Portcullis Security Advisory 06-062


Vulnerable System:

SurgeFTP


Vulnerability Title:

SurgeFTP is vulnerable to Cross-site Scripting(XSS).


Vulnerability Discovery And Development: 

Portcullis Security Testing services discovered this vulnerability.  
Further research was then carried out.


Credit For Discovery:

Nico Leidecker - Portcullis Computer Security Ltd.


Affected systems: 

Version 2.3a1 Linux and probably other platforms.


Details:

SurgeFTP provides a web interface for managing mirrored servers. The state of 
every last mirroring process is displayed in the overview screen. If SurgeFTP
receives a server response where the first characters are not the numeric 
status code, an error message is printed which also includes the received 
message from the mirrored server. SurgeFTP fails to sanitise HTML and script 
code from that message.                                                       


Impact:

An attacker can gain root access on the server. In order to achieve that, he 
will have the ability to execute script code that creates an FTP user who can 
access the real root directory and acts without dropping privileges. In one 
scenario, for the next step, the attacker accesses the vulnerable host via FTP 
and uploads a modified crontab file with the intention of executing a command 
which binds a shell to a port.


Exploit:

The proof of concept exploit code is available.


Vendor Status:

Vendor notified. The vulnerability has been fixed.


Copyright: 

Copyright © Portcullis Computer Security Limited 2005, All rights reserved 
worldwide. 

Permission is hereby granted for the electronic redistribution of this 
information. It is not to be edited or altered in any way without the express 
written consent of Portcullis Computer Security Limited.


Disclaimer: 

The information herein contained may change without notice. Use of this 
information constitutes acceptance for use in an AS IS condition. There are NO 
warranties, implied or otherwise, with regard to this information or its use. 
Any use of this information is at the user's risk. In no event shall the 
author/distributor (Portcullis Computer Security Limited) be held liable for 
any damages whatsoever arising out of or in connection with the use or spread 
of this information.