CVE-2022-39957highCWE-693

CVE-2022-39957: high-severity vulnerability in OWASP ModSecurity Core Rule Set

Response body bypass in OWASP ModSecurity Core Rule Set via a specialy crafted charset in the HTTP Accept header

Published · Updated

21Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 7.3epss 1.0%
exploitation probability
1.0%top 38% of all CVEs
observed exploitation
nono source reports it
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Affected products
OWASP · ModSecurity Core Rule Set
Related CVEs — OWASP ModSecurity Core Rule Set

In the same product, most dangerous first.

CVE-2022-39955HIGHPartial rule set bypass in OWASP ModSecurity Core Rule Set by submitting a specially crafted HTTP Content-Type headerEPSS 1.4%CVE-2022-39958HIGHResponse body bypass in OWASP ModSecurity Core Rule Set via repeated HTTP Range header submission with a small byte rangeEPSS 1.2%CVE-2022-39956HIGHPartial rule set bypass in OWASP ModSecurity Core Rule Set for HTTP multipart requests using character encoding in the Content-Type or Content-Transfer-Encoding headerEPSS 1.2%
References
https://coreruleset.org/20220919/crs-version-3-3-3-and-3-2-2-covering-several-cves/https://lists.debian.org/debian-lts-announce/2023/01/msg00033.htmlhttps://lists.debian.org/debian-lts-announce/2025/08/msg00004.htmlhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HL2L2GF7GOCWPMJZDUE5OXDSXHGG3XUJ/https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PD56EAYNGB6E6QQH62LAYCONOP6OH5DZ/https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YPQ6CCMX3MU4A7MTCGQJA7VMJW3IQDXV/https://security.gentoo.org/glsa/202305-25