At the end of last month there was an update for all iPhone, iPad and iPod Touch users, with which the Apple i device could be brought to iOS 11.4. Just one day later, the iOS 11.4.1 beta for developers and early adopters came out. A new function in it is the restricted USB mode, which only charges the same when connecting the smartphone or tablet via Lightning to a USB socket and prevents data exchange. Such a restricted USB mode on the iPhone under iOS 11.4 or 11.4.1 protects against attacks, for example the GrayKey box, or at modified charging stations while traveling.
Apple iPhone with iOS 11.4.1 - Restricted USB mode
As of iOS 11.4.1, data transfer is generally prevented when an iPhone or iPad is connected to a USB port (via the Lightning socket on the device). When connecting to a Mac, PC or other USB source, the user must then determine whether the data exchange should be enabled or whether it should remain blocked.
So if you just want to charge your smartphone or tablet or its battery, you don't have to do anything else for your safety after the iOS update. You only have to be active if you want to use it with iTunes on the Mac or PC or with other services. After activating the data exchange, the restricted USB mode automatically restarts after a period of inactivity.
Responding to GrayKey Box and Other Security Concerns
Not just the GrayKey box (Professional analysis), which reads security codes from the iPhone by trying too hard in a comparatively short time, is a problem for the security of Apple smartphones with a Lightning connector. Other alleged charging stations at the train station or airport, in a hotel or in Airbnb accommodation could also be equipped with spy and hack functions. Without wanting to paint the devil on the wall, the PC / Mac in the holiday apartment could also be equipped in such a way that it pulls data from the connected smartphone unnoticed when it is clamped to the USB port to charge the battery.
Use in the Apfelot home
I switched on the option because the iTunes sync, backups and the photo library run on my WiFi or iCloud anyway. So I only need the Lightning socket for charging. If you do the same, then activate the feature or leave it activated when it becomes the standard on iOS 11.4.1. Spy software on your own computer will then no longer have access to the iPhone connected via USB. I think Apple has created a good security update with the limited USB mode function and is responding appropriately to GrayKey and Co.
Jens has been running the blog since 2012. He appears as Sir Apfelot for his readers and helps them with problems of a technical nature. In his free time he drives electric unicycles, takes photos (preferably with his iPhone, of course), climbs around in the Hessian mountains or hikes with the family. His articles deal with Apple products, news from the world of drones or solutions for current bugs.
Did you like the article and did the instructions on the blog help you? Then I would be happy if you the blog via a Steady Membership would support.
In the Sir Apfelot Blog you will find advice, instructions and reviews on Apple products such as the iPhone, iPad, Apple Watch, AirPods, iMac, Mac Pro, Mac Mini and Mac Studio.
2 comments on “Restricted USB mode on iPhone running iOS 11.4.1”
"When connecting to a Mac, PC or other USB source, the user must then specify whether data exchange should be enabled or remain blocked."
And then this cannot be manipulated!?!?
Well, it's an additional backup. But it can apparently also be manipulated, because the makers of the GrayKey-Box advertise that they can crack iPhones with the latest iOS. So it seems to be cracked already ...