CVE-2021-45098

Public Exploit

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.

7.5

CVSS

Severity: High

CVSS 3.1 •

CVSS 2.0 •

EPSS 0.52%

Vendor Advisory suricata.io Vendor Advisory openinfosecfoundation.org

Affected: n/a n/a

References

Link	Tags
https://github.com/OISF/suricata/releases	third party advisory release notes
https://redmine.openinfosecfoundation.org/issues/4710	issue tracking patch vendor advisory exploit
https://forum.suricata.io/t/suricata-6-0-4-and-5-0-8-released/1942	release notes vendor advisory
https://github.com/OISF/suricata/commit/50e2b973eeec7172991bf8f544ab06fb782b97df	third party advisory patch

Frequently Asked Questions

What is the severity of CVE-2021-45098?: CVE-2021-45098 has been scored as a high severity vulnerability.
How to fix CVE-2021-45098?: To fix CVE-2021-45098, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-45098 being actively exploited in the wild?: It is possible that CVE-2021-45098 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~1% probability that this vulnerability will be exploited by malicious actors in the next 30 days.

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