What’s Vulnerable › Vulnerabilities

CVE-2023-52558: OpenBSD 7.4 and 7.3 m_split() network buffer kernel crash

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.7% 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-131

Description

In OpenBSD 7.4 before errata 002 and OpenBSD 7.3 before errata 019, a network buffer that had to be split at certain length that could crash the kernel after receiving specially crafted escape sequences.

Affected products

• OpenBSD: before 7.3; 7.3, 7.3-errata_001, 7.3-errata_002, 7.3-errata_003, 7.3-errata_004, 7.3-errata_005 (+15) — fixed in 7.3

How to fix

Upgrade to a fixed version: OpenBSD 7.3. Check the vendor advisory for mitigations.

References

• https://ftp.openbsd.org/pub/OpenBSD/patches/7.3/common/019_msplit.patch.sig
• https://ftp.openbsd.org/pub/OpenBSD/patches/7.4/common/002_msplit.patch.sig
• https://github.com/openbsd/src/commit/7b4d35e0a60ba1dd4daf4b1c2932020a22463a89
• https://ftp.openbsd.org/pub/OpenBSD/patches/7.3/common/019_msplit.patch.sig
• https://ftp.openbsd.org/pub/OpenBSD/patches/7.4/common/002_msplit.patch.sig
• https://github.com/openbsd/src/commit/7b4d35e0a60ba1dd4daf4b1c2932020a22463a89

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