CVE-2022-39957 Response body bypass in OWASP ModSecurity Core Rule Set via a specialy crafted charset in the HTTP Accept header

What is CVE-2022-39957?

CVE-2022-39957 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 response body bypass. A client can issue an HTTP Accept header field containing an optional "charset" parameter in order to receive the response in an encoded form. Depending on the "charset", this response can not be decoded by the web application firewall. A restricted resource, access to which would ordinarily be detected, may therefore bypass detection. 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-116, CWE-693

Which versions are affected by CVE-2022-39957?

It affects 3 products.

Products include Debian Debian Linux, Fedoraproject Fedora, Owasp Owasp Modsecurity Core Rule Set.

How do I fix CVE-2022-39957?

Upgrade to a fixed version.

Is CVE-2022-39957 being exploited?

There is no known exploitation of CVE-2022-39957 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

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• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2022-39957, GHSA-cxqq-h5hh-jgq2, UBUNTU-CVE-2022-39957.