XK0-006 Security Practice Question
A security audit reveals that the /etc/shadow file is readable by all users. What is the most appropriate immediate action?
⚠ Common exam trap
The XK0-005 exam often tests the misconception that simply setting restrictive permissions (like 600) is sufficient, without also ensuring the correct group ownership (shadow), which is a common oversight in Linux security hardening.
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
✓
chmod 600 /etc/shadow && chown root:shadow /etc/shadow
The /etc/shadow file stores hashed user passwords and must be protected from unauthorized access. The correct command is `chmod 600 /etc/shadow && chown root:shadow /etc/shadow` because it sets the file to be readable and writable only by the owner (root) and changes the group to 'shadow', which is the standard group used by many Linux distributions to allow certain system utilities (like `pwck` or `unix_chkpwd`) to read the file without granting access to all users. This ensures that only root and members of the shadow group can read the file, immediately fixing the security issue.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
chmod 000 /etc/shadow
Why it's wrong here
Removes all permissions, including root's, preventing login.
- ✓
chmod 600 /etc/shadow && chown root:shadow /etc/shadow
Why this is correct
Sets proper permissions and ownership to root and shadow group.
- ✗
chmod 640 /etc/shadow
Why it's wrong here
Allows group read access; should be restricted to root.
- ✗
chmod 600 /etc/shadow
Why it's wrong here
Only root can read/write; correct, but not most appropriate yet.
Go deeper
Related to this question
Learn chapter
Linux Fundamentals and History
Key term
chown
chown is a Linux/Unix command used to change the owner and group associated with a file or directory.
Key term
chmod
chmod is a command in Linux and Unix-like operating systems used to change the permissions (read, write, execute) of a file or directory.
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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.