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suricata — security advisory

Type: advisorySources: OSVAdvisory ID: DEBIAN-CVE-2021-45098

An issue was discovered in Suricata before 6.0.4. It is possible to bypass/evade any HTTP-based signature by faking an RST TCP packet with random TCP options of the md5header from the client side. After the three-way handshake, it's possible to inject an RST ACK with a random TCP md5header option. Then, the client can send an HTTP GET request with a forbidden URL. The server will ignore the RST ACK and send the response HTTP packet for the client's request. These packets will not trigger a Suricata reject action.

Products
suricata
Affected versions
Not specified
Fixed versions
1:6.0.4-1
CVEs
CVE-2021-45098
Confirmed fixed CVEs
Not specified
Updated in this feed
1 Nov 2026, 01:51 UTC · Revision 1

Source evidence

DEBIAN-CVE-2021-45098

core-osv · Original source

Published 16 Dec 2021, 05:15 UTC

An issue was discovered in Suricata before 6.0.4. It is possible to bypass/evade any HTTP-based signature by faking an RST TCP packet with random TCP options of the md5header from the client side. After the three-way handshake, it's possible to inject an RST ACK with a random TCP md5header option. Then, the client can send an HTTP GET request with a forbidden URL. The server will ignore the RST ACK and send the response HTTP packet for the client's request. These packets will not trigger a Suricata reject action.

osv:DEBIAN-CVE-2021-45098

suricata

Fixed versions: 1:6.0.4-1

suricata

Fixed versions: 1:6.0.4-1

Complete source record
{
  "id": "d00869b2cedf4f63c3dc67e499a7af3471e5b71658a3229cfb4f4e8b2bce94fc",
  "url": "https://osv.dev/vulnerability/DEBIAN-CVE-2021-45098",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "DEBIAN-CVE-2021-45098",
    "summary": "An issue was discovered in Suricata before 6.0.4. It is possible to bypass/evade any HTTP-based signature by faking an RST TCP packet with random TCP options of the md5header from the client side. After the three-way handshake, it's possible to inject an RST ACK with a random TCP md5header option. Then, the client can send an HTTP GET request with a forbidden URL. The server will ignore the RST ACK and send the response HTTP packet for the client's request. These packets will not trigger a Suricata reject action.",
    "evidence": "osv:DEBIAN-CVE-2021-45098",
    "products": [
      {
        "name": {
          "value": "suricata",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "1:6.0.4-1",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "suricata",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "1:6.0.4-1",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "DEBIAN-CVE-2021-45098",
      "aliases": [
        "DEBIAN-CVE-2021-45098"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "1:6.0.4-1"
                }
              ]
            }
          ],
          "package": {
            "name": "suricata",
            "purl": "pkg:deb/debian/suricata?arch=source&distro=trixie",
            "ecosystem": "Debian:13"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-45098.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "1:6.0.4-1"
                }
              ]
            }
          ],
          "package": {
            "name": "suricata",
            "purl": "pkg:deb/debian/suricata?arch=source&distro=forky",
            "ecosystem": "Debian:14"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-45098.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        }
      ],
      "modified": "2026-10-23T18:05:06.616278597Z",
      "provider": "osv",
      "upstream": [
        "CVE-2021-45098"
      ],
      "references": [
        "https://security-tracker.debian.org/tracker/CVE-2021-45098"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2021-45098",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 424259,
  "published_at": "2021-12-16T05:15:08.727+00:00"
}