Ireb 4.0.x 4.1 Rc2.zip 1 Access

When modifying early iOS devices, users rely on custom IPSW firmware packages (created via tools like Sn0wBreeze or PwnageTool) to jailbreak or preserve baseband versions for carrier unlocks. However, stock iTunes software checks the structural integrity of incoming firmware before flashing.

It does this by putting the device into a special "pwned DFU" state and uploading three necessary 'pwned' files to your iDevice using a component called iTunnel. In this state, iTunes cannot upload a standard patch that would normally block the installation of custom firmware. iREB 4.0.x 4.1 RC2.zip 1