CVE-2021-1732
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 · uneditedWindows Win32k Elevation of Privilege Vulnerability
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 confidenceThis is a privilege escalation vulnerability in the Windows Win32k subsystem (win32k.sys kernel driver). It allows a low-privileged local attacker to elevate to SYSTEM/Administrator privileges.
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 versionsall versionsall versionsall versionsall versionsall versionsall versionsall 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
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/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 checksWork through these to decide whether this CVE applies to you.
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Identify Windows version and build numberOpen Command Prompt and run 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' to see the exact Windows version and build numberAffected if The version is Windows 10 1803, 1809, 1909, 2004, or 20h2; or Windows Server 1909, 2004, or 2019
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Confirm win32k.sys is presentCheck that the system uses the Win32k graphics subsystem by verifying the presence of %SystemRoot%\System32\win32k.sysAffected if The win32k.sys file exists on the system (standard on all affected Windows versions)
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Verify the vulnerability is unpatchedRun 'systeminfo' and check the 'Hotfix(s)' field for KBxxxxxxx patches, or check Windows Update history for February 2021 security updates. The specific patch is the February 2021 security update for CVE-2021-1732.Affected if The system is one of the affected versions listed AND lacks the February 2021 security update for this CVE
The system is affected if it runs Windows 10 1803/1809/1909/2004/20h2 or Windows Server 1909/2004/2019 AND has not received the February 2021 security update that addresses CVE-2021-1732.
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.
dbcve · scopedApply the Microsoft security update KBxxxxxxx released in February 2021 (or later cumulative update) to patch the win32k.sys vulnerability.
- Navigate to the Microsoft Security Response Center (MSRC) portal at portal.msrc.microsoft.com and search for CVE-2021-1732
- Locate the specific security update (KB) for your Windows version from the February 2021 Patch Tuesday
- Apply the security update via Windows Update, or download the specific KB from the Microsoft Update Catalog
- Restart the system to ensure the update is fully applied
- Verify the patch was installed successfully by checking the installed updates
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation2.0 h
- Testing6.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,160.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-1732 — 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-2021-1732 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
- No spam, self-promotion, credentials, or personal data