A few days back Apple released a security patch for their iOS devices to fix a major hole in their security that would allow a hacker to steal your username and password for your email. For most this username and password would be the same as they use to access their network. Details on the security issue are below with links to Apples site.
What is concerning however is that Apple have given no indication of what if anything they plan to do about patching the older devices. Early version iPhones/iPads and even Apple TV are left wide open from what I understand to this issue.
Apple TV 6.0.2 Apple TV 2nd generation and later
iOS 7.0.6 iPhone 4 and later, iPod touch (5th generation), iPad 2 and later
iOS 6.1.6 iPhone 3GS, iPod touch (4th generation)