CRS – OWASP ModSecurity Core Rule Set

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.The Core Rule Set provides protection against many common attack categories, including:SQL Injection (SQLi)Cross Site Scripting (XSS)Local File Inclusion (LFI)Remote File Inclusion (RFI)Remote Code Execution (RCE)PHP Code InjectionHTTP Protocol Violations    HTTPoxyShellshockSession FixationScanner DetectionMetadata/Error LeakagesProject Honey Pot BlacklistGeoIP Country BlockingNew Features in CRS 3CRS 3 includes many coverage improvements, plus the following new features:Over 90% reduction of false alerts in a default installA user-defined Paranoia Level to enable additional strict checksApplication-specific exclusions for WordPress Core and DrupalSampling mode runs the CRS on a user-defined percentage of trafficSQLi/XSS parsing using libinjection embedded in ModSecurityFor a full list of changes in this release, see the CHANGES document.InstallationCRS 3 requires an Apache/IIS/Nginx web server with ModSecurity 2.8.0 or higher.Download CRS.git clone download, copy crs-setup.conf.example to crs-setup.conf. Optionally edit this file to configure your CRS settings. Then include the files in your webserver configuration:Include /…/crs-setup.confInclude /…/rules/*.confFor detailed installation instructions, see the INSTALL document. Also review the CHANGES and KNOWN_BUGS documents.You can update the rule set using the included script util/ False Positives and Advanced FeaturesAdvanced features are explained in the crs-setup.conf and the rule files themselves. The crs-setup.conf file is generally a very good entry point to explore the features of the CRS.We are trying hard to reduce the number of false positives (false alerts) in the default installation. But sooner or later, you may encounter false positives nevertheless.Christian Folini’s tutorials on installing ModSecurity, configuring the CRS and handling false positives provide in-depth information on these topics.Core TeamChaim Sanders (csanders-git) – Project LeadWalter Hop (lifeforms) – Core DeveloperChristian Folini (Twitter: @ChrFolini, GitHub: dune73) – Core DeveloperDownload Owasp-Modsecurity-CRS