bhyve(8) privileged guest escape via TPM device passthrough

published 2024-09-05 2 y ago modified 2026-06-17 4 mo ago also EUVD-2024-39279

cvss: 8.4; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 15%
public exploits: 0; none known

Malicious software running in a guest VM can exploit the buffer overflow to achieve code execution on the host in the bhyve userspace process, which typically runs as root. Note that bhyve runs in a Capsicum sandbox, so malicious code is constrained by the capabilities available to the bhyve process.

Patch / fix

fixed in 1

FreeBSD FreeBSD 14.0_p10, 14.1_p4, p4, p10

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 2 y ago (2024-09-05)

Exploit prediction

0.24% chance of exploitation in the next 30 days, higher than 15% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	8.4	CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA	3.1	8.4	CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

FreeBSD FreeBSD

Classification

Weakness

CWE-125 Out-of-bounds Read
CWE-787 Out-of-bounds Write
CWE-1285 Improper Validation of Specified Index, Position, or Offset in Input

References

Sources

CVE List CVE-2024-41928
NVD CVE-2024-41928

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary