Abstract- MANETs has become an important technology in recent years because of the rapid proliferation of wireless devices. MANETs are
highly vulnerable to attacks due to the open access medium, dynamically changing network topology and lack of centralized monitoring point.
The various attacks against mobile nodes are flooding, black hole, warm hole, packet dropping and Byzantine attack as well as Collaborative
attacks i.e. human attackers or criminal organizations etc. In this research paper, we study the Vulnerabilities of MANETs and address different
types of attacks against MANETs. Finally, we have addressed the future research direction.