Due to an insecure design, the Lepin EP-KP001 flash drive through KP001_V19 is vulnerable to an authentication bypass attack that enables an attacker to gain access to the stored encrypted data. Normally, the encrypted disk partition with this data is unlocked by entering the correct passcode (6 to 14 digits) via the keypad and pressing the Unlock button. This authentication is performed by an unknown microcontroller. By replacing this microcontroller on a target device with one from an attacker-controlled Lepin EP-KP001 whose passcode is known, it is possible to successfully unlock the target device and read the stored data in cleartext.