The visitors, 61 places higher than their hosts, failed to produce their usually slick attacking football and could not break down the Conference side, with the best chances coming in the second half for both sides.
Huddersfield winger Anthony Pilkington, searching for his eighth goal in seven games, forced Cambridge stopper Danny Naisbitt into a low save before fizzing a long-range drive past the post.
United's Danny Wright had the best chance of the game when he got on the end of Wayne Gray's low cross only to turn the ball straight at Town keeper Ian Bennett.
Benik Afobe, on loan from Arsenal, showed glimpses of his undoubted potential, forcing Naisbitt into a full-stretch save with time running out.
The Us could have nicked it in time added on but Robbie Willmott shot straight at Bennett and referee Paul Tierney waved away a penalty appeal.