SARA / Free Tools / CVE / CVE-2022-39957

CVE-2022-39957 — The OWASP ModSecurity Core Rule Set (CRS) is affected by a response body bypass

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 res

CVSS
7.3 HIGH
EPSS
0.09% (top 75.40%)
CWE
CWE-693
Published
2022-09-20T00:00:00.000Z
Last modified
2025-11-03T19:27:31.661Z
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

01What is this vulnerability?

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…

02Affected products

VendorProductVersions
OWASPModSecurity Core Rule Set3.0.x, 3.1.x, unspecified, unspecified

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

09References

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