Security News > 2023 > May > New BrutePrint Attack Lets Attackers Unlock Smartphones with Fingerprint Brute-Force

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 framework.

The flaws, Cancel-After-Match-Fail and Match-After-Lock, leverage logical defects in the authentication framework, which arises due to insufficient protection of fingerprint data on the Serial Peripheral Interface of fingerprint sensors.

The result is a "Hardware approach to do man-in-the-middle attacks for fingerprint image hijacking," researchers Yu Chen and Yiling He said in a research paper.

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. The first of the two vulnerabilities that render this attack possible is CAMF, which allows for increasing the fault tolerance capabilities of the system by invalidating the checksum of the fingerprint data, thereby giving an attacker unlimited tries.

MAL, on the other hand, exploits a side-channel to infer matches of the fingerprint images on the target devices, even when it enters a lockout mode following too many repeated login attempts.

News URL

https://thehackernews.com/2023/05/new-bruteprint-attack-lets-attackers.html