Vulnerability Discussion
Enabling PAM password complexity permits enforcement of strong passwords and consequently makes the system less prone to dictionary attacks.
Check
Verify RHEL 9 uses "pwquality" to enforce the password complexity rules in the system-auth file with the following command:
$ cat /etc/pam.d/system-auth | grep pam_pwquality
password required pam_pwquality.so
If the command does not return a line containing the value "pam_pwquality.so", or the line is commented out, this is a finding.
If the system administrator (SA) can demonstrate that the required configuration is contained in a PAM configuration file included or substacked from the system-auth file, this is not a finding.
Fix
Configure RHEL 9 to use "pwquality" to enforce password complexity rules.
Add the following line to the "/etc/pam.d/system-auth" file(or modify the line to have the required value):
password required pam_pwquality.so