Lynis 2.3.2 - Security Auditing Tool for Unix/Linux Systems

We are excited to announce this major release of auditing tool Lynis. Several big changes have been made to core functions of Lynis. These changes are the next of simplification improvements we made. There is a risk of breaking your existing configuration.

Lynis is an open source security auditing tool. Used by system administrators, security professionals, and auditors, to evaluate the security defenses of their Linux and UNIX-based systems. It runs on the host itself, so it performs more extensive security scans than vulnerability scanners.

Supported operating systems

The tool has almost no dependencies, therefore it runs on almost all Unix based systems and versions, including:
  • AIX
  • FreeBSD
  • HP-UX
  • Linux
  • Mac OS
  • NetBSD
  • OpenBSD
  • Solaris
  • and others
It even runs on systems like the Raspberry Pi and several storage devices!

Installation optional

Lynis is light-weight and easy to use. Installation is optional: just copy it to a system, and use "./lynis audit system" to start the security scan. It is written in shell script and released as open source software (GPL). 

How it works

Lynis performs hundreds of individual tests, to determine the security state of the system. The security scan itself consists of performing a set of steps, from initialization the program, up to the report.

  1. Determine operating system
  2. Search for available tools and utilities
  3. Check for Lynis update
  4. Run tests from enabled plugins
  5. Run security tests per category
  6. Report status of security scan
Besides the data displayed on screen, all technical details about the scan are stored in a log file. Any findings (warnings, suggestions, data collection) are stored in a report file.

Opportunistic scanning

Lynis scanning is opportunistic: it uses what it can find.
For example if it sees you are running Apache, it will perform an initial round of Apache related tests. When during the Apache scan it also discovers a SSL/TLS configuration, it will perform additional auditing steps on that. While doing that, it then will collect discovered certificates, so they can be scanned later as well.

In-depth security scans

By performing opportunistic scanning, the tool can run with almost no dependencies. The more it finds, the deeper the audit will be. In other words, Lynis will always perform scans which are customized to your system. No audit will be the same!

Use cases

Since Lynis is flexible, it is used for several different purposes. Typical use cases for Lynis include:
  • Security auditing
  • Compliance testing (e.g. PCI, HIPAA, SOx)
  • Vulnerability detection and scanning
  • System hardening

Resources used for testing

Many other tools use the same data files for performing tests. Since Lynis is not limited to a few common Linux distributions, it uses tests from standards and many custom ones not found in any other tool.
  • Best practices
  • CIS
  • NIST
  • NSA
  • OpenSCAP data
  • Vendor guides and recommendations (e.g. Debian Gentoo, Red Hat)

Lynis Plugins

lugins enable the tool to perform additional tests. They can be seen as an extension (or add-on) to Lynis, enhancing its functionality. One example is the compliance checking plugin, which performs specific tests only applicable to some standard.


Categories and Groups

Tests are now grouped by their focus area and named 'groups' accordingly. Besides groups, each test will belong to a category (performance, privacy, or security).
Commands: lynis show categories, lynis show groups Options: --tests-from-category, --tests-from-group
Note: You might need to change your scripts if you previously defined the group of tests to scan.

A new 'strict' option is available in the profiles and by default enabled for the initialization phases of Lynis. It will perform a strict code check for the tests, to detect any uninitialized variables, improving code quality.


With 'lynis update check' you can now check for updates. This is the preferred new method.
The command 'lynis show changelog' allows reviewing the changes. Optionally a release can be specified as additional argument.


Initial translation for German has been contributed by Kai Raven. The Italian translation by Stefano Marty (stefanomarty). Hungarian translation by Zoltan Paldi (paldiz)


Parsing of the profiles has been improved, which prevented some settings from overriding default settings.


  • AUTH-9212 - Added prerequisite to log
  • AUTH-9216 - Simplified test and make it more efficient
  • AUTH-9218 - Clean ups and improve readability
  • AUTH-9226 - Style, text, and removed warning
  • AUTH-9228 - Provide just a suggestion instead of warning
  • AUTH-9268 - Improve test for readability
  • AUTH-9328 - Test /etc/profile.d for umask setting
  • AUTH-9406 - Readability and code style changes
  • CONT-8102 - Determine if all Docker tests should be performed
  • DBS-1880 - Initial support for Redis server
  • HTTP-6720 - Readability improvement of test
  • KRNL-5830 - Readability and style improvements, ignore rescue images
  • MAIL-8818 - Style and refactoring
  • PHP-2211 - Readability improvement and code style changes
  • PHP-2374 - Changed text and cleanups
  • PHP-2376 - Log result to log file instead of report
  • PKGS-7383 - Simplified test
  • PKGS-7388 - Style and readability improvements
  • TIME-3106 - Corrected string to test for status
  • TOOL-5102 - Split of fail2ban tests
  • TOOL-5104 - Test for enabled fail2ban jails


Translation of Spanish (es) added Proper display of text strings when accented characters are used More text strings added


  • Added bold and header as new colors
  • Changed header and footer of screen output
  • Allow atomic tests to be skipped (e.g. SSH-7408)
  • Extended tests database with category (lynis show tests)
  • By default Lynis will now run in 'quick mode' and not break after each section. You can get this behavior by adding the --wait option.


  • RemoveColors - New test to clear colors
  • DisplayError - Display error on screen in uniform format and colors Use an optional exit code to quit the program
  • SkipAtomicTest - This function is now properly working with lowercase strings


Several controls on the website are added or updated, including:

  • FILE-6344
  • FINT-4315
  • FINT-4402
  • HTTP-6714
  • MACF-6234
  • NAME-4018
  • NAME-4402
  • PHP-2374
  • PROC-3612
  • TIME-3106

Lynis 2.3.2 - Security Auditing Tool for Unix/Linux Systems Lynis 2.3.2 - Security Auditing Tool for Unix/Linux Systems Reviewed by Zion3R on 12:30 AM Rating: 5