CVE-2024-20666Public exploit

Encrypted-data access via attacker-supplied SYSTEM hive

Published Jan 9, 2024 · Updated May 3, 2025

BitLocker bypass in Windows Recovery Environment allows physically proximate attackers to access encrypted data on affected Windows systems. Winload honors an attacker-controlled systemdatadevice entry and loads an external SYSTEM hive whose Setup!CmdLine launches a SYSTEM shell in WinRE. Physical access and low privileges are required; the shell exposes BitLocker keys already present in memory and grants access to protected volumes.

CVSS severity6.6
Medium
EPSS probability3.10%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

BitLocker bypass in Windows Recovery Environment allows physically proximate attackers to access encrypted data on affected Windows systems. Winload honors an attacker-controlled systemdatadevice entry and loads an external SYSTEM hive whose Setup!CmdLine launches a SYSTEM shell in WinRE. Physical access and low privileges are required; the shell exposes BitLocker keys already present in memory and grants access to protected volumes.

The record

CVE
CVE-2024-20666
Published
Jan 9, 2024
Updated
May 3, 2025
Vendor
Microsoft
Product
Windows 10 Version 1507
Classifications
CWE-693, T1005
Attack vector
physical
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 9, 2024CVE publishedPublication date reported by the CVE source.
  2. May 3, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=10.0.10240.0 <10.0.10240.20402

What conditions does exploitation require?

Attack vectorphysical
Required privilegesauthenticated

What is affected?

Microsoft · Windows 10 Version 1507version=10.0.10240.0 <10.0.10240.20402
Microsoft · Windows Server 2019version=10.0.17763.0 <10.0.17763.5329
Microsoft · Windows Server 2016 (Server Core installation)version=10.0.14393.0 <10.0.14393.6614
Microsoft · Windows 11 version 21H2version=10.0.0 <10.0.22000.2713
Microsoft · Windows 10 Version 21H2version=10.0.19043.0 <10.0.19044.3930
Microsoft · Windows Server 2022, 23H2 Edition (Server Core installation)version=10.0.25398.0 <10.0.25398.643
Microsoft · Windows Server 2016version=10.0.14393.0 <10.0.14393.6614
Microsoft · Windows 11 Version 22H3version=10.0.22631.0 <10.0.22631.3007
Microsoft · Windows 10 Version 22H2version=10.0.19045.0 <10.0.19045.3930
Microsoft · Windows Server 2019 (Server Core installation)version=10.0.17763.0 <10.0.17763.5329
Microsoft · Windows 11 Version 23H2version=10.0.22631.0 <10.0.22631.3007
Microsoft · Windows 11, version 22H2version=10.0.22621.0 <10.0.22621.3007
Microsoft · Windows 10 Version 1607version=10.0.14393.0 <10.0.14393.6614
Microsoft · Windows Server 2022version=10.0.20348.0 <10.0.20348.2227
Microsoft · Windows 10 Version 1809version=10.0.0 <10.0.17763.5329; version=10.0.17763.0 <10.0.17763.5329

Published CVSS scores

6.6Microsoft CorporationCVSS:3.1/AV:P/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-693Protection Mechanism Failure
T1005Data from Local System

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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