Suricata before 4.0.4 is prone to an HTTP detection bypass...

Vulnerability Description

Suricata before 4.0.4 is prone to an HTTP detection bypass vulnerability in detect.c and stream-tcp.c. If a malicious server breaks a normal TCP flow and sends data before the 3-way handshake is complete, then the data sent by the malicious server will be accepted by web clients such as a web browser or Linux CLI utilities, but ignored by Suricata IDS signatures. This mostly affects IDS signatures for the HTTP protocol and TCP stream content; signatures for TCP packets will inspect such network traffic as usual.

References

• https://github.com/OISF/suricata/pull/3202/commits/e1ef57c848bbe4e567d5d4b66d346a742e3f77a1
• https://lists.debian.org/debian-lts-announce/2018/12/msg00000.html
• https://redmine.openinfosecfoundation.org/issues/2427
• https://suricata-ids.org/2018/02/14/suricata-4-0-4-available/
• https://www.exploit-db.com/exploits/44247/