccessful attempts to use the "sudo" command occur. Check that the following system call is being audited by performing the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w "/usr/bin/sudo" /etc/audit/audit.rules -a always,exit -F path=/usr/bin/sudo -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-priv_change If the command does not return any output, this is a finding.

Fix: F-4672r861043_fix

Configure the operating system to generate audit records when successful/unsuccessful attempts to use the "sudo" command occur. Add or update the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/sudo -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.

b
The Red Hat Enterprise Linux operating system must audit all uses of the sudoers file and all files in the /etc/sudoers.d/ directory.
AU-3 - Medium - CCI-000130 - V-204549 - SV-204549r853953_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
RHEL-07-030700
Vuln IDs
  • V-204549
  • V-72163
Rule IDs
  • SV-204549r853953_rule
  • SV-86787
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 access commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
Checks: C-4673r88839_chk

Verify the operating system generates audit records when successful/unsuccessful attempts to access the "/etc/sudoers" file and files in the "/etc/sudoers.d/" directory. Check for modification of the following files being audited by performing the following commands to check the file system rules in "/etc/audit/audit.rules": # grep -i "/etc/sudoers" /etc/audit/audit.rules -w /etc/sudoers -p wa -k privileged-actions # grep -i "/etc/sudoers.d/" /etc/audit/audit.rules -w /etc/sudoers.d/ -p wa -k privileged-actions If the commands do not return output that match the examples, this is a finding.

Fix: F-4673r88840_fix

Configure the operating system to generate audit records when successful/unsuccessful attempts to access the "/etc/sudoers" file and files in the "/etc/sudoers.d/" directory. Add or update the following rule in "/etc/audit/rules.d/audit.rules": -w /etc/sudoers -p wa -k privileged-actions -w /etc/sudoers.d/ -p wa -k privileged-actions The audit daemon must be restarted for the changes to take effect.

b
The Red Hat Enterprise Linux operating system must audit all uses of the newgrp command.
AU-3 - Medium - CCI-000130 - V-204550 - SV-204550r861047_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
RHEL-07-030710
Vuln IDs
  • V-204550
  • V-72165
Rule IDs
  • SV-204550r861047_rule
  • SV-86789
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 access commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. 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-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
Checks: C-4674r861045_chk

Verify the operating system generates audit records when successful/unsuccessful attempts to use the "newgrp" command occur. Check that the following system call is being audited by performing the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w "/usr/bin/newgrp" /etc/audit/audit.rules -a always,exit -F path=/usr/bin/newgrp -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-priv_change If the command does not return any output, this is a finding.

Fix: F-4674r861046_fix

Configure the operating system to generate audit records when successful/unsuccessful attempts to use the "newgrp" command occur. Add or update the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/newgrp -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.

b
The Red Hat Enterprise Linux operating system must audit all uses of the chsh command.
AU-3 - Medium - CCI-000130 - V-204551 - SV-204551r861050_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000130
Version
RHEL-07-030720
Vuln IDs
  • V-204551
  • V-72167
Rule IDs
  • SV-204551r861050_rule
  • SV-86791
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 access commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. 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-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
Checks: C-4675r861048_chk

Verify the operating system generates audit records when successful/unsuccessful attempts to use the "chsh" command occur. Check that the following system call is being audited by performing the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w "/usr/bin/chsh" /etc/audit/audit.rules -a always,exit -F path=/usr/bin/chsh -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-priv_change If the command does not return any output, this is a finding.

Fix: F-4675r861049_fix

Configure the operating system to generate audit records when successful/unsuccessful attempts to use the "chsh" command occur. Add or update the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/chsh -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.

b
The Red Hat Enterprise Linux operating system must audit all uses of the mount command and syscall.
AU-3 - Medium - CCI-000135 - V-204552 - SV-204552r861053_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000135
Version
RHEL-07-030740
Vuln IDs
  • V-204552
  • V-72171
Rule IDs
  • SV-204552r861053_rule
  • SV-86795
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 mount commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. 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-000042-GPOS-00020, SRG-OS-000392-GPOS-00172
Checks: C-4676r861051_chk

Verify the operating system generates audit records when successful/unsuccessful attempts to use the "mount" command and syscall occur. Check that the following system call is being audited by performing the following series of commands to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w "mount" /etc/audit/audit.rules -a always,exit -F arch=b32 -S mount -F auid&gt;=1000 -F auid!=unset -k privileged-mount -a always,exit -F arch=b64 -S mount -F auid&gt;=1000 -F auid!=unset -k privileged-mount -a always,exit -F path=/usr/bin/mount -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-mount If both the "b32" and "b64" audit rules are not defined for the "mount" syscall, this is a finding. If all uses of the "mount" command are not being audited, this is a finding.

Fix: F-4676r861052_fix

Configure the operating system to generate audit records when successful/unsuccessful attempts to use the "mount" command and syscall occur. Add or update the following rules in "/etc/audit/rules.d/audit.rules": -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 -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.

b
The Red Hat Enterprise Linux operating system must audit all uses of the umount command.
AU-3 - Medium - CCI-000135 - V-204553 - SV-204553r861056_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000135
Version
RHEL-07-030750
Vuln IDs
  • V-204553
  • V-72173
Rule IDs
  • SV-204553r861056_rule
  • SV-86797
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 mount commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. 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-000042-GPOS-00020, SRG-OS-000392-GPOS-00172
Checks: C-4677r861054_chk

Verify the operating system generates audit records when successful/unsuccessful attempts to use the "umount" command occur. Check that the following system call is being audited by performing the following series of commands to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w "/usr/bin/umount" /etc/audit/audit.rules -a always,exit -F path=/usr/bin/umount -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-mount If the command does not return any output, this is a finding.

Fix: F-4677r861055_fix

Configure the operating system to generate audit records when successful/unsuccessful attempts to use the "umount" command occur. Add or update the following rule in "/etc/audit/rules.d/audit.rules": -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.

b
The Red Hat Enterprise Linux operating system must audit all uses of the postdrop command.
AU-3 - Medium - CCI-000135 - V-204554 - SV-204554r861059_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000135
Version
RHEL-07-030760
Vuln IDs
  • V-204554
  • V-72175
Rule IDs
  • SV-204554r861059_rule
  • SV-86799
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 postfix commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. 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-000042-GPOS-00020, SRG-OS-000392-GPOS-00172
Checks: C-4678r861057_chk

Verify the operating system generates audit records when successful/unsuccessful attempts to use the "postdrop" command occur. Check that the following system call is being audited by performing the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w "/usr/sbin/postdrop" /etc/audit/audit.rules -a always,exit -F path=/usr/sbin/postdrop -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-postfix If the command does not return any output, this is a finding.

Fix: F-4678r861058_fix

Configure the operating system to generate audit records when successful/unsuccessful attempts to use the "postdrop" command occur. Add or update the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/sbin/postdrop -F perm=x -F auid>=1000 -F auid!=unset -k privileged-postfix The audit daemon must be restarted for the changes to take effect.

b
The Red Hat Enterprise Linux operating system must audit all uses of the postqueue command.
AU-3 - Medium - CCI-000135 - V-204555 - SV-204555r861062_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000135
Version
RHEL-07-030770
Vuln IDs
  • V-204555
  • V-72177
Rule IDs
  • SV-204555r861062_rule
  • SV-86801
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 postfix commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. 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-000042-GPOS-00020, SRG-OS-000392-GPOS-00172
Checks: C-4679r861060_chk

Verify the operating system generates audit records when successful/unsuccessful attempts to use the "postqueue" command occur. Check that the following system call is being audited by performing the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w "/usr/sbin/postqueue" /etc/audit/audit.rules -a always,exit -F path=/usr/sbin/postqueue -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-postfix If the command does not return any output, this is a finding.

Fix: F-4679r861061_fix

Configure the operating system to generate audit records when successful/unsuccessful attempts to use the "postqueue" command occur. Add or update the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/sbin/postqueue -F perm=x -F auid>=1000 -F auid!=unset -k privileged-postfix The audit daemon must be restarted for the changes to take effect.

b
The Red Hat Enterprise Linux operating system must audit all uses of the ssh-keysign command.
AU-3 - Medium - CCI-000135 - V-204556 - SV-204556r861065_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000135
Version
RHEL-07-030780
Vuln IDs
  • V-204556
  • V-72179
Rule IDs
  • SV-204556r861065_rule
  • SV-86803
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 ssh commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. 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-000042-GPOS-00020, SRG-OS-000392-GPOS-00172, SRG-OS-000471-GPOS-00215
Checks: C-4680r861063_chk

Verify the operating system generates audit records when successful/unsuccessful attempts to use the "ssh-keysign" command occur. Check that the following system call is being audited by performing the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w "/usr/libexec/openssh/ssh-keysign" /etc/audit/audit.rules -a always,exit -F path=/usr/libexec/openssh/ssh-keysign -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-ssh If the command does not return any output, this is a finding.

