Google Project Zero security researcher Natalie Silvanovich has disclosed an issue with iMessage that could lead to the Apple phones needing to be wiped and restored to function correctly.
Silvanovich said in a blog post that a malformed message, containing a text key that was not a string, could cause an exception to be thrown. When this property was used by another method assuming it was a string but never checking it actually was a string, it caused another exception to occur.
“On a Mac, this causes agent to crash and respawn, but on an iPhone, this code is in Springboard,” Silvanovich said.
Springboard is the application that handles the iOS home screen.
“Receiving this message will case Springboard to crash and respawn repeatedly, causing the UI not to be displayed and the phone to stop responding to input,” the security researcher added.
“This condition survives a hard reset, and causes the phone to be unusable as soon as it is unlocked.”
Silvanovich said there are three ways to unbrick a device, but they all involved wiping or restoring the device.