CVE-2018-6794

MEDIUM

Suricata < 4.0.4 - HTTP Detection Bypass via TCP Handshake Evasion

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2018-6794. PoCs published by Positive Technologies.

AI-analyzed exploit summary The exploit describes a TCP 3-way handshake bypass technique in Suricata IDS versions <4.0.4, allowing data injection before handshake completion to evade detection. A PoC server and traffic capture are referenced but not included in the provided code.

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.

Exploits (1)

exploitdb WRITEUP
by Positive Technologies · textdosmultiple
https://www.exploit-db.com/exploits/44247

The exploit describes a TCP 3-way handshake bypass technique in Suricata IDS versions <4.0.4, allowing data injection before handshake completion to evade detection. A PoC server and traffic capture are referenced but not included in the provided code.

Classification
Writeup 90%
Attack Type
Other
Complexity
Moderate
Reliability
Reliable
Target: Suricata <4.0.4
No auth needed
Prerequisites: Network access to inject TCP packets · Client and server in a controlled network environment
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (5)

Core 5
Core References
Mailing List, Third Party Advisory mailing-list x_refsource_mlist
https://lists.debian.org/debian-lts-announce/2018/12/msg00000.html
Third Party Advisory x_refsource_confirm
https://redmine.openinfosecfoundation.org/issues/2427
Exploit, Third Party Advisory, VDB Entry exploit x_refsource_exploit-db
https://www.exploit-db.com/exploits/44247/

Scores

CVSS v3 5.3
EPSS 0.2953
EPSS Percentile 98.0%
Attack Vector NETWORK
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Details

CWE
CWE-693
Status published
Products (2)
debian/debian_linux 8.0
suricata-ids/suricata < 4.0.4
Published Feb 07, 2018
Tracked Since Feb 18, 2026