MacRumors reports that Apple has today released iOS 4.3.4, which is solely designed to plug the security hole that was discovered and used for the JailbreakMe.com jailbreak that finally enabled people to jailbreak their iPad 2s, among other devices. Unfortunately, it was found that the vulnerability could be used to launch malicious code on iOS devices. According to the note that comes with the update, it “fixes security vulnerability associated with viewing malicious PDF files.”
The update works for the iPhone 4/3GS, third and fourth generation iPod touches, and all iPad versions. The CDMA iPhone 4 gets its own specific update, iOS 4.2.9. All that you have to do to get the update is connect your iOS device to iTunes. Don’t forget, though, if your device is jailbroken, if you install the update, you’ll lose your jailbreak, so don’t update if you don’t want that to happen. Jailbreakers should stay tuned to the Forum to find out what to do next.
Source: Apple Releases iOS 4.3.4 to Address Latest Jailbreaking Vulnerability - Mac Rumors