In case you missed it, Apple just released iOS 5.1.1 for iPhone, iPad, and iPod Touch. The software update includes your typical “improvements and bug fixes” as well as security improvements. Remember the iOS 5.1 vulnerability that allows malicious websites to display fake URLs on your device? iOS 5.1.1 resolves that.
Compatibility of the iOS 5.1.1 update is limited to all Apple devices capable of running iOS 5. That includes iPhone 3GS, iPhone 4, iPhone 4S, third- and fourth-generation iPod Touch, iPad, iPad 2 and the new iPad. It resolves three major security issues present in iOS 5.1. One of them is the Safari vulnerability which allows malicious websites to spoof the actual URL on the location bar. The other two are WebKit related problems wherein visiting malicious websites either led to a cross-site scripting attack or unexpected termination of running apps. Additionally, the latest software update does the following:
• Improve reliability of HDR option for taking phones via the Lock Screen shortcut
• Improve reliability of Safari bookmarks and Reading List syncing
• Fix bugs on AirPlay video playback
• Fix “Unable to Purchase” issue that displays even after a successful purchase
• Fix bugs that kept the new iPad from switching between 2G and 3G networks
The easiest way to update your device is over-the-air. All you have to do is go to Settings > General > Software Update. We already told you not to upgrade to iOS 5.1 given its many security glitches, but we recommend this new one. The Safari vulnerability was the most alarming security problem of iOS 5.1 and the iOS 5.1.1 software update clears your mind of that.
via Apple Support