Security And File Permissions

You need to prevent a standard user from accidentally deleting a critical configuration file owned by root. Which command ensures the file cannot be modified or deleted even by the root user?

A junior administrator needs to change the permissions of the file /home/bob/notes.txt so that the owner can read and write, the group can read, and others have no access. Which command accomplishes this?

An administrator creates the directory /srv/dropbox and runs 'chmod 1777 /srv/dropbox'. Users report they can create files there, but cannot delete files created by other users. Which TWO statements correctly describe this configuration? (Choose two.)

You have a file 'notes.txt' and you want to ensure the group owner can read and write it, but nobody else can access it. Which chmod command works?

A junior administrator runs `chmod 4755 /usr/local/bin/maintenance.sh` on a shared production server. Later, a standard user executes the script and it performs actions that the user would not normally be permitted to do. Which statement explains this behavior?

Which THREE commands can be used to check user information or current session identity?

A system administrator needs to identify the numerical ID (UID) of the user 'jdoe'. Which file should be checked?

An auditor asks how to confirm which groups the currently logged-in user belongs to, including supplementary groups, from a shell prompt. Which single command displays this information for the invoking user?

A technician must create a new local account named 'intern' on a Linux workstation and wants the command to also create the home directory and skeleton files automatically. Which command accomplishes this with a single invocation on a typical distribution?

A server hosts a directory /srv/dropbox that many users write into. The administrator wants every new file created inside it to automatically belong to the group 'projects' rather than each creator's primary group, without changing anyone's account settings. Which action achieves this?

What is the primary purpose of the /etc/shadow file?

A developer runs `ls -l report.txt` and sees `-rw-r----- 1 alice devs 2048 May 10 09:15 report.txt`. The file must be readable by all members of the `devs` group, but currently only alice can read it. The file's group ownership is already correct. Which command will grant read access to the `devs` group without changing any other permission bits?

A security auditor wants to give a contractor temporary read-only access to a single log file /var/log/app/audit.log without adding the contractor to any group and without granting access to the rest of the directory. Which approach best matches least-privilege practice?

Which command removes a group named 'tempgroup' from the system?

You notice a file has permissions listed as '-rwsr-xr-x'. What does the 's' in the owner's position indicate?

You are the administrator of a shared Linux workstation. A new employee needs to be added to the existing group 'research' so they can access group-owned project files. Which command accomplishes this?

You are configuring a temporary directory where multiple users save files. To ensure that users can only delete their own files and not files created by others, what must you set?

An administrator creates a directory `/srv/dropbox` with mode 1777 so that several contractors can deposit files. Later, one contractor reports that a file they uploaded vanished, and `ls -l /srv/dropbox` shows the directory still has its sticky bit set. Which statement best explains the situation?

Which TWO of the following locations or methods are commonly used to define where a user's home directory is located?

A junior administrator runs `chmod g+s /srv/reports` on a directory that is owned by root:finance and then creates a file inside it as the user `alice`, who is a member of the finance group. Which ownership will the newly created file have?

A user named bob has a primary group of users and is also a member of the group auditors. He creates a new file called notes.txt in his home directory. The system's default umask is 022. Which command would change the group ownership of notes.txt to auditors without altering its permissions?

A user runs `umask` and sees `0022`. They create a new regular file with `touch report.txt`. Which permissions will the new file most likely have, and why?

To add a new user named 'guest' and set their home directory to '/home/guest', which command is correct?

A file named payroll.csv has permissions -rw-r-----. The user owner is carol, and the group owner is hr. A user named dave, who is not carol and not a member of hr, attempts to read the file. What will happen?

A user reports that a script at /usr/local/bin/backup.sh runs with the permissions of the file's owner rather than the user who invoked it, and that this behaviour is intentional for a scheduled task. Which permission bit is responsible for this behaviour?

Which TWO of these tools can modify file ownership or permissions?

You want to change the owner of 'data.txt' from 'user1' to 'user2' AND the group from 'group1' to 'group2' in one command. Which is correct?

