Linux Server Security Checklist: 20 Essential Hardening Steps

Why Server Hardening Is Critical

A fresh Linux VPS has a default configuration optimized for ease of use, not security. Attackers scan for vulnerable servers 24/7. Follow this checklist within the first hour of setting up any new server.

The Checklist

1. Disable root SSH login — Create a sudo user and set PermitRootLogin no in /etc/ssh/sshd_config

2. Use SSH keys only — Disable password authentication entirely

3. Change the SSH port — Move from 22 to a non-standard port to reduce automated attacks

4. Install fail2ban — Automatically bans IPs after failed login attempts

5. Enable unattended upgrades — Auto-install security patches without manual intervention

6. Configure UFW firewall — Allow only the ports you actually need

7. Install rkhunter — Scans for rootkits and suspicious files

8. Set up logwatch — Daily email summaries of server activity