Wearable Technology also called wearable gadget, is acategory of technology devices with low processing capabilities that can be worn by a user with the aim to provide information and ease of access to the master devices its pairing with. Such examples are Google Glass and Smart watch. The impact of wearable technology becomes significant when people start their invention in wearable computing, where their mobile devices become one of the computation sources. However, wearable technology is not mature yet in term of device security and privacy acceptance of the public. There exists some security weakness that prompts such wearable devices vulnerable to attack. One of the critical attack on wearable technology is authentication issue. The low processing due to less computing power of wearable device causethe developer's inability to equip some complicated security mechanisms and algorithm on the device.In this study, an overview of security and privacy vulnerabilities on wearable devices is presented.