Vulnerability Discussion
Any password, no matter how complex, can eventually be cracked. Therefore, Passwords must 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.
Check
Check whether the maximum time period for existing passwords is restricted to 60 days with the following command:
$ awk -F: '$5 <= 0 || $5 > 60 {print $1 " " $5}' /etc/shadow
If any results are returned that are not associated with a system account, this is a finding.
Fix
Configure noncompliant accounts to enforce a 60-day maximum password lifetime restriction using the following command, substituting in the username:
$ chage -M 60 [user]