I thought after so many complaints that Apple would actually do something about this issue, but nearly 2 years later, NO. I made the mistake of updating my iPhone 5 a few days ago, and have just spent the last couple of hours fixing Apple's indifference.
I have an Apple phone and and Apple computer, so surely there should be no problem.
(I have an iPhone 5 and the issue has arisen twice after updating iOS later than 7.0.
SOLUTION: for me is an app called KEXT UTILITY to fix AppleUSBEthernetHost.Kext file.
Google those items to find the right file, or use Time Machine to find the working file from your old system on your Mac (before you updated your phone).
Good luck to every disgruntled Apple user.