CVE catalog

CVE-2021-45098

DEBIAN-

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.

Severity: High · CVSS 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Published: Nov 12, 2021, 12:00:00 AM UTC
Updated: Sep 1, 2026, 8:04:34 PM UTC
Source: [NVD] · [CVE record]
EPSS: 1.96% · Oct 27, 2026

Projects and upstream resources

[suricata][Source-reported homepage]

Reported versions and fixes

Each observation applies to its named package, distribution, and release. Distribution backports can fix a vulnerability while retaining an older upstream version number.

Distribution / release	Package	Version	Status	Source
Ubuntu18.04	suricata	`3.2-2ubuntu3`	UnknownSource applicability is not established	[UBUNTU-CVE-2021-45098]Oct 24, 2025, 4:50:38 AM UTC
Ubuntu16.04	suricata	`2.0.10-1`	UnknownSource applicability is not established	[UBUNTU-CVE-2021-45098]Oct 24, 2025, 4:50:38 AM UTC
Ubuntu16.04	suricata	`2.0.10-2`	UnknownSource applicability is not established	[UBUNTU-CVE-2021-45098]Oct 24, 2025, 4:50:38 AM UTC
Ubuntu16.04	suricata	`2.0.11-1`	UnknownSource applicability is not established	[UBUNTU-CVE-2021-45098]Oct 24, 2025, 4:50:38 AM UTC
Ubuntu16.04	suricata	`2.0.8-1build1`	UnknownSource applicability is not established	[UBUNTU-CVE-2021-45098]Oct 24, 2025, 4:50:38 AM UTC
Ubuntu16.04	suricata	`2.0.9-1`	UnknownSource applicability is not established	[UBUNTU-CVE-2021-45098]Oct 24, 2025, 4:50:38 AM UTC
Ubuntu16.04	suricata	`3.0-1`	UnknownSource applicability is not established	[UBUNTU-CVE-2021-45098]Oct 24, 2025, 4:50:38 AM UTC
Debian14	suricata	`1:6.0.4-1`	UnknownSource applicability is not established	[DEBIAN-CVE-2021-45098]Oct 23, 2026, 6:05:06 PM UTC
Debian13	suricata	`1:6.0.4-1`	UnknownSource applicability is not established	[DEBIAN-CVE-2021-45098]Oct 23, 2026, 6:05:06 PM UTC
Debian11	suricata	`1:6.0.1-3`	UnknownSource applicability is not established	[DLA-4103-1]Mar 9, 2026, 1:18:14 AM UTC
Debian11	suricata	`1:6.0.1-3+deb11u1`	UnknownSource applicability is not established	[DLA-4103-1]Mar 9, 2026, 1:18:14 AM UTC

Provider details and historical evidence

Distribution / release	Package	Version	Status	Source
Debian11	suricata	`1:6.0.1-3`	UnknownSource applicability is not established	[DLA-4103-1]Mar 9, 2026, 1:18:14 AM UTC
Debian11	suricata	`1:6.0.1-3+deb11u1`	UnknownSource applicability is not established	[DLA-4103-1]Mar 9, 2026, 1:18:14 AM UTC
Debian13	suricata	`1:6.0.4-1`	UnknownSource applicability is not established	[DEBIAN-CVE-2021-45098]Oct 23, 2026, 6:05:06 PM UTC
Debian14	suricata	`1:6.0.4-1`	UnknownSource applicability is not established	[DEBIAN-CVE-2021-45098]Oct 23, 2026, 6:05:06 PM UTC
Ubuntu16.04	suricata	`2.0.10-1`	UnknownSource applicability is not established	[UBUNTU-CVE-2021-45098]Oct 24, 2025, 4:50:38 AM UTC
Ubuntu16.04	suricata	`2.0.10-2`	UnknownSource applicability is not established	[UBUNTU-CVE-2021-45098]Oct 24, 2025, 4:50:38 AM UTC
Ubuntu16.04	suricata	`2.0.11-1`	UnknownSource applicability is not established	[UBUNTU-CVE-2021-45098]Oct 24, 2025, 4:50:38 AM UTC
Ubuntu16.04	suricata	`2.0.8-1build1`	UnknownSource applicability is not established	[UBUNTU-CVE-2021-45098]Oct 24, 2025, 4:50:38 AM UTC
Ubuntu16.04	suricata	`2.0.9-1`	UnknownSource applicability is not established	[UBUNTU-CVE-2021-45098]Oct 24, 2025, 4:50:38 AM UTC
Ubuntu16.04	suricata	`3.0-1`	UnknownSource applicability is not established	[UBUNTU-CVE-2021-45098]Oct 24, 2025, 4:50:38 AM UTC
Ubuntu18.04	suricata	`3.2-2ubuntu3`	UnknownSource applicability is not established	[UBUNTU-CVE-2021-45098]Oct 24, 2025, 4:50:38 AM UTC

