Vulnerability Note VU#976484

RealFlex RealWin buffer overflow

Original Release date: 02 Dec 2008 | Last revised: 13 Jan 2009


RealFlex RealWin demo version contains a vulnerability in the way "FC_INFOTAG/SET_CONTROL" packets are processed.


RealFlex RealWin is SCADA server software that includes a Human Machine Interface (HMI) componant and runs on Microsoft Windows 2000 or XP. The demo version of RealWin contains a stack overflow in the way malicious "FC_INFOTAG/SET_CONTROL" packets are processed. According to Reversemode:

The bug is a classic stack overflow while processing a specially crafted FC_INFOTAG/SET_CONTROL packet. RealWin server accepts connections from FlewWin clients which use a propietary protocol. We can exploit this flaw from remote without having valid credentials.

Note that the non-demo version of RealWin has encryption protocol methods in place which calculate length of transmitted/received packets, preventing this buffer overflow.


This vulnerability could allow an unauthenticated, remote attacker