Apple has disabled a group-chat function in FaceTime after users said a software bug could let callers activate another person�s microphone remotely.

With the bug, a FaceTime user calling another iPhone, iPad or Mac computer could hear audio � even if the receiver did not accept the call. The bug is triggered when callers add themselves to the same call to launch a group chat. That makes FaceTime think the receiver had accepted the chat.

The bug, demonstrated through videos online , comes as an embarrassment for a company that is trying to distinguish itself by stressing its commitment to users� privacy.

�This is a big hit to their brand,� said Dave Kennedy, CEO of Ohio-based security firm TrustedSec. �There�s been a long period of time people could have used that to eavesdrop. These things definitely should be caught prior to ever being released.�

There is no longer a danger from this particular bug as Apple disabled group chats, while regular, one-on-one FaceTime remains available.

NBC News and The Wall Street Journal reported Tuesday that the family of a 14-year-old high school student in Tucson, Arizona, tried to inform Apple about the bug more than a week before it became widely known to the public. The boy, Grant Thompson, said he discovered it by accident while calling friends to play the game �Fortnite.�

It�s hard to know if anyone exploited the bug maliciously, said Erka Koivunen, chief information security officer for Finnish company F-Secure. He said it would have been hard to use the bug to spy on someone, as the phone would ring first � and it�s easy to identify who called.

Apple said Tuesday that a fix will come in a software update later this week. Apple declined to say when it learned about the problem. The company also wouldn�t say if it has logs that could show if anyone took advantage of the bug before it became publicly known this week.

Kennedy commended Apple�s quick response this week following reports of the bug by tech blogs. He predicted the reputational dent could soon be forgotten if it doesn�t become part of a pattern.

�All bugs are obvious in retrospect,� said Eva Galperin, director of cybersecurity at the Electronic Frontier Foundation. �The truth is bugs are subtle, code is complicated and sometimes things get through.�

Galperin said Apple should develop a better process for fielding reports about potential security flaws. She said the 14-year-old�s discovery of the problem �just tells us a lot about reporting security bugs depends on knowing the right person.�

Apple had introduced the 32-person video conferencing feature in October for iPhones, iPads and Macs. Regular FaceTime calls aren�t affected unless the caller turns it into a group chat.

Word of the bug came as Apple reported that profit for the last three months of 2018 dipped slightly to $20 billion while revenue fell 5 percent from the prior year to $84 billion. Earlier this month, Apple said that demand for iPhones was waning and that its earnings for the final quarter of 2018 would be below its own forecasts � a rare downgrade from the company.

(AP)