Fix: F-4680r861064_fix

Configure the operating system to generate audit records when successful/unsuccessful attempts to use the "ssh-keysign" command occur. Add or update the following rule in "/etc/audit/rules.d/audit.rules": -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.

b
The Red Hat Enterprise Linux operating system must audit all uses of the crontab command.
AU-3 - Medium - CCI-000135 - V-204557 - SV-204557r861068_rule
RMF Control
AU-3
Severity
Medium
CCI
CCI-000135
Version
RHEL-07-030800
Vuln IDs
  • V-204557
  • V-72183
Rule IDs
  • SV-204557r861068_rule
  • SV-86807
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. 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-000042-GPOS-00020, SRG-OS-000392-GPOS-00172, SRG-OS-000471-GPOS-00215
Checks: C-4681r861066_chk

Verify the operating system generates audit records when successful/unsuccessful attempts to use the "crontab" command occur. Check that the following system call is being audited by performing the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -w "/usr/bin/crontab" /etc/audit/audit.rules -a always,exit -F path=/usr/bin/crontab -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-cron If the command does not return any output, this is a finding.

Fix: F-4681r861067_fix

Configure the operating system to generate audit records when successful/unsuccessful attempts to use the "crontab" command occur. Add or update the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/crontab -F perm=x -F auid>=1000 -F auid!=unset -k privileged-cron The audit daemon must be restarted for the changes to take effect.

b
The Red Hat Enterprise Linux operating system must audit all uses of the pam_timestamp_check command.
AU-12 - Medium - CCI-000172 - V-204558 - SV-204558r833166_rule
RMF Control
AU-12
Severity
Medium
CCI
CCI-000172
Version
RHEL-07-030810
Vuln IDs
  • V-204558
  • V-72185
Rule IDs
  • SV-204558r833166_rule
  • SV-86809
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. When a user logs on, the auid is set to the uid of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way.
Checks: C-4682r833164_chk

Verify the operating system generates audit records when successful/unsuccessful attempts to use the "pam_timestamp_check" command occur. Check the auditing rules in "/etc/audit/audit.rules" with the following command: $ sudo grep -w "/usr/sbin/pam_timestamp_check" /etc/audit/audit.rules -a always,exit -F path=/usr/sbin/pam_timestamp_check -F perm=x -F auid&gt;=1000 -F auid!=unset -k privileged-pam If the command does not return any output, this is a finding.

Fix: F-4682r833165_fix

Configure the operating system to generate audit records when successful/unsuccessful attempts to use the "pam_timestamp_check" command occur. Add or update the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/sbin/pam_timestamp_check -F perm=x -F auid>=1000 -F auid!=unset -k privileged-pam The audit daemon must be restarted for the changes to take effect.

b
The Red Hat Enterprise Linux operating system must audit all uses of the create_module syscall.
AU-12 - Medium - CCI-000172 - V-204559 - SV-204559r833169_rule
RMF Control
AU-12
Severity
Medium
CCI
CCI-000172
Version
RHEL-07-030819
Vuln IDs
  • V-204559
  • V-78999
Rule IDs
  • SV-204559r833169_rule
  • SV-93705
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-000471-GPOS-00216, SRG-OS-000477-GPOS-00222
Checks: C-4683r833167_chk

Verify the operating system generates audit records when successful/unsuccessful attempts to use the "create_module" syscall occur. Check the auditing rules in "/etc/audit/audit.rules" with the following command: $ sudo grep -w "create_module" /etc/audit/audit.rules -a always,exit -F arch=b32 -S create_module -F auid&gt;=1000 -F auid!=unset -k module-change -a always,exit -F arch=b64 -S create_module -F auid&gt;=1000 -F auid!=unset -k module-change If both the "b32" and "b64" audit rules are not defined for the "create_module" syscall, this is a finding.

Fix: F-4683r833168_fix

Configure the operating system to generate audit records when successful/unsuccessful attempts to use the "create_module" syscall occur. Add or update the following rules in "/etc/audit/rules.d/audit.rules": -a always,exit -F arch=b32 -S create_module -F auid>=1000 -F auid!=unset -k module-change -a always,exit -F arch=b64 -S create_module -F auid>=1000 -F auid!=unset -k module-change The audit daemon must be restarted for the changes to take effect.

b
The Red Hat Enterprise Linux operating system must audit all uses of the init_module and finit_module syscalls.
AU-12 - Medium - CCI-000172 - V-204560 - SV-204560r833172_rule
RMF Control
AU-12
Severity
Medium
CCI
CCI-000172
Version
RHEL-07-030820
Vuln IDs
  • V-204560
  • V-72187
Rule IDs
  • SV-204560r833172_rule
  • SV-86811
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 system call rules are loaded into a matching engine that intercepts each syscall made by all programs on the system. Therefore, it is very important to use syscall rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining syscalls into one rule whenever possible. Satisfies: SRG-OS-000471-GPOS-00216, SRG-OS-000477-GPOS-00222
Checks: C-4684r833170_chk

Verify the operating system generates audit records upon successful/unsuccessful attempts to use the "init_module" and "finit_module" syscalls. Check the auditing rules in "/etc/audit/audit.rules" with the following command: $ sudo grep init_module /etc/audit/audit.rules -a always,exit -F arch=b32 -S init_module,finit_module -F auid&gt;=1000 -F auid!=unset -k modulechange -a always,exit -F arch=b64 -S init_module,finit_module -F auid&gt;=1000 -F auid!=unset -k modulechange If both the "b32" and "b64" audit rules are not defined for the "init_module" and "finit_module" syscalls, this is a finding.

Fix: F-4684r833171_fix

Configure the operating system to generate audit records upon successful/unsuccessful attempts to use the "init_module" and "finit_module" syscalls. Add or update the following rules in "/etc/audit/rules.d/audit.rules": -a always,exit -F arch=b32 -S init_module,finit_module -F auid>=1000 -F auid!=unset -k modulechange -a always,exit -F arch=b64 -S init_module,finit_module -F auid>=1000 -F auid!=unset -k modulechange The audit daemon must be restarted for the changes to take effect.

b
The Red Hat Enterprise Linux operating system must audit all uses of the delete_module syscall.
AU-12 - Medium - CCI-000172 - V-204562 - SV-204562r833175_rule
RMF Control
AU-12
Severity
Medium
CCI
CCI-000172
Version
RHEL-07-030830
Vuln IDs
  • V-204562
  • V-72189
Rule IDs
  • SV-204562r833175_rule
  • SV-86813
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-000471-GPOS-00216, SRG-OS-000477-GPOS-00222
Checks: C-4686r833173_chk

Verify the operating system generates audit records when successful/unsuccessful attempts to use the "delete_module" syscall occur. Check the auditing rules in "/etc/audit/audit.rules" with the following command: $ sudo grep -w "delete_module" /etc/audit/audit.rules -a always,exit -F arch=b32 -S delete_module -F auid&gt;=1000 -F auid!=unset -k module-change -a always,exit -F arch=b64 -S delete_module -F auid&gt;=1000 -F auid!=unset -k module-change If both the "b32" and "b64" audit rules are not defined for the "delete_module" syscall, this is a finding.

Fix: F-4686r833174_fix

Configure the operating system to generate audit records when successful/unsuccessful attempts to use the "delete_module" syscall occur. Add or update the following rules in "/etc/audit/rules.d/audit.rules": -a always,exit -F arch=b32 -S delete_module -F auid>=1000 -F auid!=unset -k module-change -a always,exit -F arch=b64 -S delete_module -F auid>=1000 -F auid!=unset -k module-change The audit daemon must be restarted for the changes to take effect.

b
The Red Hat Enterprise Linux operating system must audit all uses of the kmod command.
AU-12 - Medium - CCI-000172 - V-204563 - SV-204563r858498_rule
RMF Control
AU-12
Severity
Medium
CCI
CCI-000172
Version
RHEL-07-030840
Vuln IDs
  • V-204563
  • V-72191
Rule IDs
  • SV-204563r858498_rule
  • SV-86815
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). 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-000471-GPOS-00216, SRG-OS-000477-GPOS-00222
Checks: C-4687r858496_chk

Verify the operating system generates audit records when successful/unsuccessful attempts to use the "kmod" command occur. Check the auditing rules in "/etc/audit/audit.rules" with the following command: $ sudo grep "/usr/bin/kmod" /etc/audit/audit.rules -a always,exit -F path=/usr/bin/kmod -F perm=x -F auid&gt;=1000 -F auid!=unset -k modules If the command does not return any output, this is a finding.

Fix: F-4687r858497_fix

Configure the operating system to generate audit records when successful/unsuccessful attempts to use the "kmod" command occur. Add or update the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/kmod -F perm=x -F auid>=1000 -F auid!=unset -k modules The audit daemon must be restarted for the changes to take effect.

b
The Red Hat Enterprise Linux operating system must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/passwd.
AC-2 - Medium - CCI-000018 - V-204564 - SV-204564r853978_rule
RMF Control
AC-2
Severity
Medium
CCI
CCI-000018
Version
RHEL-07-030870
Vuln IDs
  • V-204564
  • V-72197
Rule IDs
  • SV-204564r853978_rule
  • SV-86821
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-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000476-GPOS-00221
Checks: C-4688r88884_chk

Verify the operating system must generate audit records for all account creations, modifications, disabling, and termination events that affect "/etc/passwd". Check the auditing rules in "/etc/audit/audit.rules" with the following command: # grep /etc/passwd /etc/audit/audit.rules -w /etc/passwd -p wa -k identity If the command does not return a line, or the line is commented out, this is a finding.

