Apple this evening has stopped signing three previous versions of iOS following the release of iOS 11.2.5 last week. Specifically, the company has stopped signing iOS 11.2, iOS 11.2.1, and iOS 11.2.2 for all devices…
Apple regularly stops signing older iOS firmware versions in an effort to ensure that the majority of users are on the most recent releases. When the company closes signing for a specific version, it means users are no longer able to downgrade to that version.
For instance, prior to today, a user running iOS 11.2.5 would have been able to downgrade to either 11.2, iOS 11.2.1, or iOS 11.2.2 through iTunes. That downgrading window is now closed, however.
Jailbreak users, or hopeful jailbreak users, are often the most affected by Apple’s decisions to stop signing older iOS versions. Last month for instance, a potential jailbreak was teased for iOS 11.2.1, though never released to the public. Downgrading to that iOS version for a jailbreak, should it ever be released, is now impossible.
iOS 11.2.5 was released to the public last week, bringing Siri enhancements, official support for the HomePod, and a host of bug fixes and performance improvements. Coinciding with the public release of iOS 11.2.5, Apple started beta testing iOS 11.3, which includes new Animoji, iMessages in the Cloud, AirPlay 2, and much more.
Source: 9to5mac