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, its 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 clients request. These packets will not trigger a Suricata reject action.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Suricata | Oisf | * | 6.0.4 (excluding) |
| Suricata | Ubuntu | bionic | * |
| Suricata | Ubuntu | trusty | * |
| Suricata | Ubuntu | upstream | * |
| Suricata | Ubuntu | xenial | * |
References
- https://forum.suricata.io/t/suricata-6-0-4-and-5-0-8-released/1942
- https://github.com/OISF/suricata/commit/50e2b973eeec7172991bf8f544ab06fb782b97df
- https://github.com/OISF/suricata/releases
- https://redmine.openinfosecfoundation.org/issues/4710
- https://forum.suricata.io/t/suricata-6-0-4-and-5-0-8-released/1942
- https://github.com/OISF/suricata/commit/50e2b973eeec7172991bf8f544ab06fb782b97df
- https://github.com/OISF/suricata/releases
- https://lists.debian.org/debian-lts-announce/2025/03/msg00029.html
- https://redmine.openinfosecfoundation.org/issues/4710