CVE-2022-39956 Security feature bypass in ModSecurity Core Rule Set
Attackers can bypass ModSecurity Core Rule Set detection for multipart requests using specific character encodings, 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-2022-39956?
CVE-2022-39956 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 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).
Which versions are affected by CVE-2022-39956?
It affects 3 products.
Products include Debian Debian Linux, Fedoraproject Fedora, Owasp Owasp Modsecurity Core Rule Set.
How do I fix CVE-2022-39956?
Upgrade to a fixed version.
Is CVE-2022-39956 being exploited?
There is no known exploitation of CVE-2022-39956 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as DEBIAN-CVE-2022-39956, GHSA-5xc6-pmr2-qj78, UBUNTU-CVE-2022-39956.