CVE-2022-39955

High

Description

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.

SeverityHigh
CVSS7.3
Exploit probability—
ProductOwasp Modsecurity Core Rule Set
PublishedSep 20, 2022
First seenSep 20, 2022

How to fix

Affected products

ProductAffected versionsFixed in
owasp owasp_modsecurity_core_rule_set3.0.0 ≤ v < 3.2.2, 3.3.0 ≤ v < 3.3.33.2.2, 3.3.3
fedoraproject fedora35, 36, 37—
debian debian_linux10.0—

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