Fix: F-4688r88885_fix

Configure the operating system to generate audit records for all account creations, modifications, disabling, and termination events that affect "/etc/passwd". Add or update the following rule "/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.

b
The Red Hat Enterprise Linux operating system must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/group.
AC-2 - Medium - CCI-000018 - V-204565 - SV-204565r853979_rule
RMF Control
AC-2
Severity
Medium
CCI
CCI-000018
Version
RHEL-07-030871
Vuln IDs
  • V-204565
  • V-73165
Rule IDs
  • SV-204565r853979_rule
  • SV-87817
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter).
Checks: C-4689r88887_chk

Verify the operating system must generate audit records for all account creations, modifications, disabling, and termination events that affect "/etc/group". Check the auditing rules in "/etc/audit/audit.rules" with the following command: # grep /etc/group /etc/audit/audit.rules -w /etc/group -p wa -k identity If the command does not return a line, or the line is commented out, this is a finding.

Fix: F-4689r88888_fix

Configure the operating system to generate audit records for all account creations, modifications, disabling, and termination events that affect "/etc/group". Add or update the following rule in "/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.

b
The Red Hat Enterprise Linux operating system must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/gshadow.
AC-2 - Medium - CCI-000018 - V-204566 - SV-204566r853980_rule
RMF Control
AC-2
Severity
Medium
CCI
CCI-000018
Version
RHEL-07-030872
Vuln IDs
  • V-204566
  • V-73167
Rule IDs
  • SV-204566r853980_rule
  • SV-87819
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter).
Checks: C-4690r88890_chk

Verify the operating system must generate audit records for all account creations, modifications, disabling, and termination events that affect "/etc/gshadow". Check the auditing rules in "/etc/audit/audit.rules" with the following command: # grep /etc/gshadow /etc/audit/audit.rules -w /etc/gshadow -p wa -k identity If the command does not return a line, or the line is commented out, this is a finding.

Fix: F-4690r88891_fix

Configure the operating system to generate audit records for all account creations, modifications, disabling, and termination events that affect "/etc/gshadow". Add or update the following rule in "/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.

b
The Red Hat Enterprise Linux operating system must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/shadow.
AC-2 - Medium - CCI-000018 - V-204567 - SV-204567r853981_rule
RMF Control
AC-2
Severity
Medium
CCI
CCI-000018
Version
RHEL-07-030873
Vuln IDs
  • V-204567
  • V-73171
Rule IDs
  • SV-204567r853981_rule
  • SV-87823
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter).
Checks: C-4691r88893_chk

Verify the operating system must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/shadow. Check the auditing rules in "/etc/audit/audit.rules" with the following command: # grep /etc/shadow /etc/audit/audit.rules -w /etc/shadow -p wa -k identity If the command does not return a line, or the line is commented out, this is a finding.

Fix: F-4691r88894_fix

Configure the operating system to generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/shadow. Add or update the following file system rule in "/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.

b
The Red Hat Enterprise Linux operating system must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/security/opasswd.
AC-2 - Medium - CCI-000018 - V-204568 - SV-204568r853982_rule
RMF Control
AC-2
Severity
Medium
CCI
CCI-000018
Version
RHEL-07-030874
Vuln IDs
  • V-204568
  • V-73173
Rule IDs
  • SV-204568r853982_rule
  • SV-87825
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter).
Checks: C-4692r744113_chk

Verify the operating system must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/security/opasswd. Check the auditing rules in "/etc/audit/audit.rules" with the following command: # grep /etc/security/opasswd /etc/audit/audit.rules -w /etc/security/opasswd -p wa -k identity If the command does not return a line, or the line is commented out, this is a finding.

Fix: F-4692r744114_fix

Configure the operating system to generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/security/opasswd. Add or update the following file system rule in "/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: # systemctl restart auditd

b
The Red Hat Enterprise Linux operating system must audit all uses of the unlink, unlinkat, rename, renameat, and rmdir syscalls.
AU-12 - Medium - CCI-000172 - V-204572 - SV-204572r853985_rule
RMF Control
AU-12
Severity
Medium
CCI
CCI-000172
Version
RHEL-07-030910
Vuln IDs
  • V-204572
  • V-72205
Rule IDs
  • SV-204572r853985_rule
  • SV-86829
If the system is not configured to audit certain activities and write them to an audit log, it is more difficult to detect and track system compromises and damages incurred during a system compromise. 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 made by all programs on the system. Therefore, it is very important to use syscall rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining syscalls into one rule whenever possible. Satisfies: SRG-OS-000466-GPOS-00210, SRG-OS-000467-GPOS-00211, SRG-OS-000468-GPOS-00212, SRG-OS-000392-GPOS-00172
Checks: C-4696r853983_chk

Verify the operating system generates audit records upon successful/unsuccessful attempts to use the "unlink", "unlinkat", "rename", "renameat", and "rmdir" syscalls. Check the file system rules in "/etc/audit/audit.rules" with the following commands: # grep 'unlink\|rename\|rmdir' /etc/audit/audit.rules -a always,exit -F arch=b32 -S unlink,unlinkat,rename,renameat,rmdir -F auid&gt;=1000 -F auid!=unset -k delete -a always,exit -F arch=b64 -S unlink,unlinkat,rename,renameat,rmdir -F auid&gt;=1000 -F auid!=unset -k delete If both the "b32" and "b64" audit rules are not defined for the "unlink", "unlinkat", "rename", "renameat", and "rmdir" syscalls, this is a finding.

Fix: F-4696r853984_fix

Configure the operating system to generate audit records upon successful/unsuccessful attempts to use the "unlink", "unlinkat", "rename", "renameat", and "rmdir" syscalls. Add the following rules in "/etc/audit/rules.d/audit.rules": -a always,exit -F arch=b32 -S unlink,unlinkat,rename,renameat,rmdir -F auid>=1000 -F auid!=unset -k delete -a always,exit -F arch=b64 -S unlink,unlinkat,rename,renameat,rmdir -F auid>=1000 -F auid!=unset -k delete The audit daemon must be restarted for the changes to take effect.

b
The Red Hat Enterprise Linux operating system must send rsyslog output to a log aggregation server.
CM-6 - Medium - CCI-000366 - V-204574 - SV-204574r917830_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-031000
Vuln IDs
  • V-204574
  • V-72209
Rule IDs
  • SV-204574r917830_rule
  • SV-86833
Sending rsyslog output to another system ensures that the logs cannot be removed or modified in the event that the system is compromised or has a hardware failure.
Checks: C-4698r917828_chk

Verify "rsyslog" is configured to send all messages to a log aggregation server. Check the configuration of "rsyslog" with the following command: Note: If another logging package is used, substitute the utility configuration file for "/etc/rsyslog.conf". # grep @ /etc/rsyslog.conf /etc/rsyslog.d/*.conf *.* @@[logaggregationserver.example.mil]:[port] If there are no lines in the "/etc/rsyslog.conf" or "/etc/rsyslog.d/*.conf" files that contain the "@" or "@@" symbol(s), and the lines with the correct symbol(s) to send output to another system do not cover all "rsyslog" output, ask the system administrator to indicate how the audit logs are offloaded to a different system or media. If the lines are commented out or there is no evidence that the audit logs are being sent to another log aggregation server, this is a finding.

Fix: F-4698r917829_fix

Modify the "/etc/rsyslog.conf" or an "/etc/rsyslog.d/*.conf" file to contain a configuration line to send all "rsyslog" output to a log aggregation server: For UDP: *.* @[logaggregationserver.example.mil]:[port] For TCP: *.* @@[logaggregationserver.example.mil]:[port]

b
The Red Hat Enterprise Linux operating system must be configured so that the rsyslog daemon does not accept log messages from other servers unless the server is being used for log aggregation.
CM-3 - Medium - CCI-000318 - V-204575 - SV-204575r853986_rule
RMF Control
CM-3
Severity
Medium
CCI
CCI-000318
Version
RHEL-07-031010
Vuln IDs
  • V-204575
  • V-72211
Rule IDs
  • SV-204575r853986_rule
  • SV-86835
Unintentionally running a rsyslog server accepting remote messages puts the system at increased risk. Malicious rsyslog messages sent to the server could exploit vulnerabilities in the server software itself, could introduce misleading information in to the system's logs, or could fill the system's storage leading to a Denial of Service. If the system is intended to be a log aggregation server its use must be documented with the ISSO.
Checks: C-4699r88917_chk

Verify that the system is not accepting "rsyslog" messages from other systems unless it is documented as a log aggregation server. Check the configuration of "rsyslog" with the following command: # grep imtcp /etc/rsyslog.conf $ModLoad imtcp # grep imudp /etc/rsyslog.conf $ModLoad imudp # grep imrelp /etc/rsyslog.conf $ModLoad imrelp If any of the above modules are being loaded in the "/etc/rsyslog.conf" file, ask to see the documentation for the system being used for log aggregation. If the documentation does not exist, or does not specify the server as a log aggregation system, this is a finding.

