Vulnerability Discussion
Enabling PAM password complexity permits enforcement of strong passwords and consequently makes the system less prone to dictionary attacks.
Check
Verify AlmaLinux OS 9 uses "pwquality" to enforce the password complexity rules in the password-auth file with the following command:
Check for the use of the "pwquality" module in the PAM auth files with the following command:
$ grep pam_pwquality.so /etc/pam.d/system-auth /etc/pam.d/password-auth
/etc/pam.d/system-auth:password required pam_pwquality.so retry=3
/etc/pam.d/password-auth:password required pam_pwquality.so retry=3
If the command does not return a line in each file 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 AlmaLinux OS 9 to use "pwquality" to enforce password complexity rules.
Add the following line to the "/etc/pam.d/system-auth" and "/etc/pam.d/password-auth" files (or modify the line to have the required value):
password required pam_pwquality.so retry=3