Original provider fields

{
  "package_releases": [],
  "fixed_versions": [],
  "distribution_packages": [
    {
      "name": "suricata",
      "distro": "debian",
      "ranges": [
        {
          "type": "ECOSYSTEM",
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1:6.0.4-1"
            }
          ]
        }
      ],
      "release": "13",
      "versions": [],
      "ecosystem": "deb",
      "provider_url": "https://osv.dev/vulnerability/DEBIAN-CVE-2021-45098",
      "fixed_version": "1:6.0.4-1",
      "provider_source": "pypi",
      "provider_record_id": "DEBIAN-CVE-2021-45098",
      "provider_updated_at": "2026-10-23T18:05:06.616278597Z",
      "applicability_unknown": true
    },
    {
      "name": "suricata",
      "distro": "debian",
      "ranges": [
        {
          "type": "ECOSYSTEM",
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1:6.0.4-1"
            }
          ]
        }
      ],
      "release": "14",
      "versions": [],
      "ecosystem": "deb",
      "provider_url": "https://osv.dev/vulnerability/DEBIAN-CVE-2021-45098",
      "fixed_version": "1:6.0.4-1",
      "provider_source": "pypi",
      "provider_record_id": "DEBIAN-CVE-2021-45098",
      "provider_updated_at": "2026-10-23T18:05:06.616278597Z",
      "applicability_unknown": true
    },
    {
      "name": "suricata",
      "distro": "debian",
      "ranges": [
        {
          "type": "ECOSYSTEM",
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1:6.0.1-3+deb11u1"
            }
          ]
        }
      ],
      "release": "11",
      "versions": [
        "1:6.0.1-3"
      ],
      "ecosystem": "deb",
      "provider_url": "https://osv.dev/vulnerability/DLA-4103-1",
      "fixed_version": "1:6.0.1-3+deb11u1",
      "provider_source": "pypi",
      "provider_record_id": "DLA-4103-1",
      "provider_updated_at": "2026-03-09T01:18:14.108597Z",
      "applicability_unknown": true
    },
    {
      "name": "suricata",
      "distro": "ubuntu",
      "ranges": [
        {
          "type": "ECOSYSTEM",
          "events": [
            {
              "introduced": "0"
            }
          ]
        }
      ],
      "release": "16.04",
      "versions": [
        "2.0.8-1build1",
        "2.0.9-1",
        "2.0.10-1",
        "2.0.10-2",
        "2.0.11-1",
        "3.0-1"
      ],
      "ecosystem": "deb",
      "provider_url": "https://osv.dev/vulnerability/UBUNTU-CVE-2021-45098",
      "fixed_version": "",
      "provider_source": "pypi",
      "provider_record_id": "UBUNTU-CVE-2021-45098",
      "provider_updated_at": "2025-10-24T04:50:38Z",
      "applicability_unknown": true
    },
    {
      "name": "suricata",
      "distro": "ubuntu",
      "ranges": [
        {
          "type": "ECOSYSTEM",
          "events": [
            {
              "introduced": "0"
            }
          ]
        }
      ],
      "release": "18.04",
      "versions": [
        "3.2-2ubuntu3"
      ],
      "ecosystem": "deb",
      "provider_url": "https://osv.dev/vulnerability/UBUNTU-CVE-2021-45098",
      "fixed_version": "",
      "provider_source": "pypi",
      "provider_record_id": "UBUNTU-CVE-2021-45098",
      "provider_updated_at": "2025-10-24T04:50:38Z",
      "applicability_unknown": true
    }
  ]
}

OpenFactory catalog packages

Matching against OpenFactory catalog package versions is in progress.

[Debian 13 (Trixie)]

[suricata]Unknown
Details (4)
- 1:7.0.10-1+deb13u4 · amd64 · trixie
  Fixed · Fixed: 1:6.0.4-1
  pypi · suricata · debian · 13
- 1:7.0.10-1+deb13u4 · arm64 · trixie
  Fixed · Fixed: 1:6.0.4-1
  pypi · suricata · debian · 13
- 1:8.0.6-1~bpo13+1 · amd64 · trixie-backports
  Fixed · Fixed: 1:6.0.4-1
  pypi · suricata · debian · 13
- 1:8.0.6-1~bpo13+1 · arm64 · trixie-backports
  Fixed · Fixed: 1:6.0.4-1
  pypi · suricata · debian · 13

Observed: Oct 23, 2026, 6:03:51 PM UTC

References

[FIRST EPSS] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX]