CVE-2022-39956
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.00%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 1.00% probability · 61th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-863, CWE-116
- Affected
- owasp/owasp modsecurity core rule set · fedoraproject/fedora · debian/debian linux
- Source
- vulnerability@ncsc.ch
References
- https://coreruleset.org/20220919/crs-version-3-3-3-and-3-2-2-covering-several-cves/Patch, Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2023/01/msg00033.htmlMailing List, Third Party Advisory
- https://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
- https://coreruleset.org/20220919/crs-version-3-3-3-and-3-2-2-covering-several-cves/Patch, Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2023/01/msg00033.htmlMailing List, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2025/08/msg00004.html
- https://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
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.