Fix: F-4699r88918_fix

Modify the "/etc/rsyslog.conf" file to remove the "ModLoad imtcp", "ModLoad imudp", and "ModLoad imrelp" configuration lines, or document the system as being used for log aggregation.

a
The Red Hat Enterprise Linux operating system must limit the number of concurrent sessions to 10 for all accounts and/or account types.
AC-10 - Low - CCI-000054 - V-204576 - SV-204576r877399_rule
RMF Control
AC-10
Severity
Low
CCI
CCI-000054
Version
RHEL-07-040000
Vuln IDs
  • V-204576
  • V-72217
Rule IDs
  • SV-204576r877399_rule
  • SV-86841
Operating system management includes the ability to control the number of users and user sessions that utilize an operating system. Limiting the number of allowed users and sessions per user is helpful in reducing the risks related to DoS attacks. This requirement addresses concurrent sessions for information system accounts and does not address concurrent sessions by single users via multiple system accounts. The maximum number of concurrent sessions should be defined based on mission needs and the operational environment for each system.
Checks: C-4700r88920_chk

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

Fix: F-4700r88921_fix

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

b
The Red Hat Enterprise Linux operating system must be configured to prohibit or restrict the use of functions, ports, protocols, and/or services, as defined in the Ports, Protocols, and Services Management Component Local Service Assessment (PPSM CLSA) and vulnerability assessments.
CM-7 - Medium - CCI-000382 - V-204577 - SV-204577r861069_rule
RMF Control
CM-7
Severity
Medium
CCI
CCI-000382
Version
RHEL-07-040100
Vuln IDs
  • V-204577
  • V-72219
Rule IDs
  • SV-204577r861069_rule
  • SV-86843
In order to prevent unauthorized connection of devices, unauthorized transfer of information, or unauthorized tunneling (i.e., embedding of data types within data types), organizations must disable or restrict unused or unnecessary physical and logical ports/protocols on information systems. Operating systems are capable of providing a wide variety of functions and services. Some of the functions and services provided by default may not be necessary to support essential organizational operations. Additionally, it is sometimes convenient to provide multiple services from a single component (e.g., VPN and IPS); however, doing so increases risk over limiting the services provided by any one component. To support the requirements and principles of least functionality, the operating system must support the organizational requirements, providing only essential capabilities and limiting the use of ports, protocols, and/or services to only those required, authorized, and approved to conduct official business or to address authorized quality of life issues. Satisfies: SRG-OS-000096-GPOS-00050, SRG-OS-000297-GPOS-00115
Checks: C-4701r88923_chk

Inspect the firewall configuration and running services to verify that it is configured to prohibit or restrict the use of functions, ports, protocols, and/or services that are unnecessary or prohibited. Check which services are currently active with the following command: # firewall-cmd --list-all public (default, active) interfaces: enp0s3 sources: services: dhcpv6-client dns http https ldaps rpc-bind ssh ports: masquerade: no forward-ports: icmp-blocks: rich rules: Ask the System Administrator for the site or program PPSM CLSA. Verify the services allowed by the firewall match the PPSM CLSA. If there are additional ports, protocols, or services that are not in the PPSM CLSA, or there are ports, protocols, or services that are prohibited by the PPSM Category Assurance List (CAL), this is a finding.

Fix: F-4701r88924_fix

Update the host's firewall settings and/or running services to comply with the PPSM CLSA for the site or program and the PPSM CAL.

b
The Red Hat Enterprise Linux 7 operating system must implement DoD-approved encryption to protect the confidentiality of SSH connections.
AC-17 - Medium - CCI-000068 - V-204578 - SV-204578r877398_rule
RMF Control
AC-17
Severity
Medium
CCI
CCI-000068
Version
RHEL-07-040110
Vuln IDs
  • V-204578
  • V-72221
Rule IDs
  • SV-204578r877398_rule
  • SV-86845
Unapproved mechanisms that are used for authentication to the cryptographic module are not verified and therefore cannot be relied upon to provide confidentiality or integrity, and DoD data may be compromised. Operating systems utilizing 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 utilize authentication that meets DoD requirements. This allows for Security Levels 1, 2, 3, or 4 for use on a general purpose computing system. The system will attempt to use the first cipher presented by the client that matches the server list. Listing the values "strongest to weakest" is a method to ensure the use of the strongest cipher available to secure the SSH connection. Satisfies: SRG-OS-000033-GPOS-00014, SRG-OS-000120-GPOS-00061, SRG-OS-000125-GPOS-00065, SRG-OS-000250-GPOS-00093, SRG-OS-000393-GPOS-00173
Checks: C-4702r622305_chk

Verify the operating system uses mechanisms meeting the requirements of applicable federal laws, Executive orders, directives, policies, regulations, standards, and guidance for authentication to a cryptographic module. The location of the "sshd_config" file may vary if a different daemon is in use. Inspect the "Ciphers" configuration with the following command: # grep -i ciphers /etc/ssh/sshd_config Ciphers aes256-ctr,aes192-ctr,aes128-ctr If any ciphers other than "aes256-ctr", "aes192-ctr", or "aes128-ctr" are listed, the order differs from the example above, the "Ciphers" keyword is missing, or the returned line is commented out, this is a finding.

Fix: F-4702r622306_fix

Configure SSH to use FIPS 140-2 approved cryptographic algorithms. Add the following line (or modify the line to have the required value) to the "/etc/ssh/sshd_config" file (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). Ciphers aes256-ctr,aes192-ctr,aes128-ctr The SSH service must be restarted for changes to take effect.

b
The Red Hat Enterprise Linux operating system must be configured so that all network connections associated with a communication session are terminated at the end of the session or after 15 minutes of inactivity from the user at a command prompt, except to fulfill documented and validated mission requirements.
SC-10 - Medium - CCI-001133 - V-204579 - SV-204579r861070_rule
RMF Control
SC-10
Severity
Medium
CCI
CCI-001133
Version
RHEL-07-040160
Vuln IDs
  • V-204579
  • V-72223
Rule IDs
  • SV-204579r861070_rule
  • SV-86847
Terminating an idle session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been left unattended. In addition, quickly terminating an idle session will also free up resources committed by the managed network element. Terminating network connections associated with communications sessions includes, for example, de-allocating associated TCP/IP address/port pairs at the operating system level and de-allocating networking assignments at the application level if multiple application sessions are using a single operating system-level network connection. This does not mean that the operating system terminates all sessions or network access; it only ends the inactive session and releases the resources associated with that session. Satisfies: SRG-OS-000029-GPOS-00010, SRG-OS-000163-GPOS-00072
Checks: C-4703r858485_chk

Verify the operating system terminates all network connections associated with a communications session at the end of the session or based on inactivity. Check the value of the system inactivity timeout with the following command: $ sudo grep -irw tmout /etc/profile /etc/bashrc /etc/profile.d etc/profile.d/tmout.sh:declare -xr TMOUT=900 If conflicting results are returned, this is a finding. If "TMOUT" is not set to "900" or less to enforce session termination after inactivity, this is a finding.

Fix: F-4703r646843_fix

Configure the operating system to terminate all network connections associated with a communications session at the end of the session or after a period of inactivity. Create a script to enforce the inactivity timeout (for example /etc/profile.d/tmout.sh) such as: #!/bin/bash declare -xr TMOUT=900

b
The Red Hat Enterprise Linux operating system must display the Standard Mandatory DoD Notice and Consent Banner immediately prior to, or as part of, remote access logon prompts.
AC-8 - Medium - CCI-000048 - V-204580 - SV-204580r603261_rule
RMF Control
AC-8
Severity
Medium
CCI
CCI-000048
Version
RHEL-07-040170
Vuln IDs
  • V-204580
  • V-72225
Rule IDs
  • SV-204580r603261_rule
  • SV-86849
Display of a standardized and approved use notification before granting access to the publicly accessible operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. System use notifications are required only for access via logon interfaces with human users and are not required when such human interfaces do not exist. The banner must be formatted in accordance with applicable DoD policy. Use the following verbiage for operating systems that can accommodate banners of 1300 characters: "You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details." Satisfies: SRG-OS-000023-GPOS-00006, SRG-OS-000024-GPOS-00007 , SRG-OS-000228-GPOS-00088
Checks: C-4704r297485_chk

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

Fix: F-4704r297486_fix

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

b
The Red Hat Enterprise Linux operating system must implement cryptography to protect the integrity of Lightweight Directory Access Protocol (LDAP) authentication communications.
AC-17 - Medium - CCI-001453 - V-204581 - SV-204581r942906_rule
RMF Control
AC-17
Severity
Medium
CCI
CCI-001453
Version
RHEL-07-040180
Vuln IDs
  • V-204581
  • V-72227
Rule IDs
  • SV-204581r942906_rule
  • SV-86851
Without cryptographic integrity protections, information can be altered by unauthorized users without detection. 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 key used to generate the hash.
Checks: C-4705r942904_chk

If LDAP is not being utilized, this requirement is Not Applicable. Verify the operating system implements cryptography to protect the integrity of remote LDAP authentication sessions. To determine if LDAP is being used for authentication, use the following command: # systemctl status sssd.service sssd.service - System Security Services Daemon Loaded: loaded (/usr/lib/systemd/system/sssd.service; enabled; vendor preset: disabled) Active: active (running) since Wed 2018-06-27 10:58:11 EST; 1h 50min ago If the "sssd.service" is "active", then LDAP is being used. Determine the "id_provider" the LDAP is currently using: # grep -ir id_provider /etc/sssd/sssd.conf /etc/sssd/conf.d/*.conf id_provider = ad If "id_provider" is set to "ad", this is Not Applicable. Ensure that LDAP is configured to use TLS by using the following command: # grep -ir start_tls /etc/sssd/sssd.conf /etc/sssd/conf.d/*.conf ldap_id_use_start_tls = true If the "ldap_id_use_start_tls" option is not "true", this is a finding.

