Persistent unsigned-code execution via trusted upgrade-step value
Published Dec 11, 2023 · Updated May 27, 2025
Secure Boot bypass in U-Boot on Google Android SoC devices allows physically proximate attackers to execute persistent unsigned code. The AVB verification path trusts the writable upgrade_step environment value and treats value 3 as both permission to ignore verification errors and a successful verification result. The demonstrated chain requires physical eMMC fault injection to obtain a U-Boot shell; it can then boot modified images while Android reports the device as locked and secure.
Summary
What happened
Secure Boot bypass in U-Boot on Google Android SoC devices allows physically proximate attackers to execute persistent unsigned code. The AVB verification path trusts the writable upgrade_step environment value and treats value 3 as both permission to ignore verification errors and a successful verification result. The demonstrated chain requires physical eMMC fault injection to obtain a U-Boot shell; it can then boot modified images while Android reports the device as locked and secure.
The record
- CVE
- CVE-2023-48425
- Published
- Dec 11, 2023
- Updated
- May 27, 2025
- Vendor
- Product
- Android
- Classifications
- CWE-20, T1553.006, T1542.003
- Attack vector
- physical
- Privileges
- unauthenticated
Timeline
How it unfolded
- Dec 11, 2023CVE publishedPublication date reported by the CVE source.
- May 27, 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?
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- Affected versionversion=Android SoC
What conditions does exploitation require?
What is affected?
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.
Weakness, pattern, technique
Public exploit references
- Chromecast with Google TV 1080P secure-boot bypass chainfunctional · demonstrated
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Technologies
Your stack
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Your stack
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