Apple has released iOS 18.3.1, bringing bug fixes and important security improvements to iPhone, including patching a security flaw that’s actively been exploited.
According to Apple, iOS 18.3.1 fixes an authorization issue where a physical attack may disable USB Restricted Mode on a locked device, with the iPhone noting that it is aware of a report that this issue may have been exploited in a sophisticated attack against specific targeted individuals.
Apple’s USB Restricted Mode, introduced in iOS 11.4.1, prevents data access via the charging port if the device has not been unlocked within the last hour. This feature is designed to protect against unauthorized access from hacking tools like GrayKey, which exploit USB connections to bypass passcodes. When enabled, after an hour of inactivity, the charging port can only be used for charging, not data transfer, unless the device is unlocked with a passcode, Face ID, or Touch ID.
Apple advises all users to upgrade to iOS 18.3.1, and the respective iPadOS 18.3.1 update, immediately.