Apple has rolled out a minor update to the iOS operating system for iPhone, iPod touch, and iPad. The update is specifically designed to patch a vulnerability that allowed hacked PDF files to inject code onto an iOS device.
In other words, the update patches the security hole that @comex used to create the JailbreakMe 3.0 tool that allowed almost anyone to jailbreak a device just by visiting a web site in the mobile Safari web browser.
The latest update is iOS 4.3.4 for most devices. The version number for Verizon iPhone users is iOS 4.2.9.
If you’re not a jailbreaker, you’ll probably want to install the update since it will protect you from any malicious software trying to use the same technique. If you do have a jailbroken device, you may want to avoid updating since you’ll lose your jailbreak.
Odds are that you’ll be able to re-jaibreak your phone using redsn0w or sn0wbreeze, but those tools take a little more work than JailbreakMe. But for now prominent iPhone hacker MuscleNerd advises staying away from iOS 4.3.4 and backing up your iOS 4.3.4 SHSH blobs. The easiest way to do that is to use a tool such as iFaith or TinyUmbrella.
Download links are here.
http://www.iphoneleaks.net/2011/07/download-ios-4-3-4-ios4-3-4/