Description
WordPress Plugin Filedownload is prone to multiple vulnerabilities, including open proxy, cross-site scripting and SQL injection vulnerabilities because it fails to properly verify and sanitize user-supplied input. An attacker may leverage these issues to hide attacks directed at a target site from behind vulnerable website, to execute arbitrary script code in the browser of an unsuspecting user in the context of the affected site, to steal cookie-based authentication credentials, to compromise the application, access or modify data or to exploit vulnerabilities in the underlying database. WordPress Plugin Filedownload version 1.4 is vulnerable; prior versions may also be affected.
Remediation
Edit the source code to ensure that input is properly verified and sanitised or disable the plugin until a fix is available
References
http://www.vapidlabs.com/advisory.php?v=140
https://packetstormsecurity.com/files/132959/WordPress-Filedownload-1.4-Open-Proxy.html