With the advent of sophisticated technology and associated indubitable benefits, the wireless network is gaining popularity day by day. Still there exists numerous security challenges and to overcome these, different researches are being carried on. This suggests that the wireless security is still in nascent stage and requires further development. The new wireless technologies like Wireless Body Area Network, thus provides tough challenges to security professionals. Wireless Body Area Network (WBAN) technology has been center of attraction in e-health system. In this system, data security breach might even cost lives of patients, so it alarms the need for highly reliable security system. This thesis is pivoted on security vulnerabilities in Wireless Body Area Network and mitigation tools and techniques to get rid of them. The study corresponds with security concern of Adaptive Security for Smart Internet of Things in e-Health (ASSET)project that has been launched by Norwegian Research Center. The thesis enlightens ASSET with different types of security threats that exist in wireless network, specifically on WBAN. It provides ASSET an infrastructure setup to facilitate security analysis in its network environment. ZigBee network, an instance of the WBAN is deployed as experimental platform. Experiments are performed in the OPNET network simulator and ASSET laboratory, consisting of different types of sensor devices. The study shows DoS attack and message replay attack are easily accomplished and prevalent in WBAN. However, security system to prevent them are under development. Finally, the thesis provides ASSET a platform to perform security analysis on WBAN deployment.