ModSecurity

ModSecurity / libModSecurity 3.0.0 to 3.0.11 is affected by a WAF bypass for path-based payloads submitted via specially crafted request URLs. ModSecurity v3 decodes percent-encoded characters present in request URLs before it separates the URL path component from the optional…

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…

A buffer overflow in modsecurity v3.0.12 allows attackers to cause a Denial of Service (DoS) via a crafted input inserted into the name parameter. NOTE: this is disputed by the Supplier because it cannot be reproduced. Also, the product's documentation indicates that it is not…

ModSecurity 3.x through 3.0.5 mishandles excessively nested JSON objects. Crafted JSON objects with nesting tens-of-thousands deep could result in the web server being unable to service legitimate requests. Even a moderately large (e.g., 300KB) HTTP request can occupy one of the…

Trustwave ModSecurity 3.x through 3.0.4 allows denial of service via a special request. NOTE: The discoverer reports "Trustwave has signaled they are disputing our claims." The CVE suggests that there is a security issue with how ModSecurity handles regular expressions that can…

ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. From 3.0.0 to before 3.0.15, there is an unhandled exception (std::out_of_range) caused by unsigned integer underflow in libmodsecurity3 if the user (administrator)…

ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. Libmodsecurity is one component of the ModSecurity v3 project. A segmentation fault occurs when a rule using the t:hexDecode transformation inspects a query string…

ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. In versions 2.9.8 to before 2.9.11, an empty XML tag can cause a segmentation fault. If SecParseXmlIntoArgs is set to On or OnlyArgs, and the request type is…

An issue was discovered in OWASP ModSecurity Core Rule Set (CRS) through 3.1.0. /rules/REQUEST-933-APPLICATION-ATTACK-PHP.conf allows remote attackers to cause a denial of service (ReDOS) by entering a specially crafted string with $a# at the beginning and nested repetition…

An issue was discovered in OWASP ModSecurity Core Rule Set (CRS) through 3.1.0. /rules/REQUEST-933-APPLICATION-ATTACK-PHP.conf allows remote attackers to cause a denial of service (ReDOS) by entering a specially crafted string with set_error_handler# at the beginning and nested…

An issue was discovered in OWASP ModSecurity Core Rule Set (CRS) through 3.1.0. /rules/REQUEST-933-APPLICATION-ATTACK-PHP.conf allows remote attackers to cause a denial of service (ReDOS) by entering a specially crafted string with next# at the beginning and nested repetition…

An issue was discovered in OWASP ModSecurity Core Rule Set (CRS) through 3.1.0. /rules/REQUEST-932-APPLICATION-ATTACK-RCE.conf allows remote attackers to cause a denial of service (ReDOS) by entering a specially crafted string with nested repetition operators. NOTE: the software…

An issue was discovered in OWASP ModSecurity Core Rule Set (CRS) through 3.1.0. /rules/REQUEST-942-APPLICATION-ATTACK-SQLI.conf allows remote attackers to cause a denial of service (ReDOS) by entering a specially crafted string with nested repetition operators.

ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. From 3.0.0 through 3.0.15, the t:utf8toUnicode transformation in src/actions/transformations/utf8_to_unicode.cc produces wrong output on i386 architecture because…

The mod_security2 module before 2.7.0 for the Apache HTTP Server allows remote attackers to bypass rules, and deliver arbitrary POST data to a PHP application, via a multipart request in which an invalid part precedes the crafted data.

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.

Interpretation conflict in ModSecurity (mod_security) 2.1.0 and earlier allows remote attackers to bypass request rules via application/x-www-form-urlencoded POST data that contains an ASCIIZ (0x00) byte, which mod_security treats as a terminator even though it is still…

ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. In versions 2.9.11 and below, an attacker can override the HTTP response’s Content-Type, which could lead to several issues depending on the HTTP scenario. For…

ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. Versions prior to 2.9.10 contain a denial of service vulnerability similar to GHSA-859r-vvv8-rm8r/CVE-2025-47947. The `sanitiseArg` (and `sanitizeArg` - this is the…

ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. Versions up to and including 2.9.8 are vulnerable to denial of service in one special case (in stable released versions): when the payload's content type is…

Incorrect handling of '\0' bytes in file uploads in ModSecurity before 2.9.7 may allow for Web Application Firewall bypasses and buffer over-reads on the Web Application Firewall when executing rules that read the FILES_TMP_CONTENT collection.

In ModSecurity before 2.9.6 and 3.x before 3.0.8, HTTP multipart requests were 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.

An issue was discovered in OWASP ModSecurity Core Rule Set (CRS) 3.0.2. Use of X.Filename instead of X_Filename can bypass some PHP Script Uploads rules, because PHP automatically transforms dots into underscores in certain contexts where dots are invalid.

The ModSecurity module before 2.7.4 for the Apache HTTP Server allows remote attackers to cause a denial of service (NULL pointer dereference, process crash, and disk consumption) via a POST request with a large body and a crafted Content-Type header.

ModSecurity before 2.7.3 allows remote attackers to read arbitrary files, send HTTP requests to intranet servers, or cause a denial of service (CPU and memory consumption) via an XML external entity declaration in conjunction with an entity reference, aka an XML External Entity…

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…

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.

Multiple unspecified vulnerabilities in the ModSecurity (aka mod_security) module 2.5.0 through 2.5.5 for the Apache HTTP Server, when SecCacheTransformations is enabled, allow remote attackers to cause a denial of service (daemon crash) or bypass the product's functionality via…

Off-by-one buffer overflow in ModSecurity (mod_security) 1.7.4 for Apache 2.x, when SecFilterScanPost is enabled, allows remote attackers to execute arbitrary code via crafted POST requests.

Heap-based buffer overflow in the sec_filter_out function in mod_security 1.7RC1 through 1.7.1 in Apache 2 allows remote attackers to execute arbitrary code via a server side script that sends a large amount of data.