Medy Elito's first goal of the season looked to have secured the points for the hosts, but former Norwich strike Cureton pounced for his 10th goal of the campaign.
The 37-year-old centre-forward equalised six minutes after the break to rub salt into the wound after Michael Spillane missed a penalty.
Elito won the penalty for John Still's side after he was sent tumbling by a challenge from goalkeeper Artur Krysiak.
But Spillane blasted over and that allowed the in-form Cureton to level with a cool finish from the edge of the box.
The draw ended the Grecians' three-game losing run, during which they failed to score.