Radio propagation has broadcast nature due to which the wireless air interface is open and accessible to both authorized and illegitimate users. Wireless network attacks are classified on the basis of access control, authentication, availability, confidentiality and integrity as attacks can appear in the form of Access, channel assignment and at the source end. So security plays an important role in wireless networks. Due to the open nature of public WiFi network it is most attractive and easy target of attacker to steal confidential information of users using Evil Twin Attack by creating Rogue Access Point. The presence of this type of access point in the wireless network increases the loss of critical information. In this paper, we go through different types of security threats in wireless network. We also discuss the Evil Twin Attack. We discuss security solutions proposed by researchers.