Vulnerability Description
The OWASP ModSecurity Core Rule Set (CRS) is affected by a partial rule set bypass for HTTP multipart requests by submitting a payload that uses a character encoding scheme via the Content-Type or the deprecated Content-Transfer-Encoding multipart MIME header fields that will not be decoded and inspected by the web application firewall engine and the rule set. The multipart payload will therefore bypass detection. A vulnerable backend that supports these encoding schemes can potentially be exploited. 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 upgrade to 3.2.2 and 3.3.3 respectively. The mitigation against these vulnerabilities depends on the installation of the latest ModSecurity version (v2.9.6 / v3.0.8).
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Owasp | Owasp Modsecurity Core Rule Set | >= 3.0.0, < 3.2.2 |
| Fedoraproject | Fedora | 35 |
| Debian | Debian Linux | 10.0 |
Related Weaknesses (CWE)
References
- https://coreruleset.org/20220919/crs-version-3-3-3-and-3-2-2-covering-several-cvPatchVendor Advisory
- https://lists.debian.org/debian-lts-announce/2023/01/msg00033.htmlMailing ListThird Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://security.gentoo.org/glsa/202305-25
- https://coreruleset.org/20220919/crs-version-3-3-3-and-3-2-2-covering-several-cvPatchVendor Advisory
- https://lists.debian.org/debian-lts-announce/2023/01/msg00033.htmlMailing ListThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2025/08/msg00004.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://security.gentoo.org/glsa/202305-25
FAQ
What is CVE-2022-39956?
CVE-2022-39956 is a vulnerability with a CVSS score of 7.3 (HIGH). The OWASP ModSecurity Core Rule Set (CRS) is affected by a partial rule set bypass for HTTP multipart requests by submitting a payload that uses a character encoding scheme via the Content-Type or the...
How severe is CVE-2022-39956?
CVE-2022-39956 has been rated HIGH with a CVSS base score of 7.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2022-39956?
Check the references section above for vendor advisories and patch information. Affected products include: Owasp Owasp Modsecurity Core Rule Set, Fedoraproject Fedora, Debian Debian Linux.