What’s Vulnerable › Vulnerabilities

CVE-2018-6794

• Severity: medium (CVSS 5.3 v3.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 23.7% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2018-02-07 · updated 2026-06-17
• Weakness: CWE-693

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.

Affected products

• Debian Linux: 8.0
• Suricata-Ids Suricata: before 4.0.4 — fixed in 4.0.4

How to fix

Upgrade to a fixed version: Suricata-Ids Suricata 4.0.4. Check the vendor advisory for mitigations.

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/
• 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/

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