Security audits with Lynis
Professional Hardening
The complexity of modern distributions offers many potential attack vectors for malware. Lynis lets you find these vulnerabilities before an attacker does.
Virtually nobody uses a computer without Internet access. Unfortunately, the network of networks is teeming with malicious programs that exploit vulnerabilities in operating systems, firmware, and application programs looking to inject malware or steal personal data.
Sys admins protect their systems against these attacks as part of their daily grind. Home users also need to protect their systems by keeping their computers up to date and running an occasional security scan to detect any vulnerabilities. Lynis [1], a free software tool from CISOfy, covers a wide range of problem scenarios and lets you perform regular system checks in no time at all.
First Launch
Lynis, a command-line program, comes with a collection of scripts for Unix-style systems. These scripts check various vulnerable system components for insecure settings and display color-coded results.
You will find Lynis in the repositories of many distributions and can install it using any of the popular package management tools. You also can download Lynis from the CISOfy website. I recommend this approach because you will always find the latest version there [2]. CISOfy (located in Vlijmen, Netherlands) offers the community variant of Lynis free of charge. The download contains the actual application, but some additional programs and the Collector are missing. Lynis comes with some community plugins out of the box.
Lynis Enterprise
For companies that need to monitor more than 10 workstations, CISOfy offers Lynis Enterprise, which is available as a software as a service (SaaS, a licensing and sales model where the provider operates software on their own infrastructure and offers a subscription model for use). Lynis Enterprise comes with numerous plugins and additionally generates web-based reports in line with various standards. The Enterprise variant also lets you check Docker files in container environments and monitor remote computer systems.
CISOfy offers the SaaS version of Lynis Enterprise as a subscription for $3 per month. For larger organizations that require monitoring of more than 100 workstations, a self-hosted package is available for setting up a local Lynis instance on the intranet. The self-hosted Enterprise variant also includes all of the additional packages and is suitable for services that provide security audits for other companies [3].
At Your Command
You will find detailed instructions for installing the Lynis community variant on various distributions [4] on the CISOfy website. You then execute the program by typing lynis <parameter>
in a terminal window. To access the available command parameters, type lynis show
.
The central command for auditing the local system is lynis audit system
. The application now runs over 200 test parameters and displays the results in a simple table after a short wait (Figure 1). To the right of each test category, the results appear in green, yellow, or red. If the results are displayed in yellow, you need to check the setting, but if the text color is red, you will want to reconfigure the service in question. Lynis grays out components that are not available on the system, provided that their absence does not affect the security of the system as a whole.
The individual tests are divided into categories. If you launch the software as a normal user, Lynis skips some checks that can only be executed if you are root. The program outputs messages to point out the skipped test routines. After the test results, Lynis also displays a hardening index and shows potential for improvement. Lynis makes suggestions based on the individual test categories on how you can upgrade problematic settings to improve your system's security. You can open these tips by following the links in your web browser (Figure 2).
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.
News
-
Canonical Bumps LTS Support to 12 years
If you're worried that your Ubuntu LTS release won't be supported long enough to last, Canonical has a surprise for you in the form of 12 years of security coverage.
-
Fedora 40 Beta Released Soon
With the official release of Fedora 40 coming in April, it's almost time to download the beta and see what's new.
-
New Pentesting Distribution to Compete with Kali Linux
SnoopGod is now available for your testing needs
-
Juno Computers Launches Another Linux Laptop
If you're looking for a powerhouse laptop that runs Ubuntu, the Juno Computers Neptune 17 v6 should be on your radar.
-
ZorinOS 17.1 Released, Includes Improved Windows App Support
If you need or desire to run Windows applications on Linux, there's one distribution intent on making that easier for you and its new release further improves that feature.
-
Linux Market Share Surpasses 4% for the First Time
Look out Windows and macOS, Linux is on the rise and has even topped ChromeOS to become the fourth most widely used OS around the globe.
-
KDE’s Plasma 6 Officially Available
KDE’s Plasma 6.0 "Megarelease" has happened, and it's brimming with new features, polish, and performance.
-
Latest Version of Tails Unleashed
Tails 6.0 is based on Debian 12 and includes GNOME 43.
-
KDE Announces New Slimbook V with Plenty of Power and KDE’s Plasma 6
If you're a fan of KDE Plasma, you'll be thrilled to hear they've announced a new Slimbook with an AMD CPU and the latest version of KDE Plasma desktop.
-
Monthly Sponsorship Includes Early Access to elementary OS 8
If you want to get a glimpse of what's in the pipeline for elementary OS 8, just set up a monthly sponsorship to help fund its continued existence.