CVE-2021-29631: Freebsd

High severity, CVSS 7.8. EPSS: 0.3% chance of exploitation in the next 30 days.

In FreeBSD 13.0-STABLE before n246941-20f96f215562, 12.2-STABLE before r370400, 11.4-STABLE before r370399, 13.0-RELEASE before p4, 12.2-RELEASE before p10, and 11.4-RELEASE before p13, certain VirtIO-based device models in bhyve failed to handle errors when fetching I/O descriptors. A malicious guest may cause the device model to operate on uninitialized I/O vectors leading to memory corruption, crashing of the bhyve process, and possibly arbitrary code execution in the bhyve process.

Affected products

• Freebsd Freebsd: version 11.4 only; version 12.2 only; version 13.0 only

Published 2021-08-30. Last modified 2026-06-17.