CIS Ubuntu Linux 18.04 LTS Benchmark v2.2.0 - Control 4.5.1.3
Profile Applicability
- Level 1 - Server
- Level 1 - Workstation
Description
The PASS_WARN_AGE parameter in /etc/login.defs allows an administrator to notify users that their password will expire in a defined number of days. It is recommended that the PASS_WARN_AGE parameter be set to 7 or more days.
Rationale
Providing an advance warning that a password will be expiring gives users time to think of a secure password. Users caught unaware may choose a simple password or write it down where it may be discovered.
Audit Procedure
Command Line
Run the following command and verify PASS_WARN_AGE is 7 or more:
grep -Pi '^\h*PASS_WARN_AGE\h+\d+\b' /etc/login.defs
Verify all users with a password have their warning days set:
awk -F: '($2~/^\$.+\$/){print $1 " " $6}' /etc/shadow
Expected Result
PASS_WARN_AGE should be 7 or more in /etc/login.defs.
No user should have a value less than 7 in field 6 of /etc/shadow.
Remediation
Command Line
Set the PASS_WARN_AGE parameter to 7 in /etc/login.defs:
PASS_WARN_AGE 7
Modify user parameters for all users with a password set to match:
chage --warndays 7 <user>
Default Value
PASS_WARN_AGE 7
References
- NIST SP 800-53 Rev. 5: IA-5, CM-6
CIS Controls
v8 - 5.2 Use Unique Passwords - Use unique passwords for all enterprise assets.
v7 - 4.4 Use Unique Passwords.
Profile Applicability
- Level 1 - Server
- Level 1 - Workstation
Assessment Status
Automated
