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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| OWASP | ModSecurity Core Rule Set | 3.0.x, 3.1.x, unspecified – ≤ 3.2.1, unspecified – ≤ 3.3.2 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | modsecurity-crs | 3.3.4-1 | — |
| Debian 13 | modsecurity-crs | 3.3.4-1 | — |
| Debian 12 | modsecurity-crs | 3.3.4-1 | — |
| Debian 11 | modsecurity-crs | 3.3.4-1~deb11u1 | DLA-4265-1 |
| Debian 10 | modsecurity-crs | 3.2.3-0+deb10u3 | DLA-3293-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | modsecurity-crs | No fix yet | — |
| Ubuntu 26.04 LTS | modsecurity-crs | No fix yet | — |
| Ubuntu 25.10 | modsecurity-crs | No fix yet | — |
| Ubuntu 24.04 LTS | modsecurity-crs | No fix yet | — |
| Ubuntu 22.04 LTS | modsecurity-crs | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | modsecurity-crs | No fix yet | — |
| Ubuntu 18.04 LTS | modsecurity-crs | No fix yet | — |
| Ubuntu 16.04 LTS | modsecurity-crs | No fix yet | — |
Advisories 3
- DLA-4265-1 modsecurity-crs - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-3293-1 modsecurity-crs - security update Debian Security (DSA / DLA) · Mar 9, 2026
- WID-SEC-2022-1653 Trustwave ModSecurity: Mehrere Schwachstellen BSI CERT-Bund (WID) · Aug 10, 2025
References
- https://coreruleset.org/20220919/crs-version-3-3-3-and-3-2-2-covering-several-cves/
- FEDORA-2022-90708b46e3 vendor-advisory
- FEDORA-2022-85a85c84b3 vendor-advisory
- FEDORA-2022-1fd73a5285 vendor-advisory
- [debian-lts-announce] 20230130 [SECURITY] [DLA 3293-1] modsecurity-crs security update mailing-list
- GLSA-202305-25 vendor-advisory