CVE-2016-3221
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 · uneditedThe kernel-mode drivers in Microsoft Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, and Windows 10 Gold and 1511 allow local users to gain privileges via a crafted application, aka "Win32k Elevation of Privilege Vulnerability," a different vulnerability than CVE-2016-3218.
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 confidenceWin32k.sys kernel-mode driver elevation of privilege vulnerability (CVE-2016-3221) allowing local authenticated users to execute arbitrary code with elevated privileges via a crafted application. Different vulnerability from CVE-2016-3218 but same component.
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 dataall versions= 1511all versionsall versionsall versionsall versions= r2all versions= r2all versionsCVSS 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
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/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 checksWork through these to decide whether this CVE applies to you.
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Identify Windows versionRun 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' to determine the Windows edition and versionAffected if Version is Windows Vista, 7, 8.1, 10, Rt 8.1, Server 2008, Server 2012, or Server 2012 R2 (any edition)
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Locate Win32k.sys fileFind the win32k.sys file in the system directory (typically C:\Windows\System32\drivers\win32k.sys)Affected if File exists on the system (it is present in all affected Windows versions)
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Check Win32k.sys versionRight-click win32k.sys, select Properties, then view the File Version attribute; or run 'powershell (Get-Item C:\Windows\System32\drivers\win32k.sys).VersionInfo'Affected if The file version is older than the patched version for MS16-061 (the unpatched versions contain the vulnerability)
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Verify MS16-061 update installationRun 'powershell Get-HotFix -Id "3147458"' or check Windows Update history for security update KB3147458Affected if The MS16-061 security update (KB3147458) is NOT installed on the system
The system is vulnerable if it runs any affected Windows version (Vista, 7, 8.1, 10, Rt 8.1, Server 2008/2012) AND lacks the MS16-061 (KB3147458) security update.
Generated from the published advisory. Verify against your own configuration.
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 dataApply Microsoft security update (MS16-061) to all affected Windows versions; given kernel-level nature, conduct regression testing in staging before production deployment.
- Consultation6.0 h
- Implementation4.0 h
- Testing8.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,144.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2016-3221 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2016-3221 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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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.
- 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
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