Bug 2131319 (CVE-2022-39957)

Summary:	CVE-2022-39957 mod_security_crs: Charset accept header field resulting in response rule set bypass
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 payload with a HTTP accept header field containing a charset that can't be decoded by the Web Application Firewall allows a response body bypass, resulting in access to restricted resources.	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:	2131320, 2131348, 2131349
Bug Blocks:	2128790

Description Guilherme de Almeida Suckevicz 2022-09-30 17:07:40 UTC

The OWASP ModSecurity Core Rule Set (CRS) is affected by a response body bypass. A client can issue an HTTP Accept header field containing an optional "charset" parameter in order to receive the response in an encoded form. Depending on the "charset", this response can not be decoded by the web application firewall. A restricted resource, access to which would ordinarily be detected, may therefore bypass detection. 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 17:07:55 UTC

Created mod_security_crs tracking bugs for this issue:

Affects: fedora-all [bug 2131320]