Vulnerability Discussion

Inactive identifiers pose a risk to systems and applications because attackers may exploit an inactive identifier and potentially obtain undetected access to the system.

Disabling inactive accounts ensures that accounts which may not have been responsibly removed are not available to attackers who may have compromised their credentials.

Owners of inactive accounts will not notice if unauthorized access to their user account has been obtained.

Check

Verify that RHEL 9 account identifiers (individuals, groups, roles, and devices) are disabled after 35 days of inactivity with the following command:

Check the account inactivity value by performing the following command:

$ sudo grep -i inactive /etc/default/useradd

INACTIVE=35

If "INACTIVE" is set to "-1", a value greater than "35", or is commented out, this is a finding.

Fix

Configure RHEL 9 to disable account identifiers after 35 days of inactivity after the password expiration.

Run the following command to change the configuration for useradd:

$ sudo useradd -D -f 35

The recommendation is 35 days, but a lower value is acceptable.