Apple has released iOS 11.4.1, which improves stability and the Find My AirPods feature. It also introduces USB Restricted Mode, a feature designed to prevent a third party from attempting unauthorized access to a locked iPhone via the Lightning port and USB. When the phone has been locked for a full hour, all USB access is disabled. However, security researchers at ElcomSoft have discovered that attaching any USB device to the iPhone will reset this 1-hour clock, providing a an easy workaround for any third party that comes into possession of the phone within an hour of its last use. A new toggle in the settings lets users disable this security feature.
Source: Phone Scoop – Latest News