dbcve.org
Hevc Video ExtensionsPlugin / extension · Microsoft

CVE-2021-1644

HIGH · 7.8 CVSS v3.1 Published 2021-01-12
Fix available
A fix is available. Upgrade to 1.0.33242.0 or later.
See remediation →
81/100
Remediation priority · High
No privileges

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
HEVC Video Extensions Remote Code Execution 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

A remote code execution vulnerability exists in Windows HEVC Video Extensions that allows an attacker to execute arbitrary code via specially crafted video files. The high CVSS score of 7.8 indicates low attack complexity with no authentication or user interaction required.

MitigationApply available Microsoft security updates for HEVC Video Extensions or disable the extension if not required until patching is feasible.

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
Hevc Video ExtensionsPlugin / extension
Affected:< 1.0.33242.0

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
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/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 checks

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

  1. Confirm Hevc Video Extensions is installed
    Open PowerShell and run: Get-AppxPackage *Hevc* or check Windows Features for 'HEVC Video Extensions'
    Affected if The package or feature is present on the system
  2. Retrieve the installed version number
    Run: Get-AppxPackage *Hevc* | Select-Object Name, Version in PowerShell, or right-click the app in Settings > Apps & Features and view version info
    Affected if A version number is returned showing the installed build
  3. Compare version against the vulnerable range
    Compare your installed version to 1.0.33242.0 - any version lower than 1.0.33242.0 is affected
    Affected if Installed version is less than 1.0.33242.0
  4. Check if HEVC codecs are actively used
    Review installed video codecs or media players that may invoke HEVC handling - check Windows Media Player settings or third-party codec packs
    Affected if HEVC decoding is enabled and the system handles HEVC video files

If Microsoft Hevc Video Extensions is installed with a version lower than 1.0.33242.0 and the system processes HEVC video files, the environment is vulnerable to CVE-2021-1644.

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
Upgrade available Upgrade to 1.0.33242.0 or later
Fixed in 1.0.33242.0
Interim mitigation

Apply available Microsoft security updates for HEVC Video Extensions or disable the extension if not required until patching is feasible.

Fix this in Hevc Video Extensions Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.

Scan for this in your stack

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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-2021-1644 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