TTLock Android application before v9.8.260718 and associated smart-lock firmware contain a hardcoded static AES key vulnerability that allows an attacker within Bluetooth range to decrypt the per-pairing session key transmitted during BLE pairing. Attackers can observe the pairing exchange, recover the persistent session key using the embedded defaultKey, and forge authenticated BLE requests to unlock the device, add fingerprints or access codes, and perform administrative actions without authentication or user interaction.