Lynis Security Controls

FIRE-4520 - Configuration warnings in pf firewall


Lynis uses the built-in check of pf to determine if the configuration has any warnings. When the utility shows any, Lynis will trigger this control.



How to solve

Run pfctl in verbose mode (-vvv) and the -n option to check your configuration file. More extensive tests can be done with the Lynis Enterprise plugins and interface.

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Linux and Unix System Hardening

This information is provided as part of the Lynis community project. It is related to Lynis control FIRE-4520. All information should be considered as-is, without guarantees. Any advice or snippets should be tested before implementing in production environments.


Lynis is a technical security audit tool for Unix flavors like Linux, macOS, AIX, Solaris, and *BSD. It is open source software and free to use. The project has an active community, including open development via GitHub.

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