Blog

CRS Repository at New Location

We have successfully migrated our GitHub repository to a new location at https://github.com/coreruleset/coreruleset Trustwave SpiderLabs hosted the OWASP ModSecurity Core Rule Set project under their umbrella for many years. They acted as stewards of our project and also directed it via the former lead Ryan Barnett. Yet as a formally independent OWASP project, it is …

CRS Repository at New Location Read More »

CVE-2019-19886 – HIGH – DoS against libModSecurity 3

The ModSecurity 3.0.x release line suffers from a Denial of Service vulnerability after triggering a segmentation fault on the webserver when parsing a malformed cookie header. All users of ModSecurity 3.0.0 – 3.0.3 should update to ModSecurity 3.0.4 as soon as possible. ModSecurity 2.x is not affected. The CVSS score for the vulnerability is 7.5 …

CVE-2019-19886 – HIGH – DoS against libModSecurity 3 Read More »

Running a few dozens of new magic XSS payloads against CRS 3.2

Earlier today, Gareth Heyes presented a very interesting talk with dozens of new XSS payloads at the OWASP GlobalAppSec conference in Amsterdam. The CRS developers in the audience immediately started to try out the payloads, but Gareth was so quick they lost track… But being the helpful person he is, he published the slides during …

Running a few dozens of new magic XSS payloads against CRS 3.2 Read More »

Announcement: OWASP ModSecurity Core Rule Set Version 3.2.0

The OWASP ModSecurity Core Rule Set team is proud to announce the general availability of the OWASP ModSecurity Core Rule Set Version 3.2.0. The new release is available for download at https://coreruleset.org/installation/ This release represents a very big step forward in terms of both capabilities and protections including: Improved compatibility with ModSecurity 3.x Improved CRS …

Announcement: OWASP ModSecurity Core Rule Set Version 3.2.0 Read More »

How the CRS protects the vulnerable web application Pixi by OWASP DevSlop

How could the functionality of a WAF be better demonstrated than with a vulnerable web application? In this blog post I introduce Pixi, an intentionally vulnerable web application by the OWASP project DevSlop. I show its known vulnerabilities and examine how the CRS protects against these vulnerabilities. What is Pixi? Pixi is a deliberately vulnerable …

How the CRS protects the vulnerable web application Pixi by OWASP DevSlop Read More »

Announcement: OWASP ModSecurity Core Rule Set Version 3.2.0-RC2

The OWASP ModSecurity Core Rule Set team is proud to announce the general availability of release candidate 2 for the upcoming CRS v3.2.0. The new release is available at https://github.com/coreruleset/coreruleset/archive/v3.2.0-rc2.zip https://github.com/coreruleset/coreruleset/archive/v3.2.0-rc2.tar.gz This release represents a very big step forward in terms of both capabilities and protections including: Improved compatibility with ModSecurity 3.x Improved CRS docker …

Announcement: OWASP ModSecurity Core Rule Set Version 3.2.0-RC2 Read More »

How the CRS optimizes regular expressions

As many of you have noticed, the Core Rule Set contains very complex regular expressions. See for example rule 942480: (?i:(?:\b(?:(?:s(?:elect\b.{1,100}?\b(?:(?:(?:length|count)\b.{1,100}?|.*?\bdump\b.*)\bfrom|to(?:p\b.{1,100}?\bfrom|_(?:numbe|cha)r)|(?:from\b.{1,100}?\bwher|data_typ)e|instr)|ys_context)|in(?:to\b\W*?\b(?:dump|out)file|sert\b\W*?\binto|ner\b\W*?\bjoin)|… These regular expressions are assembled from a list of simpler regular expressions for efficiency reasons. See regexp-942480.data for the source expressions which were combined to form this expression. A single optimized regular expression test …

How the CRS optimizes regular expressions Read More »

Announcement: OWASP ModSecurity Core Rule Set Version 3.1.1

The OWASP ModSecurity Core Rule Set team is pleased to announce the CRS release v3.1.1. This is a minor release fixing a Regular Expression Denial of Service weakness (CVE-2019-11387) as well as some minor bugs and false positives. The CVE is only affecting users of the libModSecurity 3 release line and only under special circumstances. …

Announcement: OWASP ModSecurity Core Rule Set Version 3.1.1 Read More »