As a cultural phenomenon, emojis seem to be the natural evolution from more “old school” style emoticons. No longer just a small set of pictograms, emojis now compromise several hundred tiny digital images. Users pepper their text messages with them and fill up social media posts with emojis. The iPhone, like many other smartphones, includes its own built-in library of standard emojis. However, a recently uncovered flaw in the way some versions of iOS render a particular emoji can cause instability and inaccessibility for some iPads and iPhones.
What units does this bug affect? If your iPhone still runs iOS 10.0 or 10.1, someone could potentially trigger this issue on your device. iOS 10.2 and forward are immune to this exploit. So how does it work? It revolves around creating a rainbow flag emoji — one which is not yet officially supported.
The problem occurs in the method of combining a waving white flag with a rainbow in order to create a rainbow flag emoji. This is normally done using a special sequence: a waving white flag, a variation selector character (VS16), and a rainbow. VS16 tells iOS to combine the emoji on either side of it into a single emoji. The disruptive message, however, actually contains the white flag, VS16 (which you don’t see), a zero, and a rainbow emoji. However, iOS cannot combine the white flag with a zero. The result is that the device receiving the text instantly locks up — even if you never open the text. Fortunately, the problem resolves itself after a few short minutes. A prankster sending the same message over and over, however, could cause significant disruption. Deleting the message will stop the problem from recurring.
Packaging these characters into a contacts file and then sharing them to a user via the iCloud Drive feature causes the same type of problem. These bugs are separate from the issue in which large contacts files were causing the Messages app to fail completely. While disruptive, they do no lasting damage to your phone. Even so, it’s best to ensure you can’t fall victim to this exploit.
If you are still running iOS 10.1, now would be a good time to upgrade. Avoiding this emoji issue isn’t the only reason, though. There have been several very important security patches issued in updates following 10.1. It might be time to think about grabbing your device and pressing the upgrade button today.