9.8
CVSSv3

CVE-2022-39955

Published: 20/09/2022 Updated: 07/11/2023
CVSS v3 Base Score: 9.8 | Impact Score: 5.9 | Exploitability Score: 3.9
VMScore: 0

Vulnerability Summary

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.

Vulnerability Trend

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owasp owasp modsecurity core rule set

fedoraproject fedora 35

fedoraproject fedora 36

fedoraproject fedora 37

debian debian linux 10.0

Vendor Advisories

Debian Bug report logs - #1021137 modsecurity-crs: CVE-2022-39955 CVE-2022-39956 CVE-2022-39957 CVE-2022-39958 Package: src:modsecurity-crs; Maintainer for src:modsecurity-crs is Alberto Gonzalez Iniesta <agi@inittaborg>; Reported by: Moritz Mühlenhoff <jmm@inutilorg> Date: Sun, 2 Oct 2022 18:15:02 UTC Severity: ...
Description The MITRE CVE dictionary describes this issue as: 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-T ...