Ferdinand gave away the free kick which allowed Steven Gerrard to put the home side in front, but Javier Hernandez spared the centre-back's blushes with a headed leveller ten minutes from time.
"We're happy with the point," Ferdinand told Sky Sports News. "I thought parts of the second half we controlled and played some good football.
"If we could have made the right decisions in the final third then perhaps we could have created a couple more openings."
United remain top of the Premier League, one point above neighbours Manchester City.