RHEL 9 must automatically lock the root account until the root account is released by an administrator when three unsuccessful logon attempts occur during a 15-minute time period.

STIG ID: RHEL-09-411080  |  SRG: SRG-OS-000329-GPOS-00128 |  Severity: medium |  CCI: CCI-000044,CCI-002238 |  Vulnerability Id: V-258055

Vulnerability Discussion

By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, also known as brute-forcing, is reduced. Limits are imposed by locking the account.

Satisfies: SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005

Check

Verify RHEL 9 is configured to lock the root account after three unsuccessful logon attempts with the command:

$ sudo grep even_deny_root /etc/security/faillock.conf

even_deny_root

If the "even_deny_root" option is not set or is missing or commented out, this is a finding.

Fix

To configure RHEL 9 to lock out the "root" account after a number of incorrect logon attempts using "pam_faillock.so", first enable the feature using the following command:

$ sudo authselect enable-feature with-faillock

Edit the "/etc/security/faillock.conf" by uncommenting or adding the following line:

even_deny_root