The wireless LANs (WLANs) have become more prevalent and are widely deployed in many places such as corporate office conference rooms, industrial warehouses, campus, residences, caf? etc. The IEEE 802.11-based WLAN presents new challenges for network administrators and information security administrators alike. The security of a WLAN is very important, especially for applications hosting valuable information. Unlike the relative simplicity of wired Ethernet deployments, 802.11-based WLANs broadcast radio-frequency (RF) data for the client stations to receive. This presents new and complex security issues that involve augmenting the 802.11 standard. This paper critically reviews main security flaws of WEP, including short IV, key reuse, poor key management, and inappropriate RC4 and CRC-32 algorithms. It also describes a useful VPN security measure to enhance the level of security for the WLAN employing WEP.