Bugs are usually bad news for phone owners, ranging from mild annoyances to downright dangerous. Sometimes, the patch released to fix the problem messes things up even more. An iOS bug discovered Monday might not fit into any of these categories, as it is difficult to activate. Nevertheless, it will still freeze your iPhone.
Italian website AmiciApple broke the story on April 24, based on a YouTube video demonstrating the bug. The bug itself is fairly innocuous, but it's something you should know about nonetheless. As far is we can tell, it works on at least iOS 10.2 and above, even right up to iOS 10.3.2 beta 4, for iPad, iPhone, and iPod touch.
To freeze your iPhone, swipe up from the bottom to activate the Control Center. Using three fingers, tap three different buttons in Control Center (the original video tapped the Calculator, Night Shift, and Airdrop buttons simultaneously). Once you release your fingers, your iPhone should be frozen.
No amount of tapping will unfreeze it, and you'll have to wait until your iPhone automatically restarts for it to start working normally again.
If the iPhone is not automatically restarting itself after about 10 seconds, to fix the issue, simply hard reset the device by holding the Sleep/Wake and Home buttons simultaneously for 10 seconds, and your iPhone will be good as new.
If you want to avoid this bug altogether, enabling "Zoom" toggle in Settings -> General -> Accessibility -> Zoom prevents the freeze-up from happening. This is because the Zoom feature relies on a three-finger double-tap gesture, which apparently supersedes the bug since iOS is now paying attention to three-finger taps.
As of this article, there has been no word from Apple on any fixes for the bug coming to iOS. In the meantime, don't tap on the Control Center with three fingers — unless of course, you want to try it out (or if you enabled "Zoom").