CVE-2021-1652
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 CSC Service 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 confidenceCVE-2021-1652 is a local elevation of privilege vulnerability in the Windows Client-Side Caching (CSC) service. The vulnerability allows a low-privileged attacker to gain higher system-level privileges on the affected Windows system. The CSC service is used for offline file caching in Windows environments.
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
- 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 versionRun 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' to obtain the exact Windows version and build numberAffected if The version matches any of the affected versions: Windows 7 (all), 8.1 (all), 10 (all versions including 1607, 1803, 1809, 1909, 2004, 20h2), Rt 8.1, Server 2008 (all including R2), Server 2012 (all including R2), Server 2016 (all including 20h2, 1909, 2004), Server 2019 (all)
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Verify CSC service presenceOpen Services console (services.msc) or run 'sc query cscservice' to check if the Client-Side Caching service is present on the systemAffected if The CSC service exists on the system - the vulnerability affects this specific service component
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Confirm security patch statusRun 'wmic qfe list' or check Windows Update history for installed security updates related to January 2021 or CVE-2021-1652Affected if No security update addressing CVE-2021-1652 (January 2021 Patch Tuesday) is installed, or the system lacks recent security patches
A system is affected if it runs any supported Windows version from the affected list AND lacks the CVE-2021-1652 security update, with the CSC service available as the target component for privilege escalation.
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 appropriate Microsoft security update for CVE-2021-1652 to all affected Windows systems. As this is a local privilege escalation vulnerability, ensure systems are not exposed to untrusted users and follow least-privilege principles.
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 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 $5,408.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-1652 — 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-2021-1652 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