It may not make everyone laugh but it's the little fun that quickly went around the web. How could it have been discovered? mystery and gum ball. Apple admits a concern in any case.
With a very specific message received, it is possible to crash the Messages application and even cause the iPhone to restart. The Messages application is not a priori the only one to point the finger, while versions prior to iOS 8 are not necessarily affected.
It was necessary in any case to have a sacred imagination to think of a series of Arabic characters and symbols to cause a crash:
Apple is content to evoke a particular series of unicode characters in an iMessage which is the cause of a problem, and adds that a software update will be offered to remedy this. In the meantime, a workaround is available. Thanks Siri.
Its purpose is to be able to reopen the Messages application. Ask Siri to read the unread messages and then respond to the malicious message. Enough to open Messages again. In the application, it will be necessary to delete said message.
Note that the famous bug does not necessarily work for everyone. This adds to its mystery.