This is a huge miss on the part of Apple to allow this level of flaw/vulnerability into the wild.  If rumors are true, this issue was also covered up for a bit while a patch was under construction.  Please take the time to disable FaceTime on your iOS and MacOS devices immediately until a patch can be distributed by Apple.

https://nakedsecurity.sophos.com/2019/01/29/apple-facetime-eavesdropping-bug/

https://www.schneier.com/blog/archives/2019/01/iphone_facetime.html

https://www.infosecurity-magazine.com/news/group-facetime-disabled-while/