Instead of getting all involved in a way to repair the Ethernet cable itself, you can just jury-rig a solution using tie wraps. Just like duct tape, tie wraps have a million different uses. We especially like them for managing cables. In a bind, they will service you well.
Laxap over at Instructables has posted a handy way of repairing Ethernet cables using tie wraps. All you'll need is two tie wraps, a razor knife, and a pair of pliers. That's something that you probably already have around the house. We like this Instructable since Laxap has really broken down the steps needed to repair the plug. You shape the end of a tie wrap into a tab that will lock into an Ethernet port. It's pretty straightforward. Once you bend it into shape, you'll use the second tie wrap to fasten it tightly to the cable and voila! Problem solved!