Vulnerability · Published Dec 16, 2021 · Assigned by mitre

CVE-2021-45098

High 7.5

In plain English

A high-severity security flaw in the suricata package (Alpine). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 2.0% (higher than 80% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)7.5High

Exploit odds (30 days)2.0%top 19.6% of all CVEs

Exploited in the wildNo reportsnot in CISA KEV

Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Alpine:v3.20	suricata	6.0.4-r0	ALPINE-CVE-2021-45098
Alpine:v3.21	suricata	6.0.4-r0	ALPINE-CVE-2021-45098
Alpine:v3.22	suricata	6.0.4-r0	ALPINE-CVE-2021-45098
Alpine:v3.23	suricata	6.0.4-r0	ALPINE-CVE-2021-45098
Alpine:v3.24	suricata	6.0.4-r0	ALPINE-CVE-2021-45098
Debian:13	suricata	1:6.0.4-1	DEBIAN-CVE-2021-45098
Debian:14	suricata	1:6.0.4-1	DEBIAN-CVE-2021-45098

Affected products (as reported)

Vendor	Product	Versions
n/a	n/a	n/a

References

https://github.com/OISF/suricata/releases x_refsource_MISC
https://redmine.openinfosecfoundation.org/issues/4710 x_refsource_MISC
https://forum.suricata.io/t/suricata-6-0-4-and-5-0-8-released/1942 x_refsource_MISC
https://github.com/OISF/suricata/commit/50e2b973eeec7172991bf8f544ab06fb782b97df x_refsource_MISC
https://lists.debian.org/debian-lts-announce/2025/03/msg00029.html