The document discusses security attacks in mobile ad hoc networks (MANETs). It begins by introducing MANETs and some of their unique characteristics that increase vulnerability to attacks. It then examines different types of attacks against MANET routing protocols in detail, including passive/active and external/internal attacks. Four main classes of routing attacks are identified: modification, interception, fabrication, and interruption attacks. Specific attacks under each class are discussed such as impersonation, black holes, wormholes, flooding, and lack of cooperation attacks. The document concludes that most common MANET routing attacks exploit routing messages in some way and future work will investigate security solutions classified based on the attack techniques.