Select your specific device model inside the application interface.
Look for the tool on community-vetted sites like The Apple Wiki or archived versions of jailbreak forums.
for Windows XP or 7 and ensure you have an older version of iTunes (11.x or 12.0) installed, as newer versions of iTunes often lack the drivers necessary to communicate with these legacy tools. specific mirror for a particular build, or instructions for a different iOS version ireb 40x 41 421 rc3zip link
Many users seeking this specific, older version of iREB are likely involved in or restoring legacy Apple devices to early firmware versions. In 2026, finding reliable, original software tools for older iOS versions can be difficult, as many original hosting sites have long been inactive [2].
Once DFU mode is detected, iREB will automatically execute the exploit. The software will display a success message stating: "Your device is now in a Pwned DFU state." The device screen should remain completely black. Step 3: Run the iTunes Restore Select your specific device model inside the application
Since the original developer website ( ih8sn0w.com ) no longer hosts these legacy direct download links, modern enthusiasts and retro-tech collectors must rely on trusted archival platforms.
The specific versions you're researching (4.0.x, 4.1, and 4.2.1 RC3) are key milestones in iREB's history, each corresponding to support for different versions of Apple's iOS at the time. specific mirror for a particular build, or instructions
When you attempt to upload a custom IPSW (iOS firmware file) to an Apple device, iTunes checks the hardware environment. If it detects a custom bootloader or modified software packages, it immediately triggers a 16xx series error and halts the installation.
This is where iREB came to the rescue. The tool works on a deep, low-level principle: it uploads three specially crafted "pwned" files (iBSS.MODEL.RELEASE.dfu, WTF.MODEL.RELEASE.dfu, etc.) to the iOS device's memory. This effectively unlocks the device's bootrom, creating a "Pwned DFU" (Device Firmware Upgrade) state. In this state, iTunes's security checks are bypassed, and it can now restore the custom firmware without any errors, allowing for a jailbreak or an iOS downgrade.
The "4.0.x-4.1-4.2.1 RC3" version is specifically tailored for that era of iOS. It provides the most stable method for pushing custom firmware onto: iPhone 2G/3G/3GS iPod Touch 1G/2G/3G Key Features of iREB RC3