One of the things we do to make sure our customers have the best data on vulnerabilities in WordPress plugins is to monitor third party data on hacking attempts. Through that we recently came across a request for a file, /wp-content/plugins/wp-simple-cart/js/json2.js, from the plugin WP Simple Cart. That plugin is no longer in the WordPress Plugin Directory, which could have been due to it being removed for a security issue.

Seeing as the type of vulnerability that is probably the most likely to be exploited is an arbitrary file upload vulnerability, we started looking over the plugin for that type of vulnerability and we immediately found one. [Read more]