Useful Tools

There are many first and third party tools that help with ModSecurity and CRS development. The most useful ones are listed here. Get in touch if you think something is missing.


The backend server used by the CRS test suite. It is especially useful for testing response rules, as desired responses can be freely specified.


A Coraza plus reverse proxy container for testing. Makes it possible to easily test CRS with Coraza in a similar way to testing CRS using the Apache and Nginx Docker containers.

A local CRS installation can be included using directives in a directives.conf file like so:

Include ../coreruleset/crs-setup.conf.example
Include ../coreruleset/rules/*.conf


The CRS developer’s toolbelt. Documentation lives at crs-toolchain.


Framework for Testing WAFs in Go. A Go-based rewrite of the original Python FTW project.

Official CRS Maintained Docker Images

ModSecurity CRS Docker Image

A Docker image supporting the latest stable CRS release on:

  • the latest stable ModSecurity v2 on Apache
  • the latest stable ModSecurity v3 on Nginx


A ModSecurity config parser. Makes it possible to modify SecRules en masse, for example adding a tag to every rule in a rule set simultaneously.

msc_retest (RE test)

An invaluable tool for testing how regular expressions behave and perform in both mod_security2 (the Apache module) and libModSecurity (ModSecurity v3).


A tool for testing and finding regular expressions that are vulnerable to regular expression denial of service attacks (ReDoS).