iPhone, iPad and Mac return to being put in crisis by a string of particular characters in sindhi. Just receive a properly formatted message to make the devices completely "catatonic" – to the point that not even the physical volume or power buttons work.
It is not possible to return to the Home with a swipe from the bottom or by pressing the physical button, in older iPhones. According to the reports, it is only a matter of wait a few minutes for the device to come out of the impasse by itself; alternatively, it is possible to force a reset by simultaneously pressing the power button and the button to increase the volume. To prevent crashes it is suggested to disable the display of notifications – but it has some obvious rather important contraindications.
The first version of the attack also included the Italian flag, but further evidence has shown that Sindhi characters are enough, which is the language of the region of Pakistan called Sindh. The practical consequences of this "flaw" are far more serious than those of the mail client, but given how easy it is to conduct it and since the victim has no way of defending himself (unless he resorted to jailbreak and replace those specific characters with other text , they found out on Reddit) is becoming viral in its own way.
Not all versions of iOS are vulnerable, but the latest publicly available yes; the most recent beta no. In any case, for the moment Apple has not spoken publicly, but it is reasonable to expect the arrival of a fix within a few days.
This curious type of bug is somewhat recurrent for Apple devices. The last one dates back to 2018, and that time the "cause" was an Indian character. In 2015 the string "Effective Power" had become famous.