A newly discovered iOS bug can cause the Messages app to crash when a certain string of characters is received.
If the iPhone is locked when the message is received, it reboots without notice. According to reports, it only crashes Messages and reboots an iPhone if the message was sent from another Apple handset.
This seems to happen because of the way iOS renders Arabic text. When a message is displayed via banner alert or notification on the lock screen, the system attempts to abbreviate the text with an ellipsis. If the ellipsis is placed in the middle of a set of non-Latin script characters, including Arabic, Marathi and Chinese, it causes the system to crash and the phone to reboot.
The bug seems to require a very specific string of text to be sent. The Guardian went through many variations of the string before successfully replicating the crash. Naturally, people on social networks are sharing the exact string needed.
If you’re worried about falling victim to the prank/bug/attack, you can disable notification banners.
After receiving the offending text, you may be unable to open the Messages app. Receiving another message seems to rectify this issue. If you can’t wait for someone to send you a text, you can text yourself using Siri or send a photo to the contact via the Photos app.