Fix: F-4705r942905_fix

Configure the operating system to implement cryptography to protect the integrity of LDAP authentication sessions. Add or modify the following line in "/etc/sssd/sssd.conf": ldap_id_use_start_tls = true

b
The Red Hat Enterprise Linux operating system must implement cryptography to protect the integrity of Lightweight Directory Access Protocol (LDAP) communications.
AC-17 - Medium - CCI-001453 - V-204582 - SV-204582r942909_rule
RMF Control
AC-17
Severity
Medium
CCI
CCI-001453
Version
RHEL-07-040190
Vuln IDs
  • V-204582
  • V-72229
Rule IDs
  • SV-204582r942909_rule
  • SV-86853
Without cryptographic integrity protections, information can be altered by unauthorized users without detection. 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 key used to generate the hash.
Checks: C-4706r942907_chk

If LDAP is not being utilized, this requirement is Not Applicable. Verify the operating system implements cryptography to protect the integrity of remote LDAP access sessions. To determine if LDAP is being used for authentication, use the following command: # systemctl status sssd.service sssd.service - System Security Services Daemon Loaded: loaded (/usr/lib/systemd/system/sssd.service; enabled; vendor preset: disabled) Active: active (running) since Wed 2018-06-27 10:58:11 EST; 1h 50min ago If the "sssd.service" is "active", then LDAP is being used. Determine the "id_provider" the LDAP is currently using: # grep -ir id_provider /etc/sssd/sssd.conf /etc/sssd/conf.d/*.conf id_provider = ad If "id_provider" is set to "ad", this is Not Applicable. Verify the sssd service is configured to require the use of certificates: # grep -ir tls_reqcert /etc/sssd/sssd.conf /etc/sssd/conf.d/*.conf ldap_tls_reqcert = demand If the "ldap_tls_reqcert" setting is missing, commented out, or does not exist, this is a finding. If the "ldap_tls_reqcert" setting is not set to "demand" or "hard", this is a finding.

Fix: F-4706r942908_fix

Configure the operating system to implement cryptography to protect the integrity of LDAP remote access sessions. Add or modify the following line in "/etc/sssd/sssd.conf": ldap_tls_reqcert = demand

b
The Red Hat Enterprise Linux operating system must implement cryptography to protect the integrity of Lightweight Directory Access Protocol (LDAP) communications.
AC-17 - Medium - CCI-001453 - V-204583 - SV-204583r942912_rule
RMF Control
AC-17
Severity
Medium
CCI
CCI-001453
Version
RHEL-07-040200
Vuln IDs
  • V-204583
  • V-72231
Rule IDs
  • SV-204583r942912_rule
  • SV-86855
Without cryptographic integrity protections, information can be altered by unauthorized users without detection. 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 key used to generate the hash.
Checks: C-4707r942910_chk

If LDAP is not being utilized, this requirement is Not Applicable. Verify the operating system implements cryptography to protect the integrity of remote LDAP access sessions. To determine if LDAP is being used for authentication, use the following command: # systemctl status sssd.service sssd.service - System Security Services Daemon Loaded: loaded (/usr/lib/systemd/system/sssd.service; enabled; vendor preset: disabled) Active: active (running) since Wed 2018-06-27 10:58:11 EST; 1h 50min ago If the "sssd.service" is "active", then LDAP is being used. Determine the "id_provider" that the LDAP is currently using: # grep -ir id_provider /etc/sssd/sssd.conf /etc/sssd/conf.d/*.conf id_provider = ad If "id_provider" is set to "ad", this is Not Applicable. Check the path to the X.509 certificate for peer authentication with the following command: # grep -ir tls_cacert /etc/sssd/sssd.conf /etc/sssd/conf.d/*.conf ldap_tls_cacert = /etc/pki/tls/certs/ca-bundle.crt Verify the "ldap_tls_cacert" option points to a file that contains the trusted CA certificate. If this file does not exist, or the option is commented out or missing, this is a finding.

Fix: F-4707r942911_fix

Configure the operating system to implement cryptography to protect the integrity of LDAP remote access sessions. Add or modify the following line in "/etc/sssd/sssd.conf": ldap_tls_cacert = /etc/pki/tls/certs/ca-bundle.crt

b
The Red Hat Enterprise Linux operating system must implement virtual address space randomization.
CM-6 - Medium - CCI-000366 - V-204584 - SV-204584r880794_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-040201
Vuln IDs
  • V-204584
  • V-77825
Rule IDs
  • SV-204584r880794_rule
  • SV-92521
Address space layout randomization (ASLR) makes it more difficult for an attacker to predict the location of attack code he or she has introduced into a process's address space during an attempt at exploitation. Additionally, ASLR also makes it more difficult for an attacker to know the location of existing code in order to repurpose it using return-oriented programming (ROP) techniques.
Checks: C-4708r880792_chk

Verify the operating system implements virtual address space randomization. # grep -r kernel.randomize_va_space /run/sysctl.d/* /etc/sysctl.d/* /usr/local/lib/sysctl.d/* /usr/lib/sysctl.d/* /lib/sysctl.d/* /etc/sysctl.conf 2&gt; /dev/null kernel.randomize_va_space = 2 If "kernel.randomize_va_space" is not configured in the /etc/sysctl.conf file or or in any of the other sysctl.d directories, is commented out or does not have a value of "2", this is a finding. Check that the operating system implements virtual address space randomization with the following command: # /sbin/sysctl -a | grep kernel.randomize_va_space kernel.randomize_va_space = 2 If "kernel.randomize_va_space" does not have a value of "2", this is a finding. If conflicting results are returned, this is a finding.

Fix: F-4708r880793_fix

Configure the operating system implement virtual address space randomization. Set the system to the required kernel parameter by adding the following line to "/etc/sysctl.conf" or a config file in the /etc/sysctl.d/ directory (or modify the line to have the required value): kernel.randomize_va_space = 2 Issue the following command to make the changes take effect: # sysctl --system

b
The Red Hat Enterprise Linux operating system must be configured so that all networked systems have SSH installed.
SC-8 - Medium - CCI-002418 - V-204585 - SV-204585r916422_rule
RMF Control
SC-8
Severity
Medium
CCI
CCI-002418
Version
RHEL-07-040300
Vuln IDs
  • V-204585
  • V-72233
Rule IDs
  • SV-204585r916422_rule
  • SV-86857
Without protection of the transmitted information, confidentiality and integrity may be compromised because unprotected communications can be intercepted and either read or altered. This requirement applies to both internal and external networks and all types of information system components from which information can be transmitted (e.g., servers, mobile devices, notebook computers, printers, copiers, scanners, and facsimile machines). Communication paths outside the physical protection of a controlled boundary are exposed to the possibility of interception and modification. Protecting the confidentiality and integrity of organizational information can be accomplished by physical means (e.g., employing physical distribution systems) or by logical means (e.g., employing cryptographic techniques). If physical means of protection are employed, logical means (cryptography) do not have to be employed, and vice versa. Satisfies: SRG-OS-000423-GPOS-00187, SRG-OS-000424-GPOS-00188, SRG-OS-000425-GPOS-00189, SRG-OS-000426-GPOS-00190
Checks: C-4709r88947_chk

Check to see if sshd is installed with the following command: # yum list installed \*ssh\* libssh2.x86_64 1.4.3-8.el7 @anaconda/7.1 openssh.x86_64 6.6.1p1-11.el7 @anaconda/7.1 openssh-server.x86_64 6.6.1p1-11.el7 @anaconda/7.1 If the "SSH server" package is not installed, this is a finding.

