Title

RHEL 8 must be configured in the password-auth file to prohibit password reuse for a minimum of five generations. (Cat II impact)

Discussion

Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. If the information system or application allows the user to reuse their password consecutively when that password has exceeded its defined lifetime, the end result is a password that is not changed per policy requirements. RHEL 8 uses "pwhistory" consecutively as a mechanism to prohibit password reuse. This is set in both: /etc/pam.d/password-auth /etc/pam.d/system-auth. Note that manual changes to the listed files may be overwritten by the "authselect" program.

Check Content

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

Fix Text

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

Additional Identifiers

Rule ID: SV-230368r902759_rule

Vulnerability ID: V-230368

Group Title: SRG-OS-000077-GPOS-00045

Expert Comments

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