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modsecurity-crs — security advisory

Type: advisorySources: OSVAdvisory ID: DEBIAN-CVE-2022-39955

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.

Products
modsecurity-crs
Affected versions
Not specified
Fixed versions
3.3.4-1
CVEs
CVE-2022-39955
Confirmed fixed CVEs
Not specified
Updated in this feed
30 Oct 2026, 14:58 UTC · Revision 1

Source evidence

DEBIAN-CVE-2022-39955

core-osv · Original source

Published 20 Sept 2022, 07:15 UTC

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.

osv:DEBIAN-CVE-2022-39955

modsecurity-crs

Fixed versions: 3.3.4-1

modsecurity-crs

Fixed versions: 3.3.4-1

modsecurity-crs

Fixed versions: 3.3.4-1

Complete source record
{
  "id": "70ac3bbb2bebc0c0be963f5cc4a9136c1b0c272c20e8f705fce4140d98b5c714",
  "url": "https://osv.dev/vulnerability/DEBIAN-CVE-2022-39955",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "DEBIAN-CVE-2022-39955",
    "summary": "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.",
    "evidence": "osv:DEBIAN-CVE-2022-39955",
    "products": [
      {
        "name": {
          "value": "modsecurity-crs",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "3.3.4-1",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "modsecurity-crs",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "3.3.4-1",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "modsecurity-crs",
          "evidence": "/affected/2/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "3.3.4-1",
            "evidence": "/affected/2/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "critical",
    "structured": {
      "id": "DEBIAN-CVE-2022-39955",
      "aliases": [
        "DEBIAN-CVE-2022-39955"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "3.3.4-1"
                }
              ]
            }
          ],
          "package": {
            "name": "modsecurity-crs",
            "purl": "pkg:deb/debian/modsecurity-crs?arch=source&distro=bookworm",
            "ecosystem": "Debian:12"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2022-39955.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "3.3.4-1"
                }
              ]
            }
          ],
          "package": {
            "name": "modsecurity-crs",
            "purl": "pkg:deb/debian/modsecurity-crs?arch=source&distro=trixie",
            "ecosystem": "Debian:13"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2022-39955.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "3.3.4-1"
                }
              ]
            }
          ],
          "package": {
            "name": "modsecurity-crs",
            "purl": "pkg:deb/debian/modsecurity-crs?arch=source&distro=forky",
            "ecosystem": "Debian:14"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2022-39955.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        }
      ],
      "modified": "2026-10-15T08:02:41.473971339Z",
      "provider": "osv",
      "upstream": [
        "CVE-2022-39955"
      ],
      "references": [
        "https://security-tracker.debian.org/tracker/CVE-2022-39955"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2022-39955",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 323979,
  "published_at": "2022-09-20T07:15:12.153+00:00"
}