CVE-2022-23087: Bhyve e82545 device emulation out-of-bounds write

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-02-15 · updated 2026-06-17
Weakness: CWE-787

Description

The e1000 network adapters permit a variety of modifications to an Ethernet packet when it is being transmitted. These include the insertion of IP and TCP checksums, insertion of an Ethernet VLAN header, and TCP segmentation offload ("TSO"). The e1000 device model uses an on-stack buffer to generate the modified packet header when simulating these modifications on transmitted packets. When checksum offload is requested for a transmitted packet, the e1000 device model used a guest-provided value to specify the checksum offset in the on-stack buffer. The offset was not validated for certain packet types. A misbehaving bhyve guest could overwrite memory in the bhyve process on the host, possibly leading to code execution in the host context. The bhyve process runs in a Capsicum sandbox, which (depending on the FreeBSD version and bhyve configuration) limits the impact of exploiting this issue.

Affected products

FreeBSD: from 12.0 before 12.3; 12.3, 12.3-p1, 12.3-p2, 12.3-p3, 12.3-p4, 13.0 (+21) — fixed in 12.3

How to fix

Upgrade to a fixed version: FreeBSD 12.3. Check the vendor advisory for mitigations.

References

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