  Low Power Wide Area Network (LPWAN) technologies like the Long Range Wide
Area Network (LoRaWAN) standard provide the foundation of applications
realizing communication and intelligent interaction between almost any kind of
object. These applications are commonly called Smart Cities and the Internet of
Things (IoT). Offering the potential of great benefits for mankind, these
applications can also present a significant risk, especially when their
security is compromised. This paper's work analyzes the possibility of two
particular scenarios of impersonating a LoRaWAN gateway combining existing
attacks. Impersonated gateways are of use when exploiting vulnerabilities
already shown by other researchers. We give a basic overview about LoRaWAN, the
Semtech Packet Forwarder protocol, attacks needed to perform the impersonation,
and assumptions made. We explain our attack and propose countermeasures to
increase the security of LoRaWAN networks. We show a gateway impersonation is
possible in particular circumstances but can be detected and prevented.
