What’s Vulnerable › Vulnerabilities

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

• Severity: medium (CVSS 6.2 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2024-03-01 · updated 2026-06-17
• Weakness: CWE-367

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.

Affected products

• OpenBSD: before 7.4; 7.4, 7.4-errata_001, 7.4-errata_002, 7.4-errata_003, 7.4-errata_004, 7.4-errata_005 (+3) — fixed in 7.4

How to fix

Upgrade to a fixed version: OpenBSD 7.4. Check the vendor advisory for mitigations.

References

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