The iPhone's New 'USB Restricted Mode' Can Be Bypassed by Cheap Accessories
Jul 11 2018
Computer security forensics firm ElcomSoft has found a $39 device - one Applesells on its on website - that runs contrary to Apple's instructions, fooling the restricted mode and giving access to anyone using the device.
That time allowance may be convenient, but the flip side is someone might be able to access data on the iPhone within the hour.
USB Restricted Mode is created to protect against devices such as GrayKey, a hardware device that enables an attacker to extract data from an iOS device they don't have legitimate access to. Once an iPhone has been locked, a countdown begins before USB Restricted Mode activates.
The accompanying explanation gives no indication of its real objective: "Unlock iPhone to allow USB accessories to connect when it has been more than hour since your iPhone was locked", it says underneath a sliding bar.
For more information on the USB Restricted Mode and how to toggle it on or off, Apple has a guide here.
According to researchers at ElcomSoft, if a USB accessory is plugged into the phone before the one-hour time limit has elapsed, it will reset the counter.
It has been seen that the lock doesn't get affected with Apple Lightning to 3.5mm jack adapter, though the one-hour countdown was reset through the official Lightning to USB 3 Camera Adapter. As the company says though, it is likely an oversight from Apple which will perhaps be fixed in a future point release of iOS 11.4 or when iOS 12 releases later this year. Once complete, you will be notified and will have the ability to set the device up as an entirely new device or restore it from a compatible iTunes or iCloud backup. Apparently, during a forensic security presentation, Grayshift said that they can now only request passcodes once every ten minutes, since the iOS 11.4 update. However, Apple had not released the details on its security page at the time of this posting, but expect them to appear sometime soon.
At first we thought we would have to wait until iOS 12 this fall to see this feature, but here it is. Another user having similar issues claims that the iPhone was updated to iOS 11.4, charged to 100%, rebooted and left in standby for four hours.