iOS 7.1.2 (build 11D257) is an official Apple over-the-air update for the iPhone 4 (GSM / 2012), released on 2014-06-30T18:00:03Z. The update package is 152.36 MB. This is a delta (partial) update that requires 7.0.3 already installed. This update is currently signed by Apple, so it can be applied from Settings › General › Software Update.

Payload file: 19baf070a17201559619a7392611ac70f4736104.zip.