Researchers have discovered an inexpensive attack technique that could be leveraged to brute-force fingerprints on smartphones to bypass user authentication and seize control of the devices.
The approach, dubbed BrutePrint, bypasses limits put in place to counter failed biometric authentication attempts by weaponizing two zero-day vulnerabilities in the smartphone fingerprint authentication (SFA) framework.
The flaws, Cancel-After-Match-Fail (CAMF) and Match-After-Lock (MAL), leverage logical defects in the authentication framework, which arises due to insufficient protection of fingerprint data on the Serial Peripheral Interface (SPI) of fingerprint sensors.
The result is a “hardware approach to do man-in-the-middle (MitM) attacks for fingerprint image hijacking,” researchers Yu Chen and Yiling He said in a research paper. “BrutePrint acts as a middleman between fingerprint sensor and TEE [Trusted Execution Environment].”
The goal, at its core, is to be able to perform an unlimited number of fingerprint image submissions until there is a match. It, however, presupposes that a threat actor is already in possession of the target device in question.
Additionally, it requires the adversary to be in possession of a fingerprint database and a setup comprising a microcontroller board and an auto-clicker that can hijack data sent by a fingerprint sensor to pull off the attack for as low as $15.
images from Hacker News