Download iPadOS 11.2.1 (15C153) for iPad Air (WiFi)

You will have to note that you can only restore signed IPSW firmware files using iTunes or 3utools.

❌ This IPSW firmware is not being Signed by Apple

Firmware Identifier iPad4,1
iPadOS Version 11.2.1
Release Date 2017-12-13
Update Date 2024-06-03
Sha1sum
98008b7a930d13fac33bb97a7fdb62c308c61408
Sha256sum
1a8e0a11f7052f4f7379efb976d1b2139a8bedf33d3b9a3f25fb19d430c3b551
md5sum
fed9a02455ecbba7c3702399a7d65222
Size 2.34 GB
FileName
iPad_64bit_11.2.1_15C153_Restore.ipsw
Status

Download IPSW (2.34GB) Check device info
Release Notes

It should be noted that these are the official release notes for the from Apple

iOS 11.2.1 fixes bugs including an issue that could disable remote access to shared users of the Home app.

For information on the security content of Apple software updates, please visit this website:

https://support.apple.com/kb/HT201222