This presentation discusses what to look for and how to go about exploiting game engines.
You can download it from the following link: https://packetstormsecurity.com/files/download/121687/Ferrante_Auriemma_Exploiting_Game_Engines.pdf
Source: https://packetstormsecurity.com/files/121687/Exploiting-Game-Engines-For-Fun-and-Profit.html