CompTIA Security Plus Mock Test Q1001

A file on a Linux server has default permissions of rw-rw-r–. The system administrator has verified that Ann, a user, is not a member of the group owner of the file. Which of the following should be modified to assure that Ann has read access to the file?

A. User ownership information for the file in question
B. Directory permissions on the parent directory of the file in question
C. Group memberships for the group owner of the file in question
D. The file system access control list (FACL) for the file in question

Correct Answer: C
Section: Access Control and Identity Management

Explanation:
The file permissions according to the file system access control list (FACL) are rw-rw-r–.
The first ‘rw-‘ are the file owner permissions (read and write).
The second ‘rw-‘ are the group permissions (read and write) for the group that has been assigned the file.
The third ‘r–‘ is the All Users permissions; in this case read only.
To enable Ann to access the file, we should add Ann to the group that has been assigned to the file.

Incorrect Answers:
A: You should not modify the ownership of the file to give another user access to the file. Therefore, this answer is incorrect.
B: Ann only needs to access the file, not the entire directory so you should not modify the permissions of the directory. Therefore, this answer is incorrect.
C: You should not modify Group memberships for the group owner of the file to give another user access to the file. Therefore, this answer is incorrect.

References:
https://www.linux.com/learn/tutorials/309527-understanding-linux-file-permissions
Topic 6, Cryptography