Apple came with an iOS update this Monday and have urged its all iOS users to update their devices immediately. The iOS 5.1.1 patch fixes 3 serious security issues found in the existing devices, mostly browser based bugs.
The updated iOS version 5.1.1 will work on iPhone 3GS, iPhon 4, iPhone 4S, iPod Touch (3rd generation and later), as well as the iPad, iPad 2, and new iPad.
However, jailbroken devices can also update to iOS 5.1.1 excluding newer devices like iPhone 4S, the iPad 2, and the iPad which came after the iPad 2.
One address bar spoofing bug and 2 webkit browser based bugs are addressed in this security update.