phpWebFTP enables connections to FTP servers, even behind a firewall not allowing traffic. phpWebFTP bypasses the firewall by making a FTP connection from your webserver to the FTP server and transfering the files to your webclient over the http protocol
Issue: PhpWebftp is prone to multiple XSS vulnerability .An attacker may leverage this issue to have arbitrary script code executed in the browser of an unsuspecting user in the context of the affected site. This may help the attacker steal cookie-based authentication credentials and launch other attacks.the exploit is tested on PhpWebFtp v2.3.
Proof of Concept
XSS is possible via malicious arguments passed on the web browser using POST Method relative to the path of phpWebftp ie. http://www.anysite.com/PhpWebFtp/index.php?
Further XSS Details and Xploits :