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GHA build v4.0/dev GHA build v3.3/dev GHA build v3.2/dev
OWASP Flagship CII Best Practices License

OWASP ModSecurity Core Rule Set (CRS)

The OWASP ModSecurity Core Rule Set (CRS) is a set of generic attack detection rules for use with ModSecurity or compatible web application firewalls. The CRS aims to protect web applications from a wide range of attacks, including the OWASP Top Ten, with a minimum of false alerts.

CRS Resources

Please see the OWASP ModSecurity Core Rule Set page to get introduced to the CRS and view resources on installation, configuration, and working with the CRS.

Contributing to the CRS

We strive to make the OWASP ModSecurity CRS accessible to a wide audience of beginner and experienced users. We are interested in hearing any bug reports, false-positive alert reports, evasions, usability issues, and suggestions for new detections.

Create an issue on GitHub to report a false positive or false negative (evasion). Please include your installed version and the relevant portions of your ModSecurity audit log. We will try and address your issue and potentially ask for additional information to reproduce your problem. Please also note that stale issues will be flagged and closed after 120 days. You can search for stale issues with the following search query.

Sign up for our Google Group to ask general usage questions and participate in discussions on the CRS. Also here you can find the archives for the previous mailing list.

Join the #coreruleset channel on OWASP Slack to chat about the CRS. (Click here to get an invitation if you are not yet registered on the OWASP slack. It's open to non-members too.)


Copyright (c) 2006-2020 Trustwave and contributors. All rights reserved.
Copyright (c) 2021-2023 Core Rule Set project. All rights reserved.

The OWASP ModSecurity Core Rule Set is distributed under Apache Software License (ASL) version 2. Please see the enclosed LICENSE file for full details.