When mobile operating systems get political…
A feature to help the Chinese government censor talk of Taiwan on iPhones in the country can been found to crash the devices.
According to security researcher Patrick Wardle, a flaw in the code means that the iPhone sees a Taiwan emoji to be an invalid input.
Wardle said on his Objective-See blog that a Taiwanese friend of his said that every time she typed the word Taiwan or worse, received a message with a Taiwanese flag (:flag-tw:) it would crash the application on her (fully patched) iOS device.
This meant that anyone could crash her phone if they sent messages not only containing the word Taiwan but also any mention of the country. Wardle then investigated the issue.
Wardle discovered that the cause of the bug was an intentional censorship feature built into every iPhone. The bug was in a function related to emoji processing returning a NULL pointer, this caused the app to crash.
Wardle also found that the OS would remove the Taiwanese flag emoji from received messages if a user had set their region as China. Instead, it would show a missing symbol image. When the region was set to China, the Taiwan flag would also disappear from the emoji list.
“Does Apple really add code to iOS to appease the Chinese government? Of course!” Wardle said. “And when that code is buggy, their users suffer.”
Once the bug was discovered the fix for this was to set the region to China and back again to US.
Wardle informed Apple of the bug and helped it fix this (Apple noted this in a security update on Monday). The bug has now been fixed in iOS 11.4.1