iOS 4.3.4 addresses the PDF exploit in mobile Safari used by JailbreakMe and few more security fixes. JailbreakMe 3.0 doesn’t work for iOS 4.3.4. Blocking this untethered jailbreak seems to be the Apple’s only goal with this release. Apple hadn’t planned for this release but with such dangerous threat (that could lead users to have malware loaded onto their devices) in the wild, they had to do it. Viewing a maliciously crafted PDF file may lead to an unexpected application termination or arbitrary code execution. Download iOS 4.3.4 from below.
JailbreakMe 3.0 is a jailbreaking solution that allows devices to be hacked without a computer, just by pointing Mobile Safari to a JailbreakMe’s website. A pre-released version of this tool was leaked over the weekend, providing an untethered jailbreak for the iPad 2 for the first time before the final official release last week. So Apple released iOS 4.3.4 to address this issue.
Caution: If you’ve jailbroken or are planning to jailbreak your iPad 2 using JailbreakMe, stay away from this update and install PDF Patcher 2 from Cydia instead, which provides the same benefits as this update, and it won’t break your jailbreak. Just launch Cydia, search for “PDF Patcher 2” and install it.
In order to install the iOS update do this:
Connect your phone to your computer.
Select your device from the sidebar.
Click on “Check for Updates”.
Select “Download and Install” when prompted.
After the download, your device should begin to update.
After you’ve downloaded the firmware, you can install the software manually by launching iTunes, locating your device on the sidebar and pressing “Restore” while holding the Shift key on Windows and Alt on the Mac. Apple published a support document, confirming that PDF exploit exposed by JailbreakMe 3.0 has been fixed.