XK0-006 Security Practice Question
A system administrator configures PAM to enforce account lockout after 3 failed login attempts. Which PAM module should be used?
⚠ Common exam trap
Candidates often confuse pam_faillock with pam_tally2 (a legacy module) or assume pam_unix alone can enforce lockout, but pam_unix lacks built-in lockout tracking and requires pam_faillock or pam_tally2 for that feature.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
pam_faillock
pam_faillock is the correct PAM module for enforcing account lockout after a specified number of failed login attempts. It tracks failed authentication attempts per user and can lock the account when the threshold (e.g., 3 attempts) is reached, typically by writing to a tally file like /var/log/faillock.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
pam_faillock
Why this is correct
pam_faillock tracks failed authentication attempts per account and locks the account once the configured threshold is reached, satisfying the three-attempt lockout constraint. Unlike pam_tally2, which is deprecated, pam_faillock integrates with the auth and account stacks and supports per-user unlock intervals, making it the current standard module for this enforcement.
- ✗
pam_pwquality
Why it's wrong here
pam_pwquality enforces password strength and complexity rules; it does not count failed authentication attempts or lock accounts. It is tempting because it is a standard PAM module controlling authentication policy, which suits password composition requirements, but lockout after failed logins requires pam_faillock or pam_tally2.
- ✗
pam_securetty
Why it's wrong here
pam_securetty restricts root logins to listed TTYs, so it never counts failed attempts or triggers lockout. It is tempting because it is a security-hardening PAM module, but its purpose is constraining where root may authenticate, not enforcing a failure threshold.
- ✗
pam_unix
Why it's wrong here
pam_unix handles password verification and account expiry, not failed-attempt counting; lockout requires pam_faillock or pam_tally2, which track failures per account. It is tempting because pam_unix is the module that actually authenticates users, so administrators assume it also manages lockout thresholds.
Go deeper
Related to this question
Learn chapter
User and Group Administration
Key term
User
A user is any person, system, or device that interacts with an IT service, resource, or identity system, typically authenticated through credentials and authorized to perform specific actions.
Key term
PAM
Privileged Access Management (PAM) is a security framework that controls, monitors, and audits access to critical systems and accounts with elevated permissions.
About these practice questions
This XK0-006 question is part of Courseiva's 781-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This XK0-006 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the XK0-006 exam.