Vulnerability 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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Oisf | Suricata | < 6.0.4 |
| Debian | Debian Linux | 9.0 |
References
- https://forum.suricata.io/t/suricata-6-0-4-and-5-0-8-released/1942Release NotesVendor Advisory
- https://github.com/OISF/suricata/commit/50e2b973eeec7172991bf8f544ab06fb782b97dfPatchThird Party Advisory
- https://github.com/OISF/suricata/releasesRelease NotesThird Party Advisory
- https://redmine.openinfosecfoundation.org/issues/4710ExploitIssue TrackingPatch
- https://forum.suricata.io/t/suricata-6-0-4-and-5-0-8-released/1942Release NotesVendor Advisory
- https://github.com/OISF/suricata/commit/50e2b973eeec7172991bf8f544ab06fb782b97dfPatchThird Party Advisory
- https://github.com/OISF/suricata/releasesRelease NotesThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2025/03/msg00029.html
- https://redmine.openinfosecfoundation.org/issues/4710ExploitIssue TrackingPatch
FAQ
What is CVE-2021-45098?
CVE-2021-45098 is a vulnerability with a CVSS score of 7.5 (HIGH). 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. Aft...
How severe is CVE-2021-45098?
CVE-2021-45098 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2021-45098?
Check the references section above for vendor advisories and patch information. Affected products include: Oisf Suricata, Debian Debian Linux.