dbcve.org
FreeBSDOperating system

CVE-2024-32668

HIGH · 8.2 CVSS v3.1 Published 2024-09-05
Fix available
A fix is available. Upgrade to 13.3 or later.
See remediation →
84/100
Remediation priority · High
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
An insufficient boundary validation in the USB code could lead to an out-of-bounds write on the heap, with data controlled by the caller. A malicious, privileged software running in a guest VM can exploit the vulnerability 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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

A heap-based out-of-bounds write vulnerability exists in bhyve's USB code due to insufficient boundary validation. A malicious, privileged guest VM can trigger this flaw to achieve code execution on the host within the bhyve userspace process, which typically runs as root. The Capsicum sandbox constrains the impact by limiting available capabilities.

MitigationApply the vendor patch for CVE-2024-32668 to the bhyve hypervisor. Until patched, minimize exposure by restricting USB passthrough to untrusted guests and monitoring for suspicious VM activity.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
FreeBSDOperating system
Affected:>= 13.0, < 13.3= 13.3= 13.4= 14.0= 14.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
High
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify FreeBSD host version
    Run `freebsd-version -k` or `uname -r` to get the kernel version
    Affected if The version is any of: 13.0, 13.1, 13.2, 13.3, 13.4, 14.0, or 14.1 (versions 13.0 through 14.1 inclusive are affected, except 13.3 which is also affected per the '=' notation)
  2. Verify bhyve is installed
    Run `which bhyve` or check for the bhyve binary at `/usr/sbin/bhyve`
    Affected if bhyve is installed on the system (the vulnerability exists in the bhyve binary itself)
  3. Identify VMs using USB passthrough
    Review VM configuration files in `/var/vm/` or wherever VM configs are stored, looking for USB device entries (such as '-s x,x,ehci' or '-s x,x,xhci' USB controller lines, or USB device mappings)
    Affected if Any VM configuration includes USB controller or device passthrough (the USB emulation code containing the flaw is only invoked when USB passthrough is configured for a guest)
  4. Check for running bhyve processes with USB hardware
    Run `ps aux | grep bhyve` and examine command-line arguments for USB-related flags or review VM runtime configurations
    Affected if Any bhyve process is currently running with USB hardware passed to a guest VM (the vulnerable code path is active)
  5. Review USB device assignment logs
    Check system logs (via `dmesg` or `/var/log/messages`) for USB device attachment events to bhyve guests, or examine bhyve audit logs if enabled
    Affected if USB devices have been attached to guest VMs (indicating the vulnerable USB emulation code has been exercised)

A system is affected if it runs any FreeBSD version from 13.0 through 14.1 inclusive, has bhyve installed, and has at least one VM configured with USB passthrough enabled.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 13.3 or later
Fixed in 13.3
Interim mitigation

Apply the vendor patch for CVE-2024-32668 to the bhyve hypervisor. Until patched, minimize exposure by restricting USB passthrough to untrusted guests and monitoring for suspicious VM activity.

Recommended fix Moderate confidence

FreeBSD 14.1 or FreeBSD 13.5 (whichever branch is applicable)

  1. 1. Identify the current FreeBSD version using 'freebsd-version -u' or 'uname -a'
  2. 2. For systems running FreeBSD 14.0: Upgrade to FreeBSD 14.1 or later stable release
  3. 3. For systems running FreeBSD 13.3 or 13.4: Upgrade to FreeBSD 13.5 or later (or 14.1)
  4. 4. For systems running 13.0-13.2: Upgrade to FreeBSD 13.5 or later (or 14.1)
  5. 5. After upgrade, verify the bhyve process is updated by checking 'pkg info bhyve' or reviewing the changelog for security fixes
  6. 6. Ensure the system is rebooted or bhyve is restarted to load the patched binaries
Caveat Upgrade to major releases carries standard risks; review FreeBSD release notes for any configuration or compatibility changes

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in FreeBSD Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing8.0 h
  • Review / QA4.0 h
24.0 hours of engineering $4,160
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Scan for this in your stack

Free · runs locally
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2024-32668 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data