CVE-2021-40452

Code execution after user interaction

Published Dec 15, 2021 · Updated Nov 18, 2024

Remote code execution in Microsoft HEVC Video Extensions before 2.0.23022.0 allows attackers to execute code after user interaction. Microsoft identifies the affected codec package but has not published the malformed input, decoder locus, or incorrect operation that triggers execution. A user must invoke the vulnerable codec operation; successful exploitation runs code in that user's security context.

CVSS severity7.8
High
EPSS probability2.51%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Remote code execution in Microsoft HEVC Video Extensions before 2.0.23022.0 allows attackers to execute code after user interaction. Microsoft identifies the affected codec package but has not published the malformed input, decoder locus, or incorrect operation that triggers execution. A user must invoke the vulnerable codec operation; successful exploitation runs code in that user's security context.

The record

CVE
CVE-2021-40452
Published
Dec 15, 2021
Updated
Nov 18, 2024
Vendor
Microsoft
Product
HEVC Video Extensions
Classifications
T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 15, 2021CVE publishedPublication date reported by the CVE source.
  2. Nov 18, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=N/A

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Microsoft · HEVC Video Extensionsversion=N/A

Published CVSS scores

7.8Microsoft CorporationCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
6.8Microsoft CorporationCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1204.002Malicious File

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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