Vulnerability Discussion

Any password, no matter how complex, can eventually be cracked. Therefore, passwords need to 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

Verify that the Ubuntu operating system enforces a 60-day maximum password lifetime for new user accounts by running the following command:

# grep -i pass_max_days /etc/login.defs
PASS_MAX_DAYS 60

If the "PASS_MAX_DAYS" parameter value is less than 60, or commented out, this is a finding.

Fix

Configure the Ubuntu operating system to enforce a 60-day maximum password lifetime.

Add, or modify the following line in the "/etc/login.defs" file:

PASS_MAX_DAYS 60