Bug 2131315 (CVE-2022-39955)

Summary:	CVE-2022-39955 mod_security_crs: Multiple charsets defined in Content-Type header
Product:	[Other] Security Response	Reporter:	Guilherme de Almeida Suckevicz <gsuckevi>
Component:	vulnerability	Assignee:	Nobody <nobody>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	athmanem, luhliari
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	mod_security_crs 3.2.2, mod_security_crs 3.3.3	Doc Type:	If docs needed, set a value
Doc Text:	A flaw was found in the OWASP ModSecurity Core Rule Set. A specially crafted HTTP Content-Type header field allows an encoded payload bypass detection, which may be decoded in the back-end application.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2131316, 2131341, 2131342
Bug Blocks:	2128790

Description Guilherme de Almeida Suckevicz 2022-09-30 16:52:51 UTC

The OWASP ModSecurity Core Rule Set (CRS) is affected by a partial rule set bypass by submitting a specially crafted HTTP Content-Type header field that indicates multiple character encoding schemes. A vulnerable back-end can potentially be exploited by declaring multiple Content-Type "charset" names and therefore bypassing the configurable CRS Content-Type header "charset" allow list. An encoded payload can bypass CRS detection this way and may then be decoded by the backend. The legacy CRS versions 3.0.x and 3.1.x are affected, as well as the currently supported versions 3.2.1 and 3.3.2. Integrators and users are advised to upgrade to 3.2.2 and 3.3.3 respectively.

Reference:
https://coreruleset.org/20220919/crs-version-3-3-3-and-3-2-2-covering-several-cves/

Comment 1 Guilherme de Almeida Suckevicz 2022-09-30 16:53:05 UTC

Created mod_security_crs tracking bugs for this issue:

Affects: fedora-all [bug 2131316]