Lynis is a battle-tested security auditing tool for Linux systems. It performs in-depth inspections of your server configuration and provides prioritised hardening recommendations. This guide installs and runs Lynis on Ubuntu 24.04 LTS.

Tested and valid on:

  • Ubuntu 24.04 LTS

Prerequisites

  • Ubuntu 24.04 LTS server
  • A user with sudo privileges

Step 1 – Install Lynis

Install from the Ubuntu repositories:

sudo apt update
sudo apt install lynis -y

Step 2 – Update Lynis

Ensure you have the latest version:

sudo lynis update info

Step 3 – Run a Full System Audit

Perform a complete audit of the system:

sudo lynis audit system

The audit takes 2–5 minutes and produces a detailed report.

Step 4 – Review the Hardening Index

Lynis reports a Hardening Index (0–100) at the end of the scan. A score of 70+ is considered acceptable for production systems.

Step 5 – View Warnings and Suggestions

Filter the report for actionable items:

sudo grep -E 'WARNING|SUGGESTION' /var/log/lynis.log | head -40

Step 6 – View the Full Report

Read the complete audit log:

sudo cat /var/log/lynis-report.dat | head -100

Step 7 – Schedule Regular Audits

Run weekly audits with cron:

echo '0 2 * * 0 root /usr/bin/lynis audit system --quiet --logfile /var/log/lynis-weekly.log' | sudo tee /etc/cron.d/lynis

Conclusion

Lynis has audited your Ubuntu 24.04 LTS server. Address the highest-priority warnings first and re-run the audit after each fix to track your improvement over time.