Fix: F-4709r88948_fix

Install SSH packages onto the host with the following commands: # yum install openssh-server.x86_64

b
The Red Hat Enterprise Linux operating system must be configured so that all networked systems use SSH for confidentiality and integrity of transmitted and received information as well as information during preparation for transmission.
SC-8 - Medium - CCI-002418 - V-204586 - SV-204586r916422_rule
RMF Control
SC-8
Severity
Medium
CCI
CCI-002418
Version
RHEL-07-040310
Vuln IDs
  • V-204586
  • V-72235
Rule IDs
  • SV-204586r916422_rule
  • SV-86859
Without protection of the transmitted information, confidentiality and integrity may be compromised because unprotected communications can be intercepted and either 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, then logical means (cryptography) do not have to be employed, and vice versa. Satisfies: SRG-OS-000423-GPOS-00187, SRG-OS-000424-GPOS-00188, SRG-OS-000425-GPOS-00189, SRG-OS-000426-GPOS-00190
Checks: C-4710r88950_chk

Verify SSH is loaded and active with the following command: # systemctl status sshd sshd.service - OpenSSH server daemon Loaded: loaded (/usr/lib/systemd/system/sshd.service; enabled) Active: active (running) since Tue 2015-11-17 15:17:22 EST; 4 weeks 0 days ago Main PID: 1348 (sshd) CGroup: /system.slice/sshd.service 1053 /usr/sbin/sshd -D If "sshd" does not show a status of "active" and "running", this is a finding.

Fix: F-4710r88951_fix

Configure the SSH service to automatically start after reboot with the following command: # systemctl enable sshd.service

b
The Red Hat Enterprise Linux operating system must be configured so that all network connections associated with SSH traffic are terminated after 10 minutes of becoming unresponsive.
SC-10 - Medium - CCI-001133 - V-204587 - SV-204587r917833_rule
RMF Control
SC-10
Severity
Medium
CCI
CCI-001133
Version
RHEL-07-040320
Vuln IDs
  • V-204587
  • V-72237
Rule IDs
  • SV-204587r917833_rule
  • SV-86861
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 the operating system terminates all sessions or network access; it only ends the unresponsive session and releases the resources associated with that session. Satisfies: SRG-OS-000163-GPOS-00072, SRG-OS-000279-GPOS-00109
Checks: C-4711r917831_chk

Verify the SSH server automatically terminates a user session after the SSH client has been unresponsive for 10 minutes. Check for the value of the "ClientAliveInterval" keyword with the following command: # grep -iw clientaliveinterval /etc/ssh/sshd_config ClientAliveInterval 600 If "ClientAliveInterval" is not configured, is commented out, or has a value of "0", this is a finding. If "ClientAliveInterval" has a value that is greater than "600" and is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding.

Fix: F-4711r917832_fix

Note: This setting must be applied in conjunction with RHEL-07-040340 to function correctly. Configure the SSH server to terminate a user session automatically after the SSH client has been unresponsive for 10 minutes. Add the following line (or modify the line to have the required value) to the "/etc/ssh/sshd_config" file (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): ClientAliveInterval 600 The SSH service must be restarted for changes to take effect.

b
The Red Hat Enterprise Linux operating system must be configured so that the SSH daemon does not allow authentication using RSA rhosts authentication.
CM-6 - Medium - CCI-000366 - V-204588 - SV-204588r603261_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-040330
Vuln IDs
  • V-204588
  • V-72239
Rule IDs
  • SV-204588r603261_rule
  • SV-86863
Configuring this setting for the SSH daemon provides additional assurance that remote logon via SSH will require a password, even in the event of misconfiguration elsewhere.
Checks: C-4712r88956_chk

Check the version of the operating system with the following command: # cat /etc/redhat-release If the release is 7.4 or newer this requirement is Not Applicable. Verify the SSH daemon does not allow authentication using RSA rhosts authentication. To determine how the SSH daemon's "RhostsRSAAuthentication" option is set, run the following command: # grep RhostsRSAAuthentication /etc/ssh/sshd_config RhostsRSAAuthentication no If the value is returned as "yes", the returned line is commented out, or no output is returned, this is a finding.

Fix: F-4712r88957_fix

Configure the SSH daemon to not allow authentication using RSA rhosts authentication. Add the following line in "/etc/ssh/sshd_config", or uncomment the line and set the value to "no": RhostsRSAAuthentication no The SSH service must be restarted for changes to take effect.

b
The Red Hat Enterprise Linux operating system must be configured so that all network connections associated with SSH traffic terminate after becoming unresponsive.
SC-10 - Medium - CCI-001133 - V-204589 - SV-204589r917836_rule
RMF Control
SC-10
Severity
Medium
CCI
CCI-001133
Version
RHEL-07-040340
Vuln IDs
  • V-204589
  • V-72241
Rule IDs
  • SV-204589r917836_rule
  • SV-86865
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 the operating system terminates all sessions or network access; it only ends the unresponsive session and releases the resources associated with that session. Satisfies: SRG-OS-000163-GPOS-00072, SRG-OS-000279-GPOS-00109
Checks: C-4713r917834_chk

Verify the SSH server automatically terminates a user session after the SSH client has become unresponsive. Check for the value of the "ClientAliveCountMax" keyword with the following command: # grep -i clientalivecount /etc/ssh/sshd_config ClientAliveCountMax 0 If "ClientAliveCountMax" is not set to "0", this is a finding.

Fix: F-4713r917835_fix

Note: This setting must be applied in conjunction with RHEL-07-040320 to function correctly. Configure the SSH server to terminate a user session automatically after the SSH client has become unresponsive. Add the following line (or modify the line to have the required value) to the "/etc/ssh/sshd_config" file (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): ClientAliveCountMax 0 The SSH service must be restarted for changes to take effect.

b
The Red Hat Enterprise Linux operating system must be configured so that the SSH daemon does not allow authentication using rhosts authentication.
CM-6 - Medium - CCI-000366 - V-204590 - SV-204590r603261_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-040350
Vuln IDs
  • V-204590
  • V-72243
Rule IDs
  • SV-204590r603261_rule
  • SV-86867
Configuring this setting for the SSH daemon provides additional assurance that remote logon via SSH will require a password, even in the event of misconfiguration elsewhere.
Checks: C-4714r88962_chk

Verify the SSH daemon does not allow authentication using known hosts authentication. To determine how the SSH daemon's "IgnoreRhosts" option is set, run the following command: # grep -i IgnoreRhosts /etc/ssh/sshd_config IgnoreRhosts yes If the value is returned as "no", the returned line is commented out, or no output is returned, this is a finding.

Fix: F-4714r88963_fix

Configure the SSH daemon to not allow authentication using known hosts authentication. Add the following line in "/etc/ssh/sshd_config", or uncomment the line and set the value to "yes": IgnoreRhosts yes

b
The Red Hat Enterprise Linux operating system must display the date and time of the last successful account logon upon an SSH logon.
AC-9 - Medium - CCI-000052 - V-204591 - SV-204591r858477_rule
RMF Control
AC-9
Severity
Medium
CCI
CCI-000052
Version
RHEL-07-040360
Vuln IDs
  • V-204591
  • V-72245
Rule IDs
  • SV-204591r858477_rule
  • SV-86869
Providing users with feedback on when account accesses via SSH last occurred facilitates user recognition and reporting of unauthorized account use.
Checks: C-4715r88965_chk

Verify SSH provides users with feedback on when account accesses last occurred. Check that "PrintLastLog" keyword in the sshd daemon configuration file is used and set to "yes" with the following command: # grep -i printlastlog /etc/ssh/sshd_config PrintLastLog yes If the "PrintLastLog" keyword is set to "no", is missing, or is commented out, this is a finding.

Fix: F-4715r88966_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) (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
The Red Hat Enterprise Linux operating system must not permit direct logons to the root account using remote access via SSH.
CM-6 - Medium - CCI-000366 - V-204592 - SV-204592r603261_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-040370
Vuln IDs
  • V-204592
  • V-72247
Rule IDs
  • SV-204592r603261_rule
  • SV-86871
Even though the communications channel may be encrypted, an additional layer of security is gained by extending the policy of not logging on directly as root. In addition, logging on with a user-specific account provides individual accountability of actions performed on the system.
Checks: C-4716r88968_chk

Verify remote access using SSH prevents users from logging on directly as root. Check that SSH prevents users from logging on directly as root with the following command: # grep -i permitrootlogin /etc/ssh/sshd_config PermitRootLogin no If the "PermitRootLogin" keyword is set to "yes", is missing, or is commented out, this is a finding.

Fix: F-4716r88969_fix

Configure SSH to stop users from logging on remotely as the root user. Edit the appropriate "/etc/ssh/sshd_config" file to uncomment or add the line for the "PermitRootLogin" 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): PermitRootLogin no The SSH service must be restarted for changes to take effect.

b
The Red Hat Enterprise Linux operating system must be configured so that the SSH daemon does not allow authentication using known hosts authentication.
CM-6 - Medium - CCI-000366 - V-204593 - SV-204593r603261_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-040380
Vuln IDs
  • V-204593
  • V-72249
Rule IDs
  • SV-204593r603261_rule
  • SV-86873
Configuring this setting for the SSH daemon provides additional assurance that remote logon via SSH will require a password, even in the event of misconfiguration elsewhere.
Checks: C-4717r88971_chk

Verify the SSH daemon does not allow authentication using known hosts authentication. To determine how the SSH daemon's "IgnoreUserKnownHosts" option is set, run the following command: # grep -i IgnoreUserKnownHosts /etc/ssh/sshd_config IgnoreUserKnownHosts yes If the value is returned as "no", the returned line is commented out, or no output is returned, this is a finding.

