• Journal of the Korea Institute of Information Security & Cryptology
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• v.34 no.4
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• pp.651-666
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• 2024

Android devices employ lock screens with various authentication methods to protect user data. However, even with the lock screen active, the device can be accessed via the Android Debug Bridge(ADB), a powerful development tool that controls devices connected through USB. In this paper, we explore methods to bypass the lock screen security mechanism by leveraging the characteristics of ADB. To achieve this, we analyze ADB commands to categorize those that can severely impact the Android system and propose LockPickFuzzer, a fuzzing test tool that automatically explores ways to combine these commands to disable lock screen security. To demonstrate LockPickFuzzer's ability to detect security vulnerabilities using ADB, we conducted experiments on the Galaxy S23 and Pixel 8, both running Android 14. The results revealed two ADB command combinations that could either steal authentication information or bypass the lock screen. We submitted a report on these discovered vulnerabilities to the Samsung security team and received official acknowledgment (SVE-2023-1344) from Samsung Electronics for one ADB command combination that can be reproduced on user devices. LockPickFuzzer is a practical tool that operates automatically without user intervention and is expected to contribute to the effective detection of security vulnerabilities caused by ADB command combinations on Android devices.