CVE-2021-34466Public exploit

Physical authentication bypass via infrared image replay

Published Jul 16, 2021 · Updated Aug 10, 2026

Authentication bypass in Microsoft Windows 10 Version 1809 through Version 21H1 allows physically proximate attackers to unlock a device. Windows Hello Face accepts replayed infrared frames from a custom USB camera that mimics a trusted biometric sensor instead of authenticating live capture. Exploitation requires face enrollment, full physical device access, a victim infrared image, and custom hardware; it grants device access without a valid face.

CVSS severity5.7
Medium
EPSS probability0.81%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Microsoft Windows 10 Version 1809 through Version 21H1 allows physically proximate attackers to unlock a device. Windows Hello Face accepts replayed infrared frames from a custom USB camera that mimics a trusted biometric sensor instead of authenticating live capture. Exploitation requires face enrollment, full physical device access, a victim infrared image, and custom hardware; it grants device access without a valid face.

The record

CVE
CVE-2021-34466
Published
Jul 16, 2021
Updated
Aug 10, 2026
Vendor
Microsoft
Product
Windows 10 Version 21H1
Classifications
CWE-290, T1200
Attack vector
physical
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 16, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 10, 2026Record 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=10.0.0 <10.0.19043.1110

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

Microsoft · Windows 10 Version 21H1version=10.0.0 <10.0.19043.1110
Microsoft · Windows 10 Version 1909version=10.0.0 <10.0.18363.1679
Microsoft · Windows 10 Version 20H2version=10.0.0 <10.0.19042.1110
Microsoft · Windows 10 Version 2004version=10.0.0 <10.0.19041.1110
Microsoft · Windows 10 Version 1809version=10.0.0 <10.0.17763.2061; version=10.0.17763.0 <10.0.17763.2061

Published CVSS scores

3.6NIST NVDAV:L/AC:L/Au:N/C:P/I:P/A:N
6.1NIST NVDCVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
5.7Microsoft CorporationCVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

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)
Vectorphysical
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-290Authentication Bypass by Spoofing
T1200Hardware Additions

Public exploit references

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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