Apple has released iOS 11.4.1 bringing USB Restricted Mode, first introduced in the current iOS 12 beta, and some bug fixes. USB Restricted Mode is designed to make your iPhone and iPad immune to certain hacking techniques used by law enforcement or other potentially malicious entities to gain access to an iOS device.
Some iPhone access methods use a USB connection, downloading data from your iPhone (or iPad) through the Lightning connector to crack the passcode. iOS 12 prevents this by disabling data access to the Lightning port if it’s been more than an hour since your iOS device was last unlocked.
USB Restricted Mode is enabled by default when you update to iOS 11.4.1 (or iOS 12), but it can be toggled off if necessary. In reality, it should be enabled but, at the moment in the iOS 12 beta, these USB restrictions appear to shut down access to a wired CarPlay interface after an hour, so that’s one exception where people might want to turn this setting on to disable the restrictions on the USB port. Technically, I would descirbe this as a bug Apple need to sort asit is preferable to minimise the situations where a user would need to diable the feature.
Changing USB Restricted Mode Settings
- Open the Settings app.
- Choose Touch ID & Passcode or Face ID & Passcode, depending on the device.
- Enter your passcode to access the settings.
- Scroll down to the bottom of the app where it says “USB Accessories.”
- Leave it toggled off to disable access to your iOS device if you want it to refuse USB connections if it’s been more than an hour since the iPhone or iPad was unlocked.
- Toggle it on if you want USB accessories to be able to connect even if it’s been more than an hour since the iPhone or iPad was unlocked.
iOS 11.4.1 is available on all eligible devices over-the-air in the Settings app. To access the update, go to Settings –> General –> Software Update.