phpwebftp -- "language" Local File Inclusion

Secunia reports:

phpWebFTP have a vulnerability, which can be exploited by
malicious people to disclose sensitive information.
Input passed to the “language” parameter in index.php isn’t
properly verified, before it is used to include files. This can be
exploited to include arbitrary files from local resources.
Successful exploitation requires that “magic_quotes_gpc” is
disabled.