A custom backup utility has been placed at /usr/local/bin/invbackup with ownership root:backup. The administrator must ensure it always runs with root privileges, can be executed only by the owner and members of the backup group, and is completely inaccessible to all other users. Which single command best accomplishes this goal?
The requirements call for the set-user-ID (setuid) bit so the program always runs with the privileges of the file owner (root). The setuid bit is represented by the leading 4 in a four-digit numeric mode. The owner requires full permissions (rwx, or 7), the group needs read and execute permissions (r-x, or 5), and others need no permissions (0), resulting in the mode 4750.
The command chmod 4750 /usr/local/bin/invbackup is the correct answer.
chmod 4650 /usr/local/bin/invbackup is incorrect because the owner's permissions would be rw- (6), which does not include the execute bit, preventing the owner from running the file.
chmod 2750 /usr/local/bin/invbackup is incorrect because it sets the set-group-ID (setgid) bit (2) instead of the setuid bit, meaning the program would not run with root privileges.
chmod 4755 /usr/local/bin/invbackup is incorrect because it grants read and execute permissions to all other users (5), violating the security requirement that the utility be completely inaccessible to them.
Ask Bash
Bash is our AI bot, trained to help you pass your exam. AI Generated Content may display inaccurate information, always double-check anything important.
What is the purpose of the setuid bit in Linux?
Open an interactive chat with Bash
Why does the ownership root:backup matter in this scenario?
Open an interactive chat with Bash
What does each digit in chmod 4750 signify?
Open an interactive chat with Bash
CompTIA Linux+ XK0-006 (V8)
Security
Your Score:
Report Issue
Bash, the Crucial Exams Chat Bot
AI Bot
Loading...
Loading...
Loading...
IT & Cybersecurity Package Join Premium for Full Access