Well, sort of, but not really. You could add "sinua" or "teitä" at the end there, but it's not necessary since you do assume that it is either of those when there is no pronoun. Then again, it could also just as well be e.g. "kuinka voin auttaa häntä?" if that suits the context. But of course addressing "you" is much more common.
But yes, I think "How can I help" should also be accepted as a valid translation of the Finnish sentence.