CVE-2021-1709
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 an elevation of privilege vulnerability in the Windows Win32k kernel-mode driver (win32k.sys). The vulnerability allows a local attacker to escalate privileges from a low-privileged user context to SYSTEM level by exploiting a flaw in how Win32k handles certain GUI operations.
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= 20h2= 1607= 1803= 1809= 1909= 2004all versionsall versionsall versionsall versions= r2all versions= r2all versions= 20h2= 1909= 2004all 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
- High
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:H/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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Confirm Windows version is in the affected product listRun 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' to identify the installed Windows version and edition.Affected if The installed version is Windows 10 (any build), Windows 7, Windows 8.1, Windows RT 8.1, Windows Server 2008/2012/2016/2019 (any build)
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Check if security update KB4598229 is installedRun 'wmic qfe list' or open Control Panel > Programs > View installed updates' and search for KB4598229, or run 'Get-HotFix -Id KB4598229' in PowerShell.Affected if The update KB4598229 (or a later cumulative update containing this fix) is NOT installed.
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Check win32k.sys file versionLocate win32k.sys in C:\Windows\System32\drivers\ and view the File Version property, or run 'powershell (Get-Item C:\Windows\System32\drivers\win32k.sys).VersionInfo'.Affected if The file version is lower than the version that includes the KB4598229 fix (compare against Microsoft's security bulletin version information).
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Verify if user account control or additional hardening is in placeReview local user accounts and group memberships to confirm whether untrusted low-privileged users have interactive logon rights to the system.Affected if Untrusted low-privileged users have the ability to logon interactively to the affected system (since exploitation requires a local user context).
The system is likely affected if it runs an affected Windows version AND does not have KB4598229 installed AND allows low-privileged local users to log on interactively.
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 the Microsoft security update KB4598229 (or subsequent cumulative update) which addresses this vulnerability. Prioritize patching domain controllers and privileged workstation assets.
- Consultation2.0 h
- Implementation4.0 h
- Testing6.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,808.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-1709 — 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-2021-1709 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