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FreeBSDOperating system

CVE-2016-1889

HIGH · 7.8 CVSS v3.0 Published 2017-02-15
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
80/100
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
Integer overflow in the bhyve hypervisor in FreeBSD 10.1, 10.2, 10.3, and 11.0 when configured with a large amount of guest memory, allows local users to gain privilege via a crafted device descriptor.

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

Integer overflow in the bhyve hypervisor's device descriptor handling code when configured with large guest memory allocations, allowing a local attacker to corrupt memory and escalate privileges.

MitigationApply FreeBSD security patches for CVE-2016-1889 to bhyve; alternatively, restrict local untrusted user access to bhyve instances and limit guest memory allocations below the overflow trigger threshold until patched.

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:= 10.1= 10.2= 10.3= 11.0

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
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/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 version
    Run `freebsd-version` or `uname -r` to determine the installed FreeBSD version
    Affected if The version is 10.1, 10.2, 10.3, or 11.0 exactly
  2. Verify bhyve is installed
    Run `which bhyve` or check the package with `pkg info bhyve`
    Affected if The bhyve hypervisor binary is present on the system
  3. Identify bhyve guest memory configurations
    Examine bhyve command lines, VM configuration files in /etc/bhyve or /var/vm, and running bhyve processes for memory allocation parameters (typically -m or --memory flags)
    Affected if Any VM is configured with large guest memory allocations (values that could cause an integer overflow in device descriptor handling)
  4. Check for active bhyve instances
    Use `ps aux | grep bhyve` or check for running VM processes
    Affected if There are running bhyve instances with large memory allocations on an affected FreeBSD version

A system is affected if it runs FreeBSD 10.1, 10.2, 10.3, or 11.0 with the bhyve hypervisor installed and has any VM configured with large guest memory allocations that trigger the integer overflow condition.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply FreeBSD security patches for CVE-2016-1889 to bhyve; alternatively, restrict local untrusted user access to bhyve instances and limit guest memory allocations below the overflow trigger threshold until patched.

Fix this in FreeBSD Scoped from the published advisory
  • Consultation3.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA3.0 h
18.0 hours of engineering $3,180
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

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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-2016-1889 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