The iPhone's New 'USB Restricted Mode' Can Be Bypassed by Cheap Accessories

How to use USB Restricted Mode on your iPhone or iPad

On the day of its official release, technology security gurus are raising a red flag over Apple's new security feature, USB Restricted Mode.

However, security firm Elcomsoft noted in a blog post that you can reset this one-hour timer by plugging in a USB accessory - like this Lightning to USB 3 Camera Adapter that Apple itself makes - before the feature kicks in, so as to buy time to transport the phone back to a secure facility for investigation.

USB Restricted Mode was most likely designed in response to hackers like Grayshift developing tools and methods to break into iOS devices.

The restricted mode was put into a beta version of the latest update and has made it through to the final release, making it virtually impossible for law enforcement (or others) to gain access to someone's phone before the USB port is shut down. This new mode, which is buried under your passcode settings, adds additional security to your iOS device by preventing USB accessories to connect with your iPhone or iPad if the device has been locked for more than one hour.

If you don't first unlock your password-protected iOS device - or you haven't unlocked and connected it to a USB accessory within the past hour - your iOS device won't communicate with the accessory or computer, and in some cases, it might not charge.

Now you'll want to make sure that the USB Accessories toggle is turned off in order to enable USB Restricted Mode.

A GrayKey box for unlocking Apple mobile devices. According to Elcomsoft, even untrusted accessories can do this, and the company believes that it should be able to keep an iPhone unlocked even with $2 iPhone cables from online Chinese stores.

Enter your device's passcode.

In the middle of writing this report, an additional update - iOS 11.4.1 - has been pushed out by Apple, though it's not clear whether this explicitly fixes the battery drain issue or not. Users on iOS 11.3.1 or lower are advised to stay where they are. 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.

"We don't know if this behavior is here to stay, or if Apple will change it in near future".

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