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lynis - Man Page

System and security auditing tool

Examples (TL;DR)


lynis [scan mode] [other options]


Lynis is a security auditing tool for Linux, macOS, and other systems based on UNIX. The tool checks the system and the software configuration, to see if there is any room for improvement the security defenses. All details are stored in a log file. Findings and other discovered data is stored in a report file. This can be used to compare differences between audits. Lynis can run interactively or as a cronjob. Root permissions (e.g. sudo) are not required, however provide more details during the audit.

The following system areas may be checked:

- Boot loader files

- Configuration files

- Software packages

- Directories and files related to logging and auditing

First Time Usage

When running Lynis for the first time, run: lynis audit system


audit <type>

Perform an audit of the selected type


Upload the available report data file

See Helpers section for more commands.

Scan Types

audit system

Performs a system audit, which is the most common audit.

audit system remote <host>

Provide commands to do a remote scan.

For more scan modes, see the helper utilities.


--auditor <name>

Define the name of the auditor/pentester. When a full name is used, add double quotes, like "Your Name".


Perform automatic scan with cron safe options (no colors, no questions, no breaks).


Display debug information to screen for troubleshooting purposes.


Display detailed information useful for developers when creating tests.


Perform the audit on a running or mounted system (see --rootdir)


Show available commands and most-used options.

--logfile </path/to/logfile>

Defines location and name of log file, instead of default /var/log/lynis.log.


Show the man page. Useful for systems that do not have the man page installed.


Disable colored output.


Redirect all logging information to /dev/null, prevents sensitive information to be written to disk.


Do not run any of the enabled plugins.


Run a non-privileged scan, usually used for penetration testing. Some of the tests will be skipped if they require root permissions.

--plugin-dir </path/to/plugins>

Define location where plugins can be found.

--profile <file>

Provide alternative profile to perform the scan.

--quick (-Q)

Do a quick scan (default: don't wait for user input).

--quiet (-q)

Run quietly and do not show anything to the screen. Will also enable quick mode.

--report-file <file>

Provide an alternative name for report file.


Optimize screen output for light backgrounds.

--tests TEST-IDs

Only run the specific test(s). When using multiple tests, add quotes around the line.

--tests-from-category <category>

Tests are only performed if they belong to the defined category. Use the command Ā 'show categories' to determine all valid options.

--tests-from-group <group>

Similar to --tests-from-category. Only perform tests from a particular group. Use 'show groups' to determine valid options.


Run from the current working directory.


Upload data to Lynis Enterprise server (profile option: upload=yes).


Show more details on screen, such as components that could not found. These details are hidden by default.


Wait for user to continue. This adds a break after each section (opposed of --quick).


Run quietly, except show warnings.

Multiple parameters are allowed, though some parameters can only be used together with others. When running Lynis without any parameters, help will be shown and the program will exit.


Lynis has special helpers to do certain tasks. This way the framework of Lynis is used, while at the same time storing most of the functionality in a separated file. This speeds up execution and keeps the code clean.


Run audit on the system or on other targets

configure <parameter>

Change or add settings to the config file

generate <parameter>

Generate specific details such as host IDs

show <parameter>

Show information, such as configuration and paths

update <parameter>

Perform activities regarding updating

To use a helper, run 'lynis' followed by the helper name.

Exit Codes

Lynis uses exit codes to signal any invoking script. Currently the following codes are used:


Program exited normally


Fatal error


An unknown parameter is used, or incomplete


Incorrect data encountered


Can't open file or directory


Lynis found 1 or more warnings or configurations errors (with error-on-warnings=yes)


Bugs can be reported via GitHub at https://github.com/CISOfy/lynis or via support@cisofy.com


Supporting documentation can be found via https://cisofy.com/support/


Lynis is licensed as GPLv3. The tool was created by Michael Boelen in 2007. Since 2013 its development has been taken over by CISOfy under the management of Michael Boelen. Plugins may have a different license.

Contact Information

Support requests and project related questions can be addressed via e-mail: lynis-dev@cisofy.com.


14 Feb 2020 1.32 Unix System Administrator's Manual