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No exploitation reportedFix available

CVE-2021-45098

No exploitation reported by the sources we read.

  • Published2021-12-16

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

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.

Timeline

dates in UTC
  1. 2021-12-1605:15CVE publishedNVD

Versions per branch

NVD
Debian debian linux
BranchAffectedFixed in
9.0= 9.0no fix published
10.0= 10.0no fix published
11.0= 11.0no fix published
Oisf suricata
BranchAffectedFixed in
6.0< 6.0.46.0.4

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • suricataUbuntu:18.04:LTSall versions · no fixed version listed
  • suricataUbuntu:16.04:LTSall versions · no fixed version listed
  • suricataDebian:14all versions · fixed in 1:6.0.4-1
  • suricataDebian:13all versions · fixed in 1:6.0.4-1
  • suricataDebian:11all versions · fixed in 1:6.0.1-3+deb11u1
  • suricataCleanStartall versions · fixed in 6.0.4-r0
  • suricataAlpine:v3.24all versions · fixed in 6.0.4-r0
  • suricataAlpine:v3.23all versions · fixed in 6.0.4-r0

8 more package ranges on OSV.dev

Vendor advisories

  • CVE-2021-45098 Red Hat Product Security

    suricata: bypass of payload detection on TCP RST with options of MD5header

Full record on NVD

Fix

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Published
2021-12-16
Last Modified
2026-06-17
NVD status
Modified
GitHub Advisory
GHSA-cfcf-x7x2-gpf8

Frequently asked questions

What is 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.

Is CVE-2021-45098 actively exploited?

Active exploitation of CVE-2021-45098 has not been confirmed. Its EPSS score was 2.0% on 2026-11-08, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-45098?

CVE-2021-45098 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

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Sources for this record