CVE-2022-39955 Partial rule set bypass in OWASP ModSecurity Core Rule Set by submitting a specially crafted HTTP Content-Type header
Attackers can bypass ModSecurity CRS protections by crafting HTTP Content-Type headers with multiple charsets, allowing malicious payloads to reach the backend.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-39955?
CVE-2022-39955 is a high-severity vulnerability in Debian Debian Linux, published on 20 Sep 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-863
Which versions are affected by CVE-2022-39955?
It affects 3 products.
Products include Debian Debian Linux, Fedoraproject Fedora, Owasp Owasp Modsecurity Core Rule Set.
How do I fix CVE-2022-39955?
Upgrade to a fixed version.
Is CVE-2022-39955 being exploited?
There is no known exploitation of CVE-2022-39955 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as DEBIAN-CVE-2022-39955, GHSA-x6xv-j46p-v597, UBUNTU-CVE-2022-39955.