On 29 January 2013, Apple released an update (6.1) for its popular iOS operating system, used by mobile devices including the iPhone, iPad and iPod touch.

The update brings some new functionality, but importantly, it also addresses a number of security concerns.

These vulnerabilities could be exploited by someone with malicious intent. You are advised to update your devices as soon as possible. Updates are generally available for the iPhone 3GS and later, iPod Touch (4th generation) and later, iPad 2 and later.

More detail about the security aspect of the update is available on Apple’s website.
https://support.apple.com/kb/HT5642

Advertising Identifier Reset Button
Also of note in this update is Apple’s introduction of a button to reset the device’s Advertising Identifier. It means you’ll be able to better control the ability of advertisers to track your device and target their ads accordingly. You can find this under Settings > General > About > Advertising

 

How to update your iOS device:

http://support.apple.com/kb/HT4623

Apple provides the following information about this update:
https://support.apple.com/kb/HT5642