Sensor networks (WSN) is an emerging technology and a hot research topic among researchers due to their flexibility and independence of network infrastructures, such as base stations. It can also be used for applications such as building, traffic surveillance, and habitat monitoring and many scenarios. It is flexible to go through physical partition and it avoids lot of wiring. The major challenges one facing today in wireless sensor network is security. It is because we cannot control propagation of waves and they are also limited by their computing power and energy constraints. This paper discusses about several varieties of attacks in wireless sensor network.Keywords: Wireless sensor network, security, security attack
