In addition to the many features highlighted in iOS 12 yesterday, it appears that Apple may also be doubling-down on Lightning port security in iOS 12. A report last month highlighted a new “USB Restricted Mode” that showed up in iOS 11.4 after briefly appearing in earlier betas, designed to lock down data communications through the Lightning port if an iPhone hadn’t been unlocked in at least seven days.
Now, according to a new report by Motherboard, iOS 12 is going to reduce that time frame to a mere hour, a significant change that will basically neuter the recent “GrayKey” and “Cellebrite” boxes that are being used by law enforcement to hack into locked iPhones. The feature basically means that users will need to unlock their iPhone with the passcode when connecting to a USB accessory if the iPhone has been locked for more than an hour. As Ryan Duff, a security researcher who has studied iPhone and is Director of Cyber Solutions at Point3 Security, told Motherboard, “That pretty much kills GrayKey and Cellebrite” since the feature blocks any type of data connection through the iPhone’s Lightning port, and “You can’t exploit the device if you can’t communicate with it.”
The release notes for the first iOS 12 developer beta, released yesterday, indicate that this feature applies to using “iPod Accessory Protocol” (iAP) USB accessories via the Lightning port, “such as CarPlay, assistive devices, charging accessories, or storage carts” as well as any connection to a Mac or PC, adding that “If you don’t unlock your device, it won’t communicate with the accessory or computer, and it won’t charge.” This last point is interesting, as it appears that this feature will block charging from certain third-party accessories, although it’s unclear where the distinction is, since Apple notes that users won’t need to unlock the device “to charge using an Apple USB power adapter.” iOS 12 also adds a new “USB Accessories” setting under Face ID/Touch ID & Passcode that allows users to disable the feature, intended primarily for those users who normally use USB assistive devices to enter their passcode.