The increasing popularity of Flying Ad hoc Networks (FANETs) and the growing number of their applications necessitate the exploration of security vulnerabilities and attacks. Over time, FANETs have expanded into various sectors. They are used in search and rescue, surveillance, and transportation. These applications benefit both commercial and military domains. However, FANETs face growing security threats. The attackers can exploit vulnerabilities, causing unpredictable consequences. In this paper, we first conducted a study on various vulnerabilities associated with FANETs. Then, this paper proceeds to present various security attacks that compromise the integrity and security of FANETs. We present a novel classification of vulnerabilities and attacks based on communication and operations of FANETs in this paper. Finally, the paper concludes by highlighting future research directions in the domain of security in FANETs.