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

Low
Advisory ID
ZSL-2010-4948
Release Date
13 August 2010
Vendor
SmartCode Solutions - http://www.s-code.com
Affected Version
1.1.5.0
CVE
N/A
Tested On
Microsoft Windows XP Professional SP3 (EN), Windows Internet Explorer 8.0.6001.18702
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.

Description

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
Proof of Concept
Disclosure Timeline
12.11.2010Vendor releases version 1.1.7.0 to address this issue.
Credits
Vulnerability discovered by Gjoko Krstic
References
Changelog
13.08.2010Initial release
14.08.2010Added reference [1], [2] and [3]
16.08.2010Added reference [4], [5] and [6]
12.11.2010Added vendor status and added reference [7]
13.11.2010Added reference [8]