CVE-2021-29627

Severity: high (CVSS 7.8 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: 2021-04-07 · updated 2026-06-17
Weakness: CWE-415

Description

In FreeBSD 13.0-STABLE before n245050, 12.2-STABLE before r369525, 13.0-RC4 before p0, and 12.2-RELEASE before p6, listening socket accept filters implementing the accf_create callback incorrectly freed a process supplied argument string. Additional operations on the socket can lead to a double free or use after free.

Affected products

FreeBSD: from 12.0 before 12.2; 12.2, 12.2-p1, 12.2-p2, 13.0-beta1, 13.0-beta2, 13.0-beta3 (+4) — fixed in 12.2

How to fix

Upgrade to a fixed version: FreeBSD 12.2. Check the vendor advisory for mitigations.

References

https://security.FreeBSD.org/advisories/FreeBSD-SA-21:09.accept_filter.asc
https://security.netapp.com/advisory/ntap-20210423-0007/
https://security.FreeBSD.org/advisories/FreeBSD-SA-21:09.accept_filter.asc
https://security.netapp.com/advisory/ntap-20210423-0007/

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