CVE-2022-39955
mod_security_crs: Multiple charsets defined in Content-Type header
Severity by source
Trivy's own label is CRITICAL. Rated critical by NVD. Rated lower by Red Hat (medium).
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.
Affected packages and fixed versions
| Source | Package | Fixed in |
|---|---|---|
| debian 10 | modsecurity-crs | 3.2.3-0+deb10u3 |
| debian 11 | modsecurity-crs | 3.3.4-1~deb11u1 |
| debian 12 | modsecurity-crs | 3.3.4-1 |
| debian 13 | modsecurity-crs | 3.3.4-1 |
| debian 14 | modsecurity-crs | 3.3.4-1 |
| echo | modsecurity-crs | 3.3.4-1 |
| rapidfort alma 8 | mod_security_crs | no fix listed |
| rapidfort alma 9 | mod_security_crs | no fix listed |
| rapidfort Red Hat 9 | mod_security_crs | no fix listed |
| Red Hat | mod_security_crs | no fix listed |
References
- https://access.redhat.com/security/cve/CVE-2022-39955
- https://coreruleset.org/20220919/crs-version-3-3-3-and-3-2-2-covering-several-cves/
- https://github.com/advisories/GHSA-x6xv-j46p-v597
- https://lists.debian.org/debian-lts-announce/2023/01/msg00033.html
- https://lists.debian.org/debian-lts-announce/2025/08/msg00004.html
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/HL2L2GF7GOCWPMJZDUE5OXDSXHGG3XUJ/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PD56EAYNGB6E6QQH62LAYCONOP6OH5DZ/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/YPQ6CCMX3MU4A7MTCGQJA7VMJW3IQDXV/