Secure Boot bypass via truncated policy memory
Published Jan 11, 2022 · Updated Jan 2, 2025
Secure Boot bypass in Microsoft Windows Boot Manager allows local administrators to execute unsigned code during system startup. The truncatememory BCD setting removes the serialized Secure Boot policy from the memory map before boot applications read it, enabling bootdebug, testsigning, and nointegritychecks. Exploitation requires local administrative or physical access and can establish pre-operating-system persistence while disabling platform defenses.
Summary
What happened
Secure Boot bypass in Microsoft Windows Boot Manager allows local administrators to execute unsigned code during system startup. The truncatememory BCD setting removes the serialized Secure Boot policy from the memory map before boot applications read it, enabling bootdebug, testsigning, and nointegritychecks. Exploitation requires local administrative or physical access and can establish pre-operating-system persistence while disabling platform defenses.
The record
- CVE
- CVE-2022-21894
- Published
- Jan 11, 2022
- Updated
- Jan 2, 2025
- Vendor
- Microsoft
- Product
- Windows 10 Version 1507
- Classifications
- CWE-863, T1542.003
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Jan 11, 2022CVE publishedPublication date reported by the CVE source.
- Jan 2, 2025Record 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.
- Affected versionversion=10.0.10240.0 <10.0.10240.19177
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Public exploit references
- Baton Drop proof of conceptfunctional · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Reported exploitation
- BlackLotus exploitation of Baton Dropreported exploitation
Technologies
Your stack
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Your stack
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