It was Nemeth who gave Boro the lead after 10 minutes, but Villa fought back with goals from Gabriel Agbonlahor and Liam Ridgewell, to go in at half time 2-1 up.
Maccarone equalised in the second half to earn a point for Boro in an overall entertaining game.
An injury sustained to Tony McMahon could rule him out of Saturday's Premiership opener against Liverpool.
Boro team:
Jones, McMahon (Craddock), Wheater, Hines (Liddle), Grounds, Kennedy, Cattermole, A Johnson, Job (Walker), Maccarone, Nemeth.