Apple has confirmed reports that a bug in iOS and Messages is causing phones to crash after receiving certain texts. The bug occurs when an iPhone receives a particular string of non-Latin alphabet characters -- i.e. Arabic or Mandarin characters. If the iPhone is currently on the lock screen when the message is received, the phone will shut down and reboot.
The bug was first spotted by reddit users and has been confirmed to affect any iOS phones. The particular text needed to shut down someone's phone is unusual enough that it's extremely unlikely someone would send them by mistake. The Guardian provides a more in-depth explanation: "When the text message is displayed by a banner alert or notification on the lockscreen, 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 video below provides an example of this bug.
Apple has confirmed that they are aware of the problem and will be rolling out a software update to address the issue.