iOS 11.2.1 (build 15C153) is an official Apple over-the-air update for the iPhone 8 (Global), released on 2017-12-13T18:10:47Z. The update package is 65.88 MB. This is a delta (partial) update that requires 11.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: b4b033a08d105f4dba73c8d5a37ea962d07d904f.zip.