"It's rather disturbing and allows for a crazy invasion of privacy without the other person pressing 'OK' and starting the call," he said.
In effect, it turned a person's phone into a live mic and camera without their knowing it.
This was first reported by the website 9 to 5 Mac. Apple announced that the company is working on a software update that will fix this problem, which is expected to be released by the end of the week. In the meantime, the company disabled group FaceTime calls.
When Dr. Rob D'Ovidio, a cybersecurity expert from Drexel, first heard about the glitch, his reaction was "No, not again." That's because with software constantly changing, updates issued regularly, it's hard for people behind the scenes to keep up.
"We have to recognize that people aren't perfect and it's people that are testing the systems," he added, "so something is going to get by."
D'Ovidio said sites like 9 to 5 Mac play a "vital role" in keeping the public informed and safe when it comes to tech.
There are no known bugs with one-on-one FaceTime calls. To play it safe, users can turn off FaceTime by going to "Settings," tapping "FaceTime," and then tapping the button on the top of the screen that turns it off.