A junior administrator is troubleshooting a payroll application and runs 'ls -l /srv/payroll/run.sh'. The output shows '-rwxr-x--- 1 root finance 2048 Apr 10 09:14 /srv/payroll/run.sh'. A member of the 'marketing' group complains the script fails with 'Permission denied'. What is the most likely reason?

A developer wants a shell script named `deploy.sh` located in the current directory to be runnable by typing `./deploy.sh`, but currently the command returns 'Permission denied' even though the file contains valid commands. Which command resolves the problem?

You want to change the primary group of an existing user named 'bob' to 'staff'. Which command should you use?

Which directory contains the user accounts' password hashes and aging data on most modern Linux systems?

A contractor needs to run a diagnostic script that requires reading a log file owned by `root` with mode `640` and group `adm`. The contractor's account `contractor` has primary group `contractor` but has been added as a supplementary member of `adm`. Which statement describes what will happen when the contractor attempts to read the file?

A user wants to view the permissions of all files in a directory, including hidden files, in a long listing format. Which command should they use?

A junior administrator needs to change the ownership of the file `/var/www/html/index.html` from user `deploy` to user `www-data`, while leaving the group ownership and all permission bits exactly as they are. Which command should be used?

You are managing a directory shared by a project team. You want all files created in this directory to automatically belong to the 'developers' group, regardless of the user's primary group. Which command achieves this?

A developer runs `mkdir /srv/collab` on an ext4 filesystem, then runs `chmod 2775 /srv/collab` so that the directory is owned by root:devteam. Later, a member of the devteam group creates a file inside /srv/collab with their default umask of 022. Which group will own the newly created file?

Which THREE commands are related to viewing or changing group memberships?

You want to set a default umask of 027 for all users. Which file should you edit to apply this globally?

You need to create a new group named 'audit'. Which command should you execute?

Which permission bit must be set on a directory to allow a user to enter the directory and access files within it?

Which TWO of the following are true about the 'others' category of file permissions?

Which THREE of the following are special permission bits in Linux?

A security audit requires reviewing which local accounts exist on a Linux server, which of them have usable login shells, and which groups each account belongs to. Which TWO commands or files provide authoritative local account and group membership information? (Choose two.)

A user complains they cannot read a file. The file has permissions 640 and is owned by root, but the user is in the group that owns the file. Why can't they read it?

Which THREE of these are valid types of permissions in Linux file systems?

What is the result of running 'chmod 000 secret.txt'?

A junior administrator needs to let a colleague in the accounting group read and write the shared report at /srv/reports/q3.csv, but no one outside that group should have any access. The file is currently owned by the administrator. Which command accomplishes this by changing only the group ownership to 'accounting'?

Which TWO statements regarding the 'umask' command are correct?

Which command-line tool is used to display the groups a specific user belongs to?

You want to delete a user account named 'baduser' and also remove their home directory. Which command is correct?

A system administrator creates a shared directory /srv/collab and sets its permissions to 1777. Users report that they can create files but cannot delete files created by other users. Which statement describes the effect of the leading 1 in the permission mode?

Which file permission represents read, write, and execute for the owner, and read-only for group and others?

A user's account has been compromised. Which command is the most effective way to lock the user account immediately while preserving their files?

A shared project directory `/srv/team` is owned by user `lead` and group `team`. Team members must be able to create, edit, and delete each other's files, and every new file must automatically belong to the `team` group even when created by a user whose primary group is something else. The directory already has permissions `drwxrwx---`. Which single action accomplishes the group inheritance requirement?

A file is owned by root and has permissions 600. What happens if a regular user tries to read this file?

An administrator wants to allow a user named carol to read a file /etc/secure.conf that is owned by root:root with permissions 600, without changing the file's permissions or adding carol to the root group. Which command should the administrator use?

Which THREE commands are used to manage user account lifecycle?

You are hardening a server and must ensure that ordinary users cannot read the contents of `/etc/shadow`. Which two statements about `/etc/shadow` access are correct? (Choose two.)

A developer stores a private SSH key at /home/dev/id_rsa and wants to remove all permissions for group and others while keeping full owner access, using octal notation. Which command achieves exactly this?

A user named alice has a primary group alice and is also a member of the group developers. She creates a new file named report.txt in her home directory. The umask is set to 022. What are the permissions of the newly created file?