Linux security fundamentals in Cybersecurity - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the primary purpose of the Linux file permissions system?

The Linux file permissions system controls who can read, write, or execute files and directories, helping to protect data from unauthorized access.

beginner

What does the 'root' user represent in Linux?

The 'root' user is the superuser in Linux with full control over the system, able to perform any action without restrictions.

beginner

Why is it important to keep Linux software updated?

Updating Linux software fixes security vulnerabilities and bugs, reducing the risk of attacks and keeping the system safe.

beginner

What is the role of a firewall in Linux security?

A firewall controls incoming and outgoing network traffic based on security rules, helping to block unauthorized access to the Linux system.

intermediate

What is SELinux and why is it used?

SELinux (Security-Enhanced Linux) adds an extra layer of security by enforcing strict access controls on processes and files beyond standard permissions.

Which Linux user has unrestricted access to all commands and files?

A root

B guest

C admin

D user

The root user is the superuser with full system access.

What does the 'chmod' command do in Linux?

A Changes file ownership

B Changes file name

C Changes file permissions

D Changes file location

chmod modifies the read, write, and execute permissions of files or directories.

Why should you avoid running everyday tasks as the root user?

A It can accidentally cause system damage

B It slows down the system

C It uses more memory

D It disables security updates

Using root for daily tasks risks accidental changes that can harm the system.

Which tool is commonly used to manage firewall rules on Linux?

A grep

B cron

C ssh

D iptables

iptables is a standard tool to configure Linux firewall rules.

What is the main benefit of using SELinux?

A Improves system speed

B Provides enhanced access control

C Simplifies user management

D Automatically updates software

SELinux enforces strict access controls beyond normal permissions.

Explain how Linux file permissions help secure a system.

Think about who can do what with files and folders.

Describe the role of the root user and why it should be used carefully.

Consider why having all power can be dangerous.