| # CIS 5.4.1.1 Ensure password expiration is 90 days or less (Scored) |
| # The PASS_MAX_DAYS parameter in /etc/login.defs allows an administrator to |
| # force passwords to expire once they reach a defined age. It is recommended |
| # that the PASS_MAX_DAYS parameter be set to less than or equal to 90 days. |
| # The window of opportunity for an attacker to leverage compromised credentials |
| # or successfully compromise credentials via an online brute force attack is |
| # limited by the age of the password. Therefore, reducing the maximum age of a |
| # password also reduces an attacker's window of opportunity. |
| # Run the following command and verify PASS_MAX_DAYS is 90 or less: |
| # # grep PASS_MAX_DAYS /etc/login.defs |
| # Verify all users with a password have their maximum days between password |
| # change set to 90 or less: |
| # # egrep ^[^:]+:[^\!*] /etc/shadow | cut -d: -f1 |
| # Maximum number of days between password change: 90 |
| # Set the PASS_MAX_DAYS parameter to 90 in /etc/login.defs : |
| # Modify user parameters for all users with a password set to match: |
| # # chage --maxdays 90 <user> |
| # You can also check this setting in /etc/shadow directly. The 5th field |
| # should be 90 or less for all users with a password. |