The answer is that the group permission (r-x) and the umask combine to limit bob to read and execute only, denying write access. This occurs because Linux file permissions for a directory require write permission at the group level to create new files, and the group permission explicitly sets r-x, which excludes the write bit. Even though the umask is set to rwx (000), meaning no bits are masked by the umask itself, the effective permissions are still governed by the most restrictive layer—in this case, the group permission on the directory. On the Systems Security Certified Practitioner SSCP exam, this scenario tests your understanding of how group ownership and umask interact to determine effective permissions, a common trap where candidates mistakenly blame the umask alone. Remember that umask only subtracts from the base permission; it cannot add back a denied bit. A useful memory tip: “Umask subtracts, but group permission gates—if write is missing at the group level, no file creation is possible.”
SSCP Access Controls Practice Question
This SSCP practice question tests your understanding of access controls. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. 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.
Refer to the exhibit. User bob, a member of the projectdev group, attempts to create a new file in /data/project but gets 'Permission denied'. What is the most likely reason?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
The group permission (r-x) and the mask (rwx) combine to limit bob to read and execute only
The effective group permission is determined by the ACL group entry (r-x) and the mask (rwx) – the more restrictive is applied, resulting in r-x, which lacks write.
B
Bob is not the owner of the directory
Why wrong: While owner has rwx, group and other can be restrictive; not being owner does not automatically deny write if group permissions allow it.
C
Bob's effective permissions are limited by the user:alice entry
Why wrong: The user:alice entry applies only to user alice; bob does not have that specific ACL entry.
D
The 'other' permission is '---', blocking all access for users not in the file's user or group
Why wrong: Bob is in the group projectdev, so he is not 'other'; he is covered by the group entry.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The group permission (r-x) and the mask (rwx) combine to limit bob to read and execute only
The directory /data/project has group permissions set to r-x (read and execute) for the projectdev group, and the umask is set to rwx (000), meaning no bits are masked. However, the group permission explicitly denies write access. Since bob is a member of projectdev, his effective permissions are limited to read and execute, preventing file creation.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✓
The group permission (r-x) and the mask (rwx) combine to limit bob to read and execute only
Why this is correct
The effective group permission is determined by the ACL group entry (r-x) and the mask (rwx) – the more restrictive is applied, resulting in r-x, which lacks write.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
Bob is not the owner of the directory
Why it's wrong here
While owner has rwx, group and other can be restrictive; not being owner does not automatically deny write if group permissions allow it.
✗
Bob's effective permissions are limited by the user:alice entry
Why it's wrong here
The user:alice entry applies only to user alice; bob does not have that specific ACL entry.
✗
The 'other' permission is '---', blocking all access for users not in the file's user or group
Why it's wrong here
Bob is in the group projectdev, so he is not 'other'; he is covered by the group entry.
Common exam traps
Common exam trap: answer the scenario, not the keyword
ISC2 often tests the misconception that the 'other' permission applies to group members, when in fact group permissions take precedence for users in the group, and the umask only affects newly created files, not the directory's existing permissions.
Detailed technical explanation
How to think about this question
In Linux, when a user creates a file, the directory must have write permission for the user's effective group or user class. The umask subtracts permissions from the default, but here the umask is rwx (000), so no subtraction occurs; the group permission r-x is the direct restriction. ACLs (Access Control Lists) can override traditional Unix permissions, but the user:alice entry only affects alice, not bob. This scenario is common in shared project directories where group write access is intentionally restricted to prevent accidental modifications.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A security analyst at a medium-sized enterprise encounters this scenario during an investigation or architecture review. The correct answer reflects best practice for the specific threat or control described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Security exam questions test whether you can match controls to threats in context — not just recall definitions.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Access Controls — This question tests Access Controls — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The group permission (r-x) and the mask (rwx) combine to limit bob to read and execute only — The directory /data/project has group permissions set to r-x (read and execute) for the projectdev group, and the umask is set to rwx (000), meaning no bits are masked. However, the group permission explicitly denies write access. Since bob is a member of projectdev, his effective permissions are limited to read and execute, preventing file creation.
What should I do if I get this SSCP question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
This SSCP practice question is part of Courseiva's free ISC2 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 SSCP exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.