dbcve.org
FreeBSDOperating system

CVE-2022-23087

HIGH · 8.8 CVSS v3.1 Published 2024-02-15
Fix available
A fix is available. Upgrade to 12.3 or later.
See remediation →
90/100
Remediation priority · Urgent
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
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.

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 · high confidence

A memory corruption vulnerability exists in the e1000 network adapter emulation within bhyve. When checksum offload is requested, the guest can provide an unvalidated offset value that allows writing beyond the bounds of an on-stack buffer, enabling a malicious VM to corrupt host memory and potentially achieve code execution in the bhyve process context.

MitigationApply any available bhyve patches that add validation for guest-provided checksum offsets; ensure Capsicum sandbox is enabled; consider network isolation for untrusted VMs.

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:>= 12.0, < 12.3= 12.3= 13.0

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
Low
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/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. Check FreeBSD host version
    Run 'freebsd-version' or 'uname -r' and compare the output against the affected ranges: >= 12.0, < 12.3; = 12.3; = 13.0
    Affected if The version matches any of the listed affected versions (12.0 through 12.2, exactly 12.3, or exactly 13.0)
  2. Verify bhyve is installed
    Run 'which bhyve' or check if bhyve binaries exist in /usr/sbin/bhyve
    Affected if bhyve is installed on the system
  3. Identify running VMs using e1000 NIC emulation
    For each running VM, examine the bhyve command line or VM configuration files (typically in /vm or /etc/bhyve) and look for '-s' slot definitions containing 'e1000'
    Affected if Any VM is configured with an e1000 network adapter (e.g., 'e1000:0'=tap0')
  4. Confirm checksum offload processing
    Review VM network configuration; checksum offload is typically enabled by default in guest operating systems and processed by the bhyve e1000 emulation when the VM requests it
    Affected if The guest VM has checksum offload enabled (default behavior for most guest OSes) and uses an e1000 adapter

A system is affected if it runs bhyve with any e1000 network adapter on FreeBSD versions 12.0-12.2, 12.3, or 13.0, as the unvalidated checksum offset vulnerability exists in the e1000 emulation for these versions.

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 12.3 or later
Fixed in 12.3
Interim mitigation

Apply any available bhyve patches that add validation for guest-provided checksum offsets; ensure Capsicum sandbox is enabled; consider network isolation for untrusted VMs.

Recommended fix High confidence

FreeBSD 12.4-RELEASE or FreeBSD 13.1-RELEASE (depending on major version)

  1. Check current FreeBSD version with: uname -a or freebsd-version -u
  2. For FreeBSD 12.x systems: Upgrade to FreeBSD 12.4-RELEASE or later (13.0 and 12.3 are affected; 12.4+ contains the fix)
  3. For FreeBSD 13.x systems: Upgrade to FreeBSD 13.1-RELEASE or later (13.0 is affected; 13.1+ contains the fix)
  4. Follow FreeBSD upgrade procedure: https://www.freebsd.org/releases/13.1R/installation/
  5. After upgrade, verify bhyve version includes the fix by checking the e1000 emulator code or referring to FreeBSD security advisory
  6. Test that bhyve VMs with e1000 network adapters function correctly post-upgrade
Caveat Standard FreeBSD upgrade risks apply - ensure backups and test in non-production environment first; capsicum sandbox configuration may behave differently

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

Fix this in FreeBSD Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing8.0 h
  • Review / QA3.0 h
18.0 hours of engineering $3,060
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,896.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2022-23087 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2022-23087 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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