  The development of the Internet of Drones (IoD) becomes vital because of a
proliferation of drone-based civilian or military applications. The IoD based
technological revolution upgrades the current Internet environment into a more
pervasive and ubiquitous world. IoD is capable of enhancing the
state-of-the-art for drones while leveraging services from the existing
cellular networks. Irrespective to a vast domain and range of applications, IoD
is vulnerable to malicious attacks over open-air radio space. Due to increasing
threats and attacks, there has been a lot of attention on deploying security
measures for IoD networks. In this paper, critical threats and vulnerabilities
of IoD are presented. Moreover, taxonomy is created to classify attacks based
on the threats and vulnerabilities associated with the networking of drone and
their incorporation in the existing cellular setups. In addition, this article
summarizes the challenges and research directions to be followed for the
security of IoD.
