D-Link ShareCenter Remote Code Execution

`Unauthenticated remote code execution on D-Link ShareCenter products  
====================================================================  
  
[ADVISORY INFORMATION]  
Title: Unauthenticated remote code execution on D-Link ShareCenter products  
Release date: 08/02/2012  
Last update: 08/02/2012  
Credits: Roberto Paleari, Emaze Networks S.p.A ([email protected])  
  
[VULNERABILITY INFORMATION]  
Class: Authentication bypass, remote code execution  
  
[AFFECTED PRODUCTS]  
We confirm the presence of the security vulnerabilities on the following  
products/firmware versions:  
  
* DNS-320, firmware version 2.00.1217.2010  
* DNS-320, firmware version 2.01.0512.2011  
* DNS-320, firmware version 2.02.0901.2011  
* DNS-320, firmware version 2.02.0923.2011  
* DNS-325, firmware version 1.01.1217.2010  
  
Other models and firmware versions are probably also vulnerable, but they were  
not checked.  
  
[VULNERABILITY DETAILS]  
D-Link ShareCenter devices suffer from a publicly-known authentication bypass  
issue that, according to an existing advisory[1], can be exploited to cause a  
Denial-of-Service.  
  
In this advisory we shed some light over the impact of this issue. In  
particular, the device implements almost no authentication checks on HTTP  
requests for any existing CGI script (i.e., all the CGIs under the /cgi  
directory). As an example, an attacker may retrieve the device model & firmware  
version by accessing the following resources:  
  
http://<device IP address>/cgi-bin/discovery.cgi  
http://<device IP address>/cgi-bin/system_mgr.cgi?cmd=get_firm_v_xml  
  
Besides information gathering, this vulnerability can be exploited to gain full  
control of the device. In particular, an undocumented functionality permits to  
execute arbitrary commands, displaying their output in the generated HTML  
page. As an example, to execute the "ls" command, an attacker can access the  
following URL:  
  
http://<device IP address>/cgi-bin/system_mgr.cgi?cmd=cgi_sms_test&command1=ls  
  
Even in this case, no authentication checks are performed.  
  
References:  
[1] http://www.securityfocus.com/bid/50902/info  
  
[REMEDIATION]   
We are not aware of an updated firmware that corrects the issue described in  
this advisory.  
  
[DISCLOSURE TIME-LINE]  
* 22/12/2011 - Initial vendor contact.  
  
* 27/12/2011 - Vendor replied.  
  
* 28/12/2011 - Emaze asks for a technical contact to discuss the details of  
the vulnerability. Publication date set to January 18th,  
2012.  
  
* 02/01/2012 - No response from the vendor. The author re-sent the last  
e-mail.  
  
* 17/01/2012 - Still no reply from the vendor. The author re-sent the  
e-mail, again.  
  
* 31/01/2012 - Sent another e-mail to vendor, to inform about the intention  
to publicly disclose the vulnerability within February, 3rd.  
  
* 08/02/2012 - Still no reply. Disclosure.  
  
[COPYRIGHT]  
Copyright(c) Emaze Networks S.p.A 2012, All rights reserved worldwide.  
Permission is hereby granted to redistribute this advisory, providing that no  
changes are made and that the copyright notices and disclaimers remain intact.  
  
Emaze Networks has updated ipLegion, its vulnerability assessment platform, to  
check for this vulnerability. Contact [email protected] to have more information  
about ipLegion.  
  
[DISCLAIMER]  
Emaze Networks S.p.A is not responsible for the misuse of the information  
provided in our security advisories. These advisories are a service to the  
professional security community. There are NO WARRANTIES with regard to this  
information. Any application or distribution of this information constitutes  
acceptance AS IS, at the user's own risk. This information is subject to change  
without notice.  
`