| name | cis-ubuntu1804-v220-4-4-2 |
| description | Ensure lockout for failed password attempts is configured |
| category | cis-iam |
| version | 2.2.0 |
| author | cyberstrike-official |
| tags | ["cis","ubuntu","linux","ubuntu-18.04","pam","authentication"] |
| cis_id | 4.4.2 |
| cis_benchmark | CIS Ubuntu Linux 18.04 LTS Benchmark v2.2.0 |
| tech_stack | ["ubuntu","linux"] |
| cwe_ids | [] |
| chains_with | [] |
| prerequisites | [] |
| severity_boost | {} |
CIS Ubuntu Linux 18.04 LTS Benchmark v2.2.0 - Control 4.4.2
Profile Applicability
- Level 1 - Server
- Level 1 - Workstation
Description
Lock out users after n unsuccessful consecutive login attempts. The first set of changes are made to the PAM configuration files. The second set of changes are applied to the program specific PAM configuration file. Set the lockout number to the site's policy.
deny = 4 - deny access if tally for this user exceeds 4unlock_time = 900 - allow access after 900 seconds (15 minutes) after failed attempt. If this option is used together with deny, unlock_time is the time after a failed attempt before access can be attempted again.
Rationale
Locking out user IDs after n unsuccessful consecutive login attempts mitigates brute force password attacks against your systems.
Audit Procedure
Command Line
Verify the pam_tally2 or pam_faillock module is configured:
grep -Pi '^\h*auth\h+(required|requisite)\h+pam_(tally2|faillock)\.so' /etc/pam.d/common-auth
Expected Result
auth required pam_tally2.so onerr=fail audit silent deny=5 unlock_time=900
OR pam_faillock equivalent.
Remediation
Command Line
Edit /etc/pam.d/common-auth and add or modify the following line:
auth required pam_tally2.so onerr=fail audit silent deny=5 unlock_time=900
Edit /etc/pam.d/common-account and add or modify the following line:
account requisite pam_deny.so
account required pam_tally2.so
References
- NIST SP 800-53 Rev. 5: AC-7
CIS Controls
v8 - 6.2 Establish an Access Revoking Process - Establish and follow a process, ideally automated, for revoking access to enterprise assets.
v7 - 16.7 Establish Process for Revoking Access.
Profile Applicability
- Level 1 - Server
- Level 1 - Workstation
Assessment Status
Automated
