SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2023-3494

The fwctl driver implements a state machine which is executed when a bhyve guest accesses certain x86 I/O ports.

HIGH 8.8EPSS 0.23%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.23%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

The fwctl driver implements a state machine which is executed when a bhyve guest accesses certain x86 I/O ports. The interface lets the guest copy a string into a buffer resident in the bhyve process' memory. A bug in the state machine implementation can result in a buffer overflowing when copying this string. Malicious, privileged 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, mitigated by the capabilities assigned through the Capsicum sandbox available to the bhyve process.

CVSS 3.1
8.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS
0.23% probability · 14th percentile
CISA KEV
Not listed
Weakness
CWE-120
Affected
freebsd/freebsd
Source
secteam@freebsd.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.