The Ubuntu Security Guide
Security Technical Implementation Guides like the CIS benchmark or DISA-STIG have hundreds of configuration recommendations, so hardening and auditing a Linux system manually can be very tedious. Ubuntu Security Guide (USG) is a new tool available with Ubuntu 20.04 LTS that greatly improves the usability of hardening and auditing, and allows for environment-specific customizations. The following sections provide more information on hardening and auditing with usg.
For a quick start with Ubuntu Security Guide for CIS or DISA-STIG consider using this tutorial.