FreeBSD : FreeBSD -- bhyve(8) privileged guest escape via TPM device passthrough (56d76414-6b50-11ef-9a62-002590c1f29c)

high Nessus Plugin ID 206693

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Synopsis

The remote FreeBSD host is missing one or more security-related updates.

Description

The version of FreeBSD installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the 56d76414-6b50-11ef-9a62-002590c1f29c advisory.

bhyve can be configured to provide access to the host's TPM device, where it passes the communication through an emulated device provided to the guest. This may be performed on the command-line by starting bhyve with the `-l tpm,passthru,/dev/tpmX` parameters.
The MMIO handler for the emulated device did not validate the offset and size of the memory access correctly, allowing guests to read and write memory contents outside of the memory area effectively allocated.
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.

Tenable has extracted the preceding description block directly from the FreeBSD security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Update the affected packages.

Plugin Details

Severity: High

ID: 206693

File Name: freebsd_pkg_56d764146b5011ef9a62002590c1f29c.nasl

Version: 1.3

Type: local

Family: FreeBSD Local Security Checks

Published: 9/6/2024

Updated: 9/26/2024

Configuration: Enable paranoid mode

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.9

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5

Vector: CVSS2#AV:L/AC:L/Au:N/C:P/I:C/A:C

CVSS Score Source: CVE-2024-41928

CVSS v3

Risk Factor: High

Base Score: 8.4

Temporal Score: 7.3

Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:freebsd:freebsd

Required KB Items: Settings/ParanoidReport, Host/local_checks_enabled, Host/FreeBSD/release, Host/FreeBSD/pkg_info

Exploit Ease: No known exploits are available

Patch Publication Date: 9/5/2024

Vulnerability Publication Date: 9/5/2024

Reference Information

CVE: CVE-2024-41928

IAVA: 2024-A-0545-S

Detections

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