TOSS must enforce the limit of five consecutive invalid logon attempts by a user during a 15-minute time period.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-252946 | TOSS-04-020000 | SV-252946r958388_rule | CCI-000044 | medium |
| Description | ||||
| By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. | ||||
| STIG | Date | |||
| Tri-Lab Operating System Stack (TOSS) 4 Security Technical Implementation Guide | 2025-05-08 | |||
Details
Check Text (C-252946r958388_chk)
Verify the "/etc/security/faillock.conf" file is configured to lock an account after three unsuccessful logon attempts within 15 minutes:
$ sudo grep -e "deny =" -e "fail_interval =" /etc/security/faillock.conf
deny = 3
fail_interval = 900
If the "deny" option is set to "0", more than "3", is missing, or is commented out, this is a finding.
If the "fail_interval" option is set to less than "900", is missing, or is commented out, this is a finding.
Note: If the System Administrator demonstrates the use of an approved centralized account management method that locks an account after three unsuccessful logon attempts within a period of 15 minutes, this requirement is Not Applicable.
Fix Text (F-56349r824161_fix)
Configure the operating system to lock an account when three unsuccessful logon attempts occur in 15 minutes.
Add/Modify the "/etc/security/faillock.conf" file to match the following lines:
deny = 3
fail_interval = 900