The release of iREB for iOS 4.0.x and 4.1 was significant because iOS 4.1 was a major update that introduced Game Center and HDR photography, making it a desirable update for iPhone 3G, 3GS, and iPhone 4 users. However, Apple had patched previous jailbreak exploits.
While iREB was a household name for iPhone enthusiasts in 2010 and 2011, the tool is now considered obsolete. iREB 4.0.x 4.1 RC2.zip 1
The primary purpose of iREB is to patch the Apple Mobile Device (iBoot/iBSS) protocol to allow a "Pwned" state. In simpler terms, it tricks iTunes into accepting a custom, modified firmware file that Apple would normally reject. The release of iREB for iOS 4
During the iOS 4.0/4.1 era, users attempting to jailbreak their devices (using tools like Sn0wbreeze or PwnageTool) often encountered iTunes Error 1600, 1601, 1602, 1603, or 1604. These errors indicated that the device was refusing the custom restore. iREB was the fix for this, pushing the device into a state where it would accept the custom payload. The primary purpose of iREB is to patch
