Barracuda CudaTel 2.6.02.040 Cross Site Scripting

[Matt]

Description : Barracuda CudaTel version 2.6.02.040 suffers from a cross site scripting vulnerability.

Author : Benjamin Kunz Mejri

Source : Barracuda CudaTel 2.6.02.040 Cross Site Scripting ? Packet Storm

Code :

Title:
======
Barracuda CudaTel 2.6.02.040 - Client Side Cross Site Scripting Vulnerability


Date:
=====
2013-07-15


References:
===========
http://www.vulnerability-lab.com/get_content.php?id=776

BARRACUDA NETWORK SECURITY ID: BNSEC-807


VL-ID:
=====
776


Common Vulnerability Scoring System:
====================================
2.1


Introduction:
=============
Designed to enable seamless voice and video communication, the CudaTel Communication Server is an easy-to-use, 
affordable, next-generation phone system for businesses. CudaTel Communication Server s enterprise-class 
feature set includes Voice over IP (VoIP) PBX services, conferencing, follow-me, automated attendant services, 
and more, controlled by an easy-to-use Web interface. CudaTel Communication Server is compatible with any SIP 
device and provider, and can be pre-configured for use with both analog and digital telephone networks. Powerful, 
Complete Solution With an expansive feature set and and no per user or phone licensing fees, the CudaTel 
Communication Server is equipped and priced for organizations of any size. Native High Definition audio support 
and integrated phone line (TDM) hardware produces an unparalleled audio experience. VOIP encryption protects calls 
from hackers and digital eavesdroppers.

(Copy of the Vendor Homepage: http://www.barracudanetworks.ca/cudatel.aspx )


Abstract:
=========
The Vulnerability Laboratory Research Team discovered a client side web vulnerability in Barracuda Networks CudaTel v2.6.002.040 appliance application.


Report-Timeline:
================
2012-11-26:  Researcher Notification & Coordination
2012-11-27:  Vendor Notification
2012-12-01:  Vendor Response/Feedback
2013-04-03:  Vendor Fix/Patch
2012-07-15:  Public Disclosure


Status:
========
Published


Affected Products:
==================
Barracuda Networks
Product: CudaTel - Communication Server 2.6.002.040


Exploitation-Technique:
=======================
Remote


Severity:
=========
Medium


Details:
========
A client side input validation vulnerability is detected  in Barracuda Networks CudaTel v2.6.002.040 appliance application.
The non-persistent vulnerability allows remote attackers to manipulate website links to provoke malicious client side (application-side) requests.

The secound vulnerability (client side) is located in the `error:Internal Error` exception handling. When remote attackers provoke to 
load an invalid request the exception-handling will display the earlier inserted bbx_hostname (malicious) web context (exp. script codes). 
The attacker can use the vulnerable bbx_backup_site_host parameter of the test connection listing module to provoke an evil application 
exception-handling request.

Successful exploitation of the vulnerability results in client side phishing, client side session hijacking and client side 
external redirects to malware or evil websites. Exploitation of the vulnerability requires medium application user interaction.

Vulnerable Section(s):
        [+] Test - Connection

Vulnerable Module(s):
        [+] Exception-handling [Internal Error] - Listing

Vulnerable Parameter(s):
        [+] bbx_backup_site_host


Proof of Concept:
=================
The vulnerability can be exploited by remote attackers with low or medium required user interaction and without privileged application user account.
For demonstration or reproduce ...


Review: Exception-handling [Internal Error] - Listing [bbx_backup_site_host]

<pre>--- 
error: "Internal error.\n[backup] 
Can't connect to >\"<iframe src="test3-Dateien/a.htm" href="http://vuln-lab.com/?content-type=text/html">http://vuln-lab.com</a>>"
</pre></body></html></iframe></pre>


PoC:
http://cudatel.ptest.cudasvc.com/gui/backup/test
?_=1353975862209&bbx_backup_site_id=2&bbx_backup_site_type=ftp
&bbx_backup_site_host=%3E%22%3Ciframe%20src=http://vulnerability-lab.com%3E&bbx_backup_site_port=8&bbx_backup_site_user=BENJAMINKM
&bbx_backup_site_path=%2F+%26+echo+%3E+%2Fdata%2Fsounds%2Fmusic%2F8%2F2a10577f-6764-4368-8571-44d42e4695ff


Solution:
=========
The vulnerability can be patched by parsing the vulnerable bbx_backup_site_host parameter request.
Parse the internal error exception-handling when processing to display the error string of the requested parameter. (error context)

2013-04-03:  Vendor Fix/Patch

Note: Barracuda Networks provided a download in the customer section but also automatic update to patch the issue in the appliance series.


Risk:
=====
The security risk of the client side input validation vulnerability is estimated as medium(-) because of the main location in the exception-handling.


Credits:
========
Vulnerability Laboratory [Research Team] - Benjamin Kunz Mejri (bkm@vulnerability-lab.com)