A bug was discovered in Apple’s FaceTime services yesterday evening and news of its existence has rocketed around the world. The bug allows members of a group FaceTime call to eavesdrop on what’s happening with other users — before those users have answered or even if they’ve declined the call. The bug is so easy to replicate for users of iOS 12.1 that Apple has taken group FaceTime offline for now while they work on a fix.
How the bug worked is quite simple.
— Benji Mobb™ (@BmManski) January 28, 2019
The Apple devices in question need to be running iOS 12.1 or newer. One user initiates a video call with another iPhone user and, while the call is still dialling, that user swipes up and selects Add Person. Popping the phone number of the person making the initial call into that section automatically begins the group FaceTime session — while pulling in the audio from the second user (who at this point has not answered the call).
There were also a few methods discovered to get Apple’s devices to transmit video (by just pressing the Power button to dismiss the call, for instance) without one party being aware that it was taking place. At this point it’s no wonder that Apple has opted to shut down group FaceTime altogether while it works on a fix. The update shouldn’t take much more than a week to implement.