Privileged guest-to-host code execution via fwctl overflow
Published Aug 1, 2023 · Updated Feb 13, 2025
Buffer overflow in bhyve's fwctl interface in FreeBSD 13.1 and 13.2 allows guest OS users to execute code in the host process. The fwctl state machine copies a guest-supplied string into bhyve process memory without enforcing the destination buffer's length. Exploitation requires privileged guest software, an amd64 host, and a guest launched with -l bootrom; Capsicum constrains the resulting host-process code.
Summary
What happened
Buffer overflow in bhyve's fwctl interface in FreeBSD 13.1 and 13.2 allows guest OS users to execute code in the host process. The fwctl state machine copies a guest-supplied string into bhyve process memory without enforcing the destination buffer's length. Exploitation requires privileged guest software, an amd64 host, and a guest launched with -l bootrom; Capsicum constrains the resulting host-process code.
The record
- CVE
- CVE-2023-3494
- Published
- Aug 1, 2023
- Updated
- Feb 13, 2025
- Vendor
- The FreeBSD Project
- Product
- FreeBSD
- Classifications
- CWE-120, T1068
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Aug 1, 2023CVE publishedPublication date reported by the CVE source.
- Feb 13, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=13.1-RELEASE <13.1-RELEASE-p9
- Affected versionversion=13.2-RELEASE <13.2-RELEASE-p2
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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