iOS 8.1.2 (build 12B440) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2014-12-09T17:49:04Z. The update package is 1.14 GB. This is a delta (partial) update that requires 7.1.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 491a4a2a88df7ae098e9f32f1c16b6ad551cdd4d.zip.