Everyone with a Samsung Galaxy S10: If you’re using the biometric fingerprint to unlock your phone, you have no security until Samsung releases an update to address an issue that lets anyone unlock your device using their thumb.
As reported in The Sun earlier this week, a British couple discovered that when using a screen protector on their Galaxy S10 smartphone, the fingerprint scanner would accept any print instead of only the print of its owner.
A woman learned that she could use her left thumbprint to unlock her device, despite only ever registering the print from her right thumb. And then it was found that her husband could open the phone by using either of his thumbs.
In this situation, the phone was paired with a certain gel screen protector that was purchased on eBay for £2.70. It’s unclear whether the issue involves all types of screen protectors, but Samsung has warned anyone who uses their Galaxy handset with a screen protector to disable the fingerprint scanner and switch to another option for unlocking the device, at least until a fix is released.
The Galaxy S10 has unique hardware for scanning fingers. It uses ultrasound to map the 3D ridges of a fingerprint and it has been previously reported that some screen protectors are incompatible with this scanner because they created a small air gap that hindered scanning. Fortunately, Samsung says it’s going to fix the problem with an upcoming software patch.
What’s also unclear is whether any other Samsung models are affected, such as the Galaxy Note 10, which also features an ultrasonic fingerprint scanner. To turn off your fingerprint reader: Go to the Settings app > Lock Screen > Screen lock type, then enter your unlock code for access to the option that will let you switch off the Fingerprints unlock setting.