Fix: F-4717r88972_fix

Configure the SSH daemon to not allow authentication using known hosts authentication. Add the following line in "/etc/ssh/sshd_config", or uncomment the line and set the value to "yes": IgnoreUserKnownHosts yes The SSH service must be restarted for changes to take effect.

c
The Red Hat Enterprise Linux operating system must be configured so that the SSH daemon is configured to only use the SSHv2 protocol.
IA-5 - High - CCI-000197 - V-204594 - SV-204594r877396_rule
RMF Control
IA-5
Severity
High
CCI
CCI-000197
Version
RHEL-07-040390
Vuln IDs
  • V-204594
  • V-72251
Rule IDs
  • SV-204594r877396_rule
  • SV-86875
SSHv1 is an insecure implementation of the SSH protocol and has many well-known vulnerability exploits. Exploits of the SSH daemon could provide immediate root access to the system. Satisfies: SRG-OS-000074-GPOS-00042, SRG-OS-000480-GPOS-00227
Checks: C-4718r88974_chk

Check the version of the operating system with the following command: # cat /etc/redhat-release If the release is 7.4 or newer this requirement is Not Applicable. Verify the SSH daemon is configured to only use the SSHv2 protocol. Check that the SSH daemon is configured to only use the SSHv2 protocol with the following command: # grep -i protocol /etc/ssh/sshd_config Protocol 2 #Protocol 1,2 If any protocol line other than "Protocol 2" is uncommented, this is a finding.

Fix: F-4718r88975_fix

Remove all Protocol lines that reference version "1" in "/etc/ssh/sshd_config" (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). The "Protocol" line must be as follows: Protocol 2 The SSH service must be restarted for changes to take effect.

b
The Red Hat Enterprise Linux operating system must be configured so that the SSH daemon is configured to only use Message Authentication Codes (MACs) employing FIPS 140-2 approved cryptographic hash algorithms.
AC-17 - Medium - CCI-001453 - V-204595 - SV-204595r877394_rule
RMF Control
AC-17
Severity
Medium
CCI
CCI-001453
Version
RHEL-07-040400
Vuln IDs
  • V-204595
  • V-72253
Rule IDs
  • SV-204595r877394_rule
  • SV-86877
DoD information systems are required to use FIPS 140-2 approved cryptographic hash functions. The only SSHv2 hash algorithm meeting this requirement is SHA. The system will attempt to use the first hash presented by the client that matches the server list. Listing the values "strongest to weakest" is a method to ensure the use of the strongest hash available to secure the SSH connection.
Checks: C-4719r622308_chk

Verify the SSH daemon is configured to only use MACs employing FIPS 140-2-approved hashes. Note: If RHEL-07-021350 is a finding, this is automatically a finding as the system cannot implement FIPS 140-2-approved cryptographic algorithms and hashes. Check that the SSH daemon is configured to only use MACs employing FIPS 140-2-approved hashes with the following command: # grep -i macs /etc/ssh/sshd_config MACs hmac-sha2-512,hmac-sha2-256 If any hashes other than "hmac-sha2-512" or "hmac-sha2-256" are listed, the order differs from the example above, they are missing, or the returned line is commented out, this is a finding.

Fix: F-4719r622309_fix

Edit the "/etc/ssh/sshd_config" file to uncomment or add the line for the "MACs" keyword and set its value to "hmac-sha2-512" and/or "hmac-sha2-256" (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): MACs hmac-sha2-512,hmac-sha2-256 The SSH service must be restarted for changes to take effect.

b
The Red Hat Enterprise Linux operating system must be configured so that the SSH public host key files have mode 0644 or less permissive.
CM-6 - Medium - CCI-000366 - V-204596 - SV-204596r603261_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-040410
Vuln IDs
  • V-204596
  • V-72255
Rule IDs
  • SV-204596r603261_rule
  • SV-86879
If a public host key file is modified by an unauthorized user, the SSH service may be compromised.
Checks: C-4720r88980_chk

Verify the SSH public host key files have mode "0644" or less permissive. Note: SSH public key files may be found in other directories on the system depending on the installation. The following command will find all SSH public key files on the system: # find /etc/ssh -name '*.pub' -exec ls -lL {} \; -rw-r--r-- 1 root root 618 Nov 28 06:43 ssh_host_dsa_key.pub -rw-r--r-- 1 root root 347 Nov 28 06:43 ssh_host_key.pub -rw-r--r-- 1 root root 238 Nov 28 06:43 ssh_host_rsa_key.pub If any file has a mode more permissive than "0644", this is a finding.

Fix: F-4720r88981_fix

Note: SSH public key files may be found in other directories on the system depending on the installation. Change the mode of public host key files under "/etc/ssh" to "0644" with the following command: # chmod 0644 /etc/ssh/*.key.pub

b
The Red Hat Enterprise Linux operating system must be configured so that the SSH private host key files have mode 0640 or less permissive.
CM-6 - Medium - CCI-000366 - V-204597 - SV-204597r880743_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-040420
Vuln IDs
  • V-204597
  • V-72257
Rule IDs
  • SV-204597r880743_rule
  • SV-86881
If an unauthorized user obtains the private SSH host key file, the host could be impersonated.
Checks: C-4721r880741_chk

Verify the SSH private host key files have mode "0640" or less permissive. The following command will find all SSH private key files on the system and list their modes: # find / -name '*ssh_host*key' | xargs ls -lL -rw-r----- 1 root ssh_keys 112 Apr 1 11:59 ssh_host_dsa_key -rw-r----- 1 root ssh_keys 202 Apr 1 11:59 ssh_host_key -rw-r----- 1 root ssh_keys 352 Apr 1 11:59 ssh_host_rsa_key If any file has a mode more permissive than "0640", this is a finding.

Fix: F-4721r880742_fix

Configure the mode of SSH private host key files under "/etc/ssh" to "0640" with the following command: # chmod 0640 /path/to/file/ssh_host*key

b
The Red Hat Enterprise Linux operating system must be configured so that the SSH daemon does not permit Generic Security Service Application Program Interface (GSSAPI) authentication unless needed.
CM-3 - Medium - CCI-000318 - V-204598 - SV-204598r853993_rule
RMF Control
CM-3
Severity
Medium
CCI
CCI-000318
Version
RHEL-07-040430
Vuln IDs
  • V-204598
  • V-72259
Rule IDs
  • SV-204598r853993_rule
  • SV-86883
GSSAPI authentication is used to provide additional authentication mechanisms to applications. Allowing GSSAPI authentication through SSH exposes the system's GSSAPI to remote hosts, increasing the attack surface of the system. GSSAPI authentication must be disabled unless needed.
Checks: C-4722r88986_chk

Verify the SSH daemon does not permit GSSAPI authentication unless approved. Check that the SSH daemon does not permit GSSAPI authentication with the following command: # grep -i gssapiauth /etc/ssh/sshd_config GSSAPIAuthentication no If the "GSSAPIAuthentication" keyword is missing, is set to "yes" and is not documented with the Information System Security Officer (ISSO), or the returned line is commented out, this is a finding.

Fix: F-4722r88987_fix

Uncomment the "GSSAPIAuthentication" keyword in "/etc/ssh/sshd_config" (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) and set the value to "no": GSSAPIAuthentication no The SSH service must be restarted for changes to take effect. If GSSAPI authentication is required, it must be documented, to include the location of the configuration file, with the ISSO.

b
The Red Hat Enterprise Linux operating system must be configured so that the SSH daemon does not permit Kerberos authentication unless needed.
CM-3 - Medium - CCI-000318 - V-204599 - SV-204599r853994_rule
RMF Control
CM-3
Severity
Medium
CCI
CCI-000318
Version
RHEL-07-040440
Vuln IDs
  • V-204599
  • V-72261
Rule IDs
  • SV-204599r853994_rule
  • SV-86885
Kerberos authentication for SSH is often implemented using Generic Security Service Application Program Interface (GSSAPI). If Kerberos is enabled through SSH, the SSH daemon provides a means of access to the system's Kerberos implementation. Vulnerabilities in the system's Kerberos implementation may then be subject to exploitation. To reduce the attack surface of the system, the Kerberos authentication mechanism within SSH must be disabled for systems not using this capability.
Checks: C-4723r88989_chk

Verify the SSH daemon does not permit Kerberos to authenticate passwords unless approved. Check that the SSH daemon does not permit Kerberos to authenticate passwords with the following command: # grep -i kerberosauth /etc/ssh/sshd_config KerberosAuthentication no If the "KerberosAuthentication" keyword is missing, or is set to "yes" and is not documented with the Information System Security Officer (ISSO), or the returned line is commented out, this is a finding.

