# CVE-2022-39955: modsecurity-crs: The OWASP ModSecurity Core Rule Set (CRS) is affected by a partial rule set bypass by submitting a specially crafted...

CVE-2022-39955 is fixed in modsecurity-crs on 1 platform, first by DEBIAN-CVE-2022-39955, released September 20, 2022. It is not reported as exploited. Patch Radar priority: Urgent.

- Web page: https://patchblox.com/security/cve/CVE-2022-39955
- Priority: Urgent
- CVSS: 9.8 (critical)
- EPSS: 0.0142
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 20, 2022

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | modsecurity-crs Debian 12.15 (bookworm) | 3.3.4-1 | [DEBIAN-CVE-2022-39955](https://patchblox.com/security/data/fix/linux/debian-cve-2022-39955.md) | Sep 20, 2022 |
| Linux | modsecurity-crs Debian 13.5 (trixie) | 3.3.4-1 | [DEBIAN-CVE-2022-39955](https://patchblox.com/security/data/fix/linux/debian-cve-2022-39955.md) | Sep 20, 2022 |
| Linux | modsecurity-crs Debian 14 | 3.3.4-1 | [DEBIAN-CVE-2022-39955](https://patchblox.com/security/data/fix/linux/debian-cve-2022-39955.md) | Sep 20, 2022 |

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