VDA Labs Advisory: -------------------------- Ipswitch FTP XSS leads to FTP server compromise. The Vendor has been notified, and given the PoC. Synopsis: ------------ There is XSS vulnerability when the WS_FTP server logs client FTP commands. All user commands are logged. When the FTP command is invalid (error), special characters are converted to HTML chars (< = &lt;, > = &gt;<i>), and logged. However, when the FTP command is valid, there is no </I>sanity check. Thus, it is possible to inject HTML and Javascript into the log file. The WS_FTP administration interface (IIS web application written in ASP) has a view log option. When logs are viewed, it is possible to steal the administrator cookie, or even better, DIRECTLY create a new user (or admin) account for FTP server. We've created a little PoC that will create a new system administrator account when the admin view logs. The PoC is simple and injects an <iframe> that leads to another html file that creates the new account. Discovered by: ------------------ John Harwold, VDA Labs, LLC