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.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | suricata | 1:6.0.4-1 | — |
| Debian 13 | suricata | 1:6.0.4-1 | — |
| Debian 11 | suricata | 1:6.0.1-3+deb11u1 | DLA-4103-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | suricata | No fix yet | — |
| Ubuntu 16.04 LTS | suricata | No fix yet | — |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | suricata | 6.0.4-r0 | — |
| Alpine v3.23 | suricata | 6.0.4-r0 | — |
| Alpine v3.22 | suricata | 6.0.4-r0 | — |
| Alpine v3.21 | suricata | 6.0.4-r0 | — |
| Alpine v3.20 | suricata | 6.0.4-r0 | — |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | suricata | 6.0.4-r0 | — |
| Alpine v3.18 | suricata | 6.0.4-r0 | — |
| Alpine v3.17 | suricata | 6.0.4-r0 | — |
| Alpine v3.16 | suricata | 6.0.4-r0 | — |
| Alpine v3.15 | suricata | 6.0.4-r0 | — |
Advisories 1
- DLA-4103-1 suricata - security update Debian Security (DSA / DLA) · Mar 9, 2026