Medium · published May 27, 2026
SpSoft AppLock (com.sp.protector.free) 7.9.40 for Android allows a local attacker with physical access to bypass fingerprint or PIN authentication. Although the app integrates Android's biometric mechanisms, the lock is implemented with a custom overlay that fails to consistently enforce authentication. By navigating cascading interface flows - insecure navigation through exposed routes facilitates app control evasion {I.N.T.E.R.F.A.C.E] via advertisement or browser intents - an attacker can exit the lock interface without re-authentication and access protected apps (e.g., Chrome). This results in information disclosure and privilege escalation.