Moments ago, Apple has released iOS 4.3.4 for iPhone, iPad and iPod touch. Previously, we had reported that Apple may release iOS 4.3.4 firmware to patch the PDF based exploit which JailbreakMe uses to jailbreak the iPad 2, and other supported iOS devices.
While the iOS 4.3.4 release notes don't specifically point out that the company has patched JailbreakMe 3.0 PDF exploit, they only say that iOS 4.3.4 comes with security fixes. It is true actually, as the exploit used by JailbreakMe existed in mobile Safari, and it could be used by any hacker with devious intentions to gain root access on your device.
iOS 4.3.4 supports iPhone 3GS, iPhone 4, iPad 1, iPad 2, iPod touch 3G, 4G. Actually, Apple never really planned on releasing iOS 4.3.4. iOS 5 betas were pushed out and before JailbreakMe 3.0 leak, we were pretty sure that from iOS 4.3.3, Apple would straight away roll out iOS 5 for end users. However, with the discovery of such a major vulnerability, the company had no choice but to release iOS 4.3.4.
You can either connect your iOS 5 to the computer and upgrade from iTunes, or you can manually download the iOS 4.3.4 ipsws from the official download links provided by Apple, given down below and then proceed to do a manual restore using iTunes. Simply download the iOS 4.3.4 ipsw, then connect your device to the computer, launch iTunes and if you're on Windows, Press and hold the Shift key and click on Restore to select the ipsw you have downloaded. Mac users need to press and hold the alt key.