If you receive a strange text from someone that looks like Arabic script and then your iPhone crashes; you have been a victim of a newly discovered flaw in iOS Unicode. Reports indicate that when the specific block of text is sent in a text message to an iPhone, it locks up the message app and triggers iPhone restarts, lockouts from Messages, and Springboard crashes.
Folks on Reddit set about trying to figure out what causes the text in the message to wreak such havoc on the iPhone and have narrowed it down to how iOS handles Unicode. The short snippet of text you see in the image here is apparently part of a much longer string of text that can’t be fully rendered in Notifications on the iPhone.
When the long block of Unicode is received on the iPhone and is viewed on the lock screen or as a drop-down notification, the device uses up resources trying to render the full message which eventually causes Springboard to crash.
Interestingly if the line of Unicode is received as part of a normal messages chat session, it doesn’t cause issues. That suggests that part of the reason the iPhone crashes when the code is viewed on the lock screen or as a drop down is because of an issue with iOS Notifications. If you are hit with the Unicode and your device locks up, the fix is to send out a picture from photos or send yourself a message using Share Sheets. Those feats will reportedly stop the process and give users back functionality.