iOS 7 will plug a security hole that makes your handset vulnerable to hacking through the use of a fake charger.
The fake charger looks like the standard one that comes with the iPhone, but the hardware is modified. It has some differences that make it possible to install a trojan on the iPhone. From there, a person can hack the iPhone and really mess with the victim,
Here’s a portion of the original report that describes the charger:
In a demonstration at the hacking conference, they plugged an iPhone into a custom-built charger they equipped with a tiny Linux computer that was programmed to attack iOS devices. They said it cost about $45 to buy and a week to design.
The warning shows the user that they are plugging into a computer rather than an ordinary charger. Oh, remember that little notification we saw earlier today? That explains it.