Fix: F-4723r88990_fix

Uncomment the "KerberosAuthentication" keyword in "/etc/ssh/sshd_config" (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) and set the value to "no": KerberosAuthentication no The SSH service must be restarted for changes to take effect. If Kerberos authentication is required, it must be documented, to include the location of the configuration file, with the ISSO.

b
The Red Hat Enterprise Linux operating system must be configured so that the SSH daemon performs strict mode checking of home directory configuration files.
CM-6 - Medium - CCI-000366 - V-204600 - SV-204600r603261_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-040450
Vuln IDs
  • V-204600
  • V-72263
Rule IDs
  • SV-204600r603261_rule
  • SV-86887
If other users have access to modify user-specific SSH configuration files, they may be able to log on to the system as another user.
Checks: C-4724r88992_chk

Verify the SSH daemon performs strict mode checking of home directory configuration files. The location of the "sshd_config" file may vary if a different daemon is in use. Inspect the "sshd_config" file with the following command: # grep -i strictmodes /etc/ssh/sshd_config StrictModes yes If "StrictModes" is set to "no", is missing, or the returned line is commented out, this is a finding.

Fix: F-4724r88993_fix

Uncomment the "StrictModes" keyword in "/etc/ssh/sshd_config" (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) and set the value to "yes": StrictModes yes The SSH service must be restarted for changes to take effect.

b
The Red Hat Enterprise Linux operating system must be configured so that the SSH daemon uses privilege separation.
CM-6 - Medium - CCI-000366 - V-204601 - SV-204601r603261_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-040460
Vuln IDs
  • V-204601
  • V-72265
Rule IDs
  • SV-204601r603261_rule
  • SV-86889
SSH daemon privilege separation causes the SSH process to drop root privileges when not needed, which would decrease the impact of software vulnerabilities in the unprivileged section.
Checks: C-4725r88995_chk

Verify the SSH daemon performs privilege separation. Check that the SSH daemon performs privilege separation with the following command: # grep -i usepriv /etc/ssh/sshd_config UsePrivilegeSeparation sandbox If the "UsePrivilegeSeparation" keyword is set to "no", is missing, or the returned line is commented out, this is a finding.

Fix: F-4725r88996_fix

Uncomment the "UsePrivilegeSeparation" keyword in "/etc/ssh/sshd_config" (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) and set the value to "sandbox" or "yes": UsePrivilegeSeparation sandbox The SSH service must be restarted for changes to take effect.

b
The Red Hat Enterprise Linux operating system must be configured so that the SSH daemon does not allow compression or only allows compression after successful authentication.
CM-6 - Medium - CCI-000366 - V-204602 - SV-204602r880758_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-040470
Vuln IDs
  • V-204602
  • V-72267
Rule IDs
  • SV-204602r880758_rule
  • SV-86891
If compression is allowed in an SSH connection prior to authentication, vulnerabilities in the compression software could result in compromise of the system from an unauthenticated connection, potentially with root privileges.
Checks: C-4726r880756_chk

Note: For RHEL 7.4 and above, this requirement is not applicable. Verify the SSH daemon performs compression after a user successfully authenticates. Check that the SSH daemon performs compression after a user successfully authenticates with the following command: # grep -i compression /etc/ssh/sshd_config Compression delayed If the "Compression" keyword is set to "yes", is missing, or the returned line is commented out, this is a finding.

Fix: F-4726r880757_fix

Uncomment the "Compression" keyword in "/etc/ssh/sshd_config" (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) on the system and set the value to "delayed" or "no": Compression no The SSH service must be restarted for changes to take effect.

b
The Red Hat Enterprise Linux operating system must, for networked systems, synchronize clocks with a server that is synchronized to one of the redundant United States Naval Observatory (USNO) time servers, a time server designated for the appropriate DoD network (NIPRNet/SIPRNet), and/or the Global Positioning System (GPS).
AU-8 - Medium - CCI-001891 - V-204603 - SV-204603r877038_rule
RMF Control
AU-8
Severity
Medium
CCI
CCI-001891
Version
RHEL-07-040500
Vuln IDs
  • V-204603
  • V-72269
Rule IDs
  • SV-204603r877038_rule
  • SV-86893
Inaccurate time stamps make it more difficult to correlate events and can lead to an inaccurate analysis. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. Sources outside the configured acceptable allowance (drift) may be inaccurate. Synchronizing internal information system clocks provides uniformity of time stamps for information systems with multiple system clocks and systems connected over a network. Organizations should consider endpoints that may not have regular access to the authoritative time server (e.g., mobile, teleworking, and tactical endpoints). Satisfies: SRG-OS-000355-GPOS-00143, SRG-OS-000356-GPOS-00144
Checks: C-4727r809209_chk

Check to see if NTP is running in continuous mode: # ps -ef | grep ntp If NTP is not running, check to see if "chronyd" is running in continuous mode: # ps -ef | grep chronyd If NTP or "chronyd" is not running, this is a finding. If the NTP process is found, then check the "ntp.conf" file for the "maxpoll" option setting: # grep maxpoll /etc/ntp.conf server 0.rhel.pool.ntp.org iburst maxpoll 16 If the "maxpoll" option is set to a number greater than 16 or the line is commented out, this is a finding. If the file does not exist, check the "/etc/cron.daily" subdirectory for a crontab file controlling the execution of the "ntpd -q" command. # grep -i "ntpd -q" /etc/cron.daily/* # ls -al /etc/cron.* | grep ntp ntp If a crontab file does not exist in the "/etc/cron.daily" that executes the "ntpd -q" command, this is a finding. If the "chronyd" process is found, then check the "chrony.conf" file for the "maxpoll" option setting: # grep maxpoll /etc/chrony.conf server 0.rhel.pool.ntp.org iburst maxpoll 16 If the option is not set or the line is commented out, this is a finding.

Fix: F-4727r809210_fix

Edit the "/etc/ntp.conf" or "/etc/chrony.conf" file and add or update an entry to define "maxpoll" to "16" as follows: server 0.rhel.pool.ntp.org iburst maxpoll 16 If NTP was running and "maxpoll" was updated, the NTP service must be restarted: # systemctl restart ntpd If NTP was not running, it must be started: # systemctl start ntpd If "chronyd" was running and "maxpoll" was updated, the service must be restarted: # systemctl restart chronyd.service If "chronyd" was not running, it must be started: # systemctl start chronyd.service

b
The Red Hat Enterprise Linux operating system must enable an application firewall, if available.
CM-6 - Medium - CCI-000366 - V-204604 - SV-204604r603261_rule
RMF Control
CM-6
Severity
Medium
CCI
CCI-000366
Version
RHEL-07-040520
Vuln IDs
  • V-204604
  • V-72273
Rule IDs
  • SV-204604r603261_rule
  • SV-86897
Firewalls protect computers from network attacks by blocking or limiting access to open network ports. Application firewalls limit which applications are allowed to communicate over the network. Satisfies: SRG-OS-000480-GPOS-00227, SRG-OS-000480-GPOS-00231, SRG-OS-000480-GPOS-00232
Checks: C-4728r89004_chk

Verify the operating system enabled an application firewall. Check to see if "firewalld" is installed with the following command: # yum list installed firewalld firewalld-0.3.9-11.el7.noarch.rpm If the "firewalld" package is not installed, ask the System Administrator if another firewall application (such as iptables) is installed. If an application firewall is not installed, this is a finding. Check to see if the firewall is loaded and active with the following command: # systemctl status firewalld firewalld.service - firewalld - dynamic firewall daemon Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled) Active: active (running) since Tue 2014-06-17 11:14:49 CEST; 5 days ago If "firewalld" does not show a status of "loaded" and "active", this is a finding. Check the state of the firewall: # firewall-cmd --state running If "firewalld" does not show a state of "running", this is a finding.

Fix: F-4728r89005_fix

Ensure the operating system's application firewall is enabled. Install the "firewalld" package, if it is not on the system, with the following command: # yum install firewalld Start the firewall via "systemctl" with the following command: # systemctl start firewalld

a
The Red Hat Enterprise Linux operating system must display the date and time of the last successful account logon upon logon.
AC-9 - Low - CCI-000052 - V-204605 - SV-204605r858478_rule
RMF Control
AC-9
Severity
Low
CCI
CCI-000052
Version
RHEL-07-040530
Vuln IDs
  • V-204605
  • V-72275
Rule IDs
  • SV-204605r858478_rule
  • SV-86899
Providing users with feedback on when account accesses last occurred facilitates user recognition and reporting of unauthorized account use.
Checks: C-4729r89007_chk

Verify users are provided with feedback on when account accesses last occurred. Check that "pam_lastlog" is used and not silent with the following command: # grep pam_lastlog /etc/pam.d/postlogin session required pam_lastlog.so showfailed If "pam_lastlog" is missing from "/etc/pam.d/postlogin" file, or the silent option is present, this is a finding.

Fix: F-4729r89008_fix

Configure the operating system 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

c
The Red Hat Enterprise Linux operating system must not contain .shosts files.
CM-6 - High - CCI-000366 - V-204606 - SV-204606r603261_rule
RMF Control
CM-6
Severity
High
CCI
CCI-000366
Version
RHEL-07-040540
Vuln IDs
  • V-204606
  • V-72277
Rule IDs
  • SV-204606r603261_rule
  • SV-86901
The .shosts files are used to configure host-based authentication for individual users or the system via SSH. Host-based authentication is n