Protecting Your Network from the Wi-Fi Protected Setup Security Hole.
This article is basically about the vulnerability of computer systems through the Wi-Fi router. It tells how the most widely used (security system for routers) Wi-Fi Protected Access (WPA or WPA2), have a security hole affecting most wireless routers. People with the right tools can hack your network and connect to wireless Internet access, possibly connect to your computers, and snoop on your network traffic to perhaps capture your passwords and hijack your online accounts. This security hole comes from the Wi-Fi Protected Setup (WPS) feature which actually was developed to make securing and connecting Wi-Fi devices easier and has been widely used in most of the routers since 2007. The method of PIN makes it insecure as it provides the hacker ample of opportunities to try and ultimately recognize/reveal the 8-digit PIN. This security hole does not patch up even when you turn off the WPS and can be attacked. So, if the system has WPS then it is a reason to worry otherwise the ‘hole’ does not apply to you. But, still you can protect your system by using updated firmware or after-market router. Also, the ‘hole’ vulnerability is not applicable if you are not using Personal or PSK mode of WPA2 because WPS comes into picture in Personal mode only.
 So, if this vulnerability exists, one should be careful about the choice of Wi-Fi system, as wrong choice can lead to intrusion into your personal information. The 8-digit PIN or the paraphrase which most people think to be sufficiently secure is actually not that secure. One should always remain updated with the latest technical developments so as to avoid ‘outsiders’. As long as the router is used for business (Enterprise mode of WAP2) there is no threat of security hole. Otherwise, sufficient precautions have to be taken.
http://www.ciscopress.com/articles/article.asp?p=1847302