Linux for Developers Course
Linux for Developers
/
Beginner

Linux Security Best Practices

Definition

The standard set of procedures and configurations used by system administrators to harden a Linux server against attacks.

Explain Like I'm New

Locking the doors, hiding the keys, and changing the default locks before you put a server on the public internet.

Real World Example

A standard server setup checklist: 1) Disable root SSH login. 2) Force SSH Keys instead of passwords. 3) Enable `ufw` firewall. 4) Install `fail2ban`. 5) Apply automated security updates.

Common Use Cases

  • •Hardening production servers
  • •Compliance (SOC2/HIPAA)

Interview Questions

basic

  • Why should you immediately edit `/etc/ssh/sshd_config` to change `PermitRootLogin` to `no`?

intermediate

  • What is 'Principle of Least Privilege' (PoLP)?

Flash Cards

Question

Why disable Root Login?

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Answer

Because every Linux system has a user named `root`. If hackers know the username is `root`, they only have to guess the password. Forcing attackers to guess BOTH the username and the password exponentially increases security.

Question

What is PoLP?

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Answer

A security philosophy. It means a user, program, or service should only be given the bare minimum permissions necessary to perform its job, and absolutely nothing more. (e.g., A web server shouldn't have root access).