An important bug on the FaceTime group chat has been recently uncovered, first reported by 9to5. The bug allows people to hear the audio and see video of Facetime users before they pick up a call and without notifying them.
This affects anyone with an iPhone and iPad that runs iOS 12.1 or later, and computers running macOS Mojave with the Group FaceTime feature.
According to Apple, the bug will only be fixed later in the week, once a new software update is available.
Tl;DR A glitch in FaceTime allows people to hear audio and see the video of FaceTime users without notifying them. To disable this, go into your settings on your phone, and turn FaceTime off. On the Mac, go into the FaceTime app to disable it.
The steps to activating the bug are relatively simple, and there are no indications on your device that indicate you are being recorded. According to 9to5, recording begins before you pick up, and continues until you've picked up or declined the call
Of course, your phone will ring as it normally would, so it is not a 100% covert way of spying, but it still poses a very serious privacy concern. Anyone with a Mac or an iPhone could call you, and record you without your knowledge.
It has been reported that it is even possible to activate the receiver's camera, which means that the bug could expose your video to the person calling you without your permission. In this case, you would be able to hear the caller's audio, but you would have no indication to the fact that the caller can see you.
It seems that the only way to disable the bug for now is to shut down Facetime altogether.
To do so on your iPhone or iPad, go into your settings, scroll down until you see FaceTime menu, and click on it. Disable the app by swiping the green toggle, so that it goes white instead of green.
To disable FaceTime on your Mac, open Facetime, click on the "FaceTime" tab that opens on the top left of the screen, and select "turn FaceTime off."