Unauthenticated remote code execution on D-Link ShareCenter products

Type securityvulns
Reporter Securityvulns
Modified 2012-02-13T00:00:00


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 (roberto.paleari@emaze.net)

[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,

* 02/01/2012 - No response from the vendor. The author re-sent the last

* 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 info@emaze.net 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.