WordPress wins the dubious distinction of Mass 0wnage Pwnie Award for an unbelievable number of WordPress vulnerabilities, over 140 as of today.
It seems like hardly a week goes by without a new vulnerability in WordPress or one of its many plugins. Many of them are actively being exploited to own popular WordPress blogs and use them to serve spam or client-side exploits to unsuspecting visitors. The popularity of WordPress combined with the abysmal security practices of WordPress plugin developers places the entire Internet at risk and is worthy of a nomination.