CVE-2019-18792

Name: CVE-2019-18792
Creator: NVD / NIST
Published: 2020-01-06T18:15:23.183+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.1/10EPSS 2.52%

Last modified Jun 17, 2026

CVE-2019-18792 is a critical-severity vulnerability rated 9.1/10 on the CVSS scale. An issue was discovered in Suricata 5.0.0. It is possible to bypass/evade any tcp based signature by overlapping a TCP segment with a fake FIN packet. EPSS estimates a 2.52% chance of exploitation in the next 30 days.

Description

An issue was discovered in Suricata 5.0.0. It is possible to bypass/evade any tcp based signature by overlapping a TCP segment with a fake FIN packet. The fake FIN packet is injected just before the PUSH ACK packet we want to bypass. The PUSH ACK packet (containing the data) will be ignored by Suricata because it overlaps the FIN packet (the sequence and ack number are identical in the two packets). The client will ignore the fake FIN packet because the ACK flag is not set. Both linux and windows clients are ignoring the injected packet.

Metrics

CVSS 3.1

9.1/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

EPSS Probability

2.52%

82.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-436

Affected Software

Vendor	Product	Versions
Oisf	Suricata	>= 4.1.5, < 4.1.6
Oisf	Suricata	5.0.0
Debian	Debian Linux	8.0

References

https://github.com/OISF/suricata/commit/1c63d3905852f746ccde7e2585600b2199cefb4bPatch, Third Party Advisory
https://github.com/OISF/suricata/commit/fa692df37a796c3330c81988d15ef1a219afc006Patch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/01/msg00032.htmlThird Party Advisory
https://redmine.openinfosecfoundation.org/issues/3324Exploit, Third Party Advisory
https://redmine.openinfosecfoundation.org/issues/3394Exploit, Third Party Advisory
https://github.com/OISF/suricata/commit/1c63d3905852f746ccde7e2585600b2199cefb4bPatch, Third Party Advisory
https://github.com/OISF/suricata/commit/fa692df37a796c3330c81988d15ef1a219afc006Patch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/01/msg00032.htmlThird Party Advisory
https://redmine.openinfosecfoundation.org/issues/3324Exploit, Third Party Advisory
https://redmine.openinfosecfoundation.org/issues/3394Exploit, Third Party Advisory

Timeline

Published: Jan 6, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-18792?

How severe is CVE-2019-18792?

CVE-2019-18792 has a CVSS score of 9.1/10 (CRITICAL severity). The EPSS model estimates a 2.52% probability of exploitation in the next 30 days.

How do I fix CVE-2019-18792?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2019-18792?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST