Apple has patched a major flaw in its Group FaceTime feature that allowed callers to eavesdrop on people they called even if they never picked up. The bug, CVE-2019-6223, allowed anyone with iOS to FaceTime other iOS users and listen in on their private conversations without the user on other end rejecting or accepting the call. The update comes along with a slew of other fixes in its release of iOS 12.1.4.1. Apple also said it would pay a reward to the teen that identified the bug.
Source: https://threatpost.com/apple-fixes-pesky-facetime-bug-in-ios-12-1-4-update/141621/