To check how many lowercase characters are required in a password, run the following command:
$ grep pam_cracklib /etc/pam.d/system-auth
The "lcredit" parameter (as a negative number) will indicate how many special characters are required. The DoD requires at least one lowercase character in a password. This would appear as "lcredit=-1". If lcredit is not found or not set to the required value, this is a finding.
Fix Text (F-43519r1_fix)
The pam_cracklib module's "lcredit=" parameter controls requirements for usage of lowercase letters in a password. When set to a negative number, any password will be required to contain that many lowercase characters. When set to a positive number, pam_cracklib will grant +1 additional length credit for each lowercase character. Add "lcredit=-1" after pam_cracklib.so to require use of a lowercase character in passwords.