dbcve.org
Windows 10Operating system · Microsoft

CVE-2021-1685

HIGH · 7.3 CVSS v3.1 Published 2021-01-12
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
73/100
Remediation priority · Elevated

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
Windows AppX Deployment Extensions 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 confidence

This is a local elevation of privilege vulnerability in Windows AppX Deployment Extensions. An authenticated attacker could exploit this to gain higher privileges on the affected system by manipulating AppX deployment operations.

MitigationApply the relevant Microsoft security update for CVE-2021-1685 via Windows Update or manual patch deployment to remediate the vulnerability.

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
Windows 10Operating system
Affected:all versions= 20h2= 1607= 1803= 1809= 1909= 2004
Windows Server 2016Operating system
Affected:all versions= 20h2= 1909= 2004
Windows Server 2019Operating system
Affected:all versions

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
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/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 checks

Work through these to decide whether this CVE applies to you.

  1. Check Windows version and build number
    Open Command Prompt and run: winver OR run 'systeminfo' and look at OS Name and OS Version. For build number, run 'winver' or check Settings > System > About
    Affected if The installed version matches Windows 10 20h2, 1607, 1803, 1809, 1909, 2004 or Windows Server 2016/2019/20h2/1909/2004 (any version)
  2. Confirm AppX Deployment service is present
    Open Services.msc and locate 'AppX Deployment Service (AppXSVC)' or run: sc query AppXSVC
    Affected if The AppX Deployment Service exists on the system (standard component in affected Windows versions)
  3. Check if security update KB5000802 is installed
    Open Control Panel > Programs and Features > View installed updates, or run: wmic qfe get HotFixID,InstalledOn | findstr /i KB5000802
    Affected if The KB5000802 update is NOT installed - system is unpatched for this CVE

User is affected if running a supported Windows 10/Server version AND the AppX Deployment Service is present AND KB5000802 is not installed.

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 the relevant Microsoft security update for CVE-2021-1685 via Windows Update or manual patch deployment to remediate the vulnerability.

Fix this in Windows 10 Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,190
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,904.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-1685 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2021-1685 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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