GIAC Foundational Cybersecurity Technologies Practice Test

Which of the following Linux permissions would allow the owner of a file to read, write, and execute a file while allowing everyone else to read and execute?

1. 755

2. 700

3. 644

4. 411

The correct answer is: 755

The answer 755 correctly represents the permissions set that would allow the owner of a file to read, write, and execute the file, while allowing everyone else to read and execute it. In Linux, permissions are represented in a three-digit octal format, where each digit corresponds to the user, group, and others respectively. In this case: - The first digit, 7, signifies the permissions for the owner of the file. The number 7 is the sum of read (4), write (2), and execute (1) permissions, allowing the owner full control over the file. - The second digit, 5, represents the permissions for the group. The number 5 is the sum of read (4) and execute (1) permissions, thereby permitting group members to read and execute the file, but not to write to it. - The third digit, again 5, applies to others (everyone else), allowing them to read and execute the file without write access. Collectively, the permission set 755 provides the necessary access specified in the question: the owner has complete control, while all other users can only read and execute. In contrast, the other choices do not meet the requirements specified: - 700 limits permissions