Download iOS 6.1.3 (10B329) for iPhone 4 (GSM)

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 iPhone3,1
iOS Version 6.1.3
Release Date 1970-01-01
Update Date 2013-03-13
Sha1sum
f8c53328656f2708e1d2bcb793f12ae46dd4eb23
Sha256sum
6bcce44ca93851cecfc87e932f6272ff84bf73b9bab0c2f0c8aeb30eedfda6fa
md5sum
845a42c0139cdad6d373bf3414b25786
Size 0.87 GB
FileName
iPhone3,1_6.1.3_10B329_Restore.ipsw
Status

Download IPSW (0.87GB) Check device info
Release Notes

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

iOS 6.1.3

This update contains improvements and other bug fixes including:

For information on the security content of this update, please visit this website:

http://support.apple.com/kb/HT1222