- A
Change SSH port to 2222
Why wrong: Security through obscurity, not a strong measure.
- B
Configure pam_faillock.so to lock accounts after failed attempts
Prevents brute force.
- C
Configure pam_pwquality.so to enforce password complexity
Enforces strong passwords.
- D
Set PasswordAuthentication no in sshd_config
Forces key-based authentication.
- E
Set PermitRootLogin yes
Why wrong: Reduces security.
Question 72 of 1,000
XK0-005 Security Practice Question
This XK0-005 practice question tests your understanding of security. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A security audit reveals that a Linux system allows password-based SSH logins and has weak password policies. Which THREE actions should the administrator take to improve security? (Choose three.)
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
✓
Configure pam_faillock.so to lock accounts after failed attempts
Disabling password authentication, enforcing password complexity via pam_pwquality, and setting account lockout via pam_faillock are three strong measures. Changing SSH port is a minor hardening but not as effective as the other three. Enabling root login is bad.
Key principle: ACLs process entries top to bottom and stop at the first match. Entry order and interface direction matter as much as the permit or deny statement.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Change SSH port to 2222
Why it's wrong here
Security through obscurity, not a strong measure.
- ✓
Configure pam_faillock.so to lock accounts after failed attempts
Why this is correct
Prevents brute force.
Related concept
Standard ACLs match source addresses.
- ✓
Configure pam_pwquality.so to enforce password complexity
Why this is correct
Enforces strong passwords.
Related concept
Standard ACLs match source addresses.
- ✓
Set PasswordAuthentication no in sshd_config
Why this is correct
Forces key-based authentication.
Related concept
Standard ACLs match source addresses.
- ✗
Set PermitRootLogin yes
Why it's wrong here
Reduces security.
Common exam traps
Common exam trap: ACLs stop at the first match
ACLs are processed top to bottom. The first matching entry wins, and an implicit deny usually exists at the end.
Detailed technical explanation
How to think about this question
ACL questions test precision: source, destination, protocol, port and direction. A generally correct ACL can still fail if it is applied on the wrong interface or in the wrong direction.
KKey Concepts to Remember
- Standard ACLs match source addresses.
- Extended ACLs can match source, destination, protocol and ports.
- The first matching ACL entry is used.
- There is usually an implicit deny at the end.
TExam Day Tips
- Check inbound versus outbound direction.
- Read the ACL from top to bottom.
- Look for a broader permit or deny above the intended line.
Key takeaway
ACLs process entries top to bottom and stop at the first match. Entry order and interface direction matter as much as the permit or deny statement.
Real-world example
How this comes up in practice
A security administrator must allow nursing staff to reach a patient records server while blocking access from the guest Wi-Fi VLAN. After applying an extended ACL, traffic is still blocked from nursing workstations. The ACL was applied outbound instead of inbound on the wrong interface. Questions like this test ACL direction and placement rules.
What to study next
Got this wrong? Here's your next step.
Review ACL processing order, placement rules (standard near destination, extended near source), and inbound vs outbound direction. Study wildcard masks and implicit deny. Then practise related XK0-005 ACL questions on filtering logic and placement.
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FAQ
Questions learners often ask
What does this XK0-005 question test?
Security — This question tests Security — Standard ACLs match source addresses..
What is the correct answer to this question?
The correct answer is: Configure pam_faillock.so to lock accounts after failed attempts — Disabling password authentication, enforcing password complexity via pam_pwquality, and setting account lockout via pam_faillock are three strong measures. Changing SSH port is a minor hardening but not as effective as the other three. Enabling root login is bad.
What should I do if I get this XK0-005 question wrong?
Review ACL processing order, placement rules (standard near destination, extended near source), and inbound vs outbound direction. Study wildcard masks and implicit deny. Then practise related XK0-005 ACL questions on filtering logic and placement.
What is the key concept behind this question?
Standard ACLs match source addresses.
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Last reviewed: Jul 4, 2026
This XK0-005 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 XK0-005 exam.
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