Key recovery via attacker-controlled IV reuse
Published Aug 5, 2021 · Updated Aug 3, 2024
IV reuse in Samsung Mobile Devices before SMR AUG-2021 Release 1 allows local users to decrypt custom Keymaster keyblobs. The Keymaster trusted application accepts an undocumented caller-supplied IV, allowing AES-GCM nonce reuse when deterministic key derivation produces the same encryption key. Exploitation requires a privileged process able to bypass the Keymaster HAL and submit arbitrary trusted-application parameters; successful reuse recovers protected key material.
Summary
What happened
IV reuse in Samsung Mobile Devices before SMR AUG-2021 Release 1 allows local users to decrypt custom Keymaster keyblobs. The Keymaster trusted application accepts an undocumented caller-supplied IV, allowing AES-GCM nonce reuse when deterministic key derivation produces the same encryption key. Exploitation requires a privileged process able to bypass the Keymaster HAL and submit arbitrary trusted-application parameters; successful reuse recovers protected key material.
The record
- CVE
- CVE-2021-25444
- Published
- Aug 5, 2021
- Updated
- Aug 3, 2024
- Vendor
- Samsung Electronics Co., Ltd.
- Product
- Samsung Mobile Devices
- Classifications
- CWE-20, CWE-330, T1552.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 5, 2021CVE publishedPublication date reported by the CVE source.
- Aug 3, 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.
- Affected versionversion=O(8.1), P(9.0), Q(10.0) <SMR AUG-2021 Release 1
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
- Keybuster IV Reuse Attack PoCproof of concept · demonstrated
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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