Yep. Except that they're very difficult to harness. They're not like you see in Star Trek. Wormholes actually exist all around us but they are only on the sub-atomic level, they only open for less than a nanosecond, and if something passed through it then it would only travel less than the distance of an atom.
Professor Kip Thorne (one of my favorite theoretical physicists) theorised that we could take these one end of these pre-existing wormholes and drag it to a far away star. Then is we passed through it we would instantaneously travel through it. Well, kindof instantaneously. He theorised that if we travelled through it then it would be a blink of an eye for us, but in reality time would have passed by the amount of light years we traveled.
The major flaw as Thorne explained it is that in order to open this wormhole about 1 metre wide and keep it open for long enough for something to pass through, it would take a large amount of dark energy. About the size of Jupiter worth of dark energy. Or to put it another way. An amount of dark energy 1,300 times the size of earth.