Samsung Rushing to Fix Bug Allowing Anyone’s Fingertip to Unlock Galaxy S10

Samsung is rushing to fix a bug in the Galaxy S10’s fingerprint scanner that allows the phone to be unlocked with anyone’s finger, providing a third-party screen protector is being used.

The bug was first reported by The Sun, who was tipped off by a reader. After a reader bought a cheap “gel cover” to protect her Galaxy S10’s screen, she quickly learned that she could use any of her fingers to unlock it, despite only registering her right thumb. Her husband was also able to unlock her phone with an unregistered fingerprint.

“We called Samsung because we thought there was a fault with the phone,” the person told The Sun. “The man in customer services took control of the phone remotely and went into all the settings and finally admitted it looked like a security breach.”

Samsung told Reuters on Thursday that it will address the new problem with a software patch. The company said: “Samsung Electronics is aware of the case of the S10’s malfunctioning fingerprint recognition and will soon issue a software patch.”

Some third-party screen protectors can confuse the ultrasonic fingerprint sensor, the South Korean phone maker said in a notice on its customer support app. KaKaobank, a Korean online bank, has advised owners to turn off S10 fingerprint recognition until the patch arrives.

It’s currently unclear exactly how the S10’s ultrasonic sensor is being fooled by the screen protector, but it likely has something to do with how the scanner itself works. Unlike a conventional optical fingerprint scanner, which optically matches a fingerprint, the S10’s sensor uses ultrasonic waves to detect a fingerprint in full 3D, including the unique depth of a print’s ridges. Such a method was assumed to be more secure, with nothing less than a 3D-printed fingerprint being required to fool it previously.

If you have a Galaxy S10 and are using a third-party case, we’d suggest you opt for face unlock feature, at least until your handset gets patched.