Ubuntu 24.04 LTS must automatically lock an account until the locked account is released by an administrator when three unsuccessful logon attempts have been made.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-270690 | UBTU-24-200610 | SV-270690r1067126_rule | CCI-000044 | low |
| Description | ||||
| By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-forcing, is reduced. Limits are imposed by locking the account. Satisfies: SRG-OS-000021-GPOS-00005, SRG-OS-000329-GPOS-00128 | ||||
| STIG | Date | |||
| Canonical Ubuntu 24.04 LTS Security Technical Implementation Guide | 2025-05-16 | |||
Details
Check Text (C-270690r1067126_chk)
Verify that Ubuntu 24.04 LTS utilizes the "pam_faillock" module with the following command:
$ grep faillock /etc/pam.d/common-auth
auth [default=die] pam_faillock.so authfail
auth sufficient pam_faillock.so authsucc
If the pam_faillock.so module is not present in the "/etc/pam.d/common-auth" file, this is a finding.
Verify the pam_faillock module is configured to use the following options:
$ sudo egrep 'silent|audit|deny|fail_interval| unlock_time' /etc/security/faillock.conf
audit
silent
deny = 3
fail_interval = 900
unlock_time = 0
If the "silent" keyword is missing or commented out, this is a finding.
If the "audit" keyword is missing or commented out, this is a finding.
If the "deny" keyword is missing, commented out, or set to a value greater than "3", this is a finding.
If the "fail_interval" keyword is missing, commented out, or set to a value greater than "900", this is a finding.
If the "unlock_time" keyword is missing, commented out, or not set to "0", this is a finding.
Fix Text (F-74624r1066558_fix)
Configure Ubuntu 24.04 LTS to utilize the "pam_faillock" module.
Edit the /etc/pam.d/common-auth file to add the following lines below the "auth" definition for pam_unix.so:
auth [default=die] pam_faillock.so authfail
auth sufficient pam_faillock.so authsucc
Configure the "pam_faillock" module to use the following options:
Edit the /etc/security/faillock.conf file and add/update the following keywords and values:
audit
silent
deny = 3
fail_interval = 900
unlock_time = 0