Libmodsecurity is one component of the ModSecurity v3 project. The library codebase serves as an interface to ModSecurity Connectors taking in web traffic and applying traditional ModSecurity processing. A bug that exists only in Libmodsecurity3 version 3.0.13 means that, in 3.0.13, Libmodsecurity3 can't decode encoded HTML entities if they contains leading zeroes. Version 3.0.14 contains a fix. No known workarounds are available.

Trustwave ModSecurity 3.x before 3.0.10 has Inefficient Algorithmic Complexity.

Trustwave ModSecurity 3.0.5 through 3.0.8 before 3.0.9 allows a denial of service (worker crash and unresponsiveness) because some inputs cause a segfault in the Transaction class for some configurations.

A vulnerability was found in ModSecurity. This issue occurs when HTTP multipart requests are incorrectly parsed and could bypass the Web Application Firewall. NOTE: This is related to CVE-2022-39956, but can be considered independent changes to the ModSecurity (C language) codebase.

In ModSecurity before 2.9.7, FILESTMPCONTENT sometimes lacked the complete content. This can lead to a Web Application Firewall bypass.

https://github.com/SpiderLabs/ModSecurity/pull/2857/commits/4324f0ac59f8225aa44bc5034df60dbeccd1d334 https://github.com/SpiderLabs/ModSecurity/releases/tag/v2.9.7 https://github.com/SpiderLabs/ModSecurity/pull/2857

ModSecurity 3.x before 3.0.4 mishandles key-value pair parsing, as demonstrated by a "string index out of range" error and worker-process crash for a "Cookie: =abc" header.

DISPUTED ModSecurity 3.0.0 has XSS via an onerror attribute of an IMG element. NOTE: a third party has disputed this issue because it may only apply to environments without a Core Rule Set configured.

apache2/modsecurity.c in ModSecurity before 2.7.6 allows remote attackers to bypass rules by using chunked transfer coding with a capitalized Chunked value in the Transfer-Encoding HTTP header.

ModSecurity before 2.6.6, when used with PHP, does not properly handle single quotes not at the beginning of a request parameter value in the Content-Disposition field of a request with a multipart/form-data Content-Type header, which allows remote attackers to bypass filtering rules and perform other attacks such as cross-site scripting (XSS) attacks. NOTE: this vulnerability exists because of an incomplete fix for CVE-2009-5031.

The multipart processor in ModSecurity before 2.5.9 allows remote attackers to cause a denial of service (crash) via a multipart form datapost request with a missing part header name, which triggers a NULL pointer dereference.

The PDF XSS protection feature in ModSecurity before 2.5.8 allows remote attackers to cause a denial of service (Apache httpd crash) via a request for a PDF file that does not use the GET method.