Apple fixes iOS bug that causes crash when receiving Taiwanese flag emoji

With the release of iOS 11.4.1, Apple has fixed a bug that in certain circumstances caused chat apps to crash, such as iMessage or WhatsApp. The crash occurred when typing the word Taiwan or receiving an emoji of the Taiwanese flag.

Apple patched the dos vulnerability CVE-20180-4290 in the latest version of iOS and thanked security researcher Patrick Wardle for reporting it. Wardle, who specializes in Apple software, has now published a blog post about his findings. In it, he writes that he was approached by a Taiwanese friend who had to deal with the bug. Wardle subsequently managed to reproduce the phenomenon consistently. He found out that the bug was related to a null pointer dereference when iOS removed certain emoji from received messages.

Wardle explains that before the removal, iOS checks that the device’s region is set to China. The solution to the specific problem of his girlfriend living in America turned out to be the repeated switching of the region between the US and China. He refers to previous discussions, including on the MacRumors forum, which would indicate that the Taiwanese flag is not available for Chinese iOS users. Wardle writes, “Has Apple modified iOS code to please the Chinese government? Sure! But if that code is buggy, users suffer.”

China does not recognize Taiwan, also known as the Republic of China, as a sovereign state. Under the so-called One China policy, the country sees Taiwan as part of China.