iOS 13.3.1 (build 17D5050a) is an official Apple over-the-air update for the iPhone 7 (GSM), released on 2020-01-22T18:07:33Z. The update package is 165.6 MB. This is a delta (partial) update that requires 13.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 92e6edd3251a01d3313b72131bd389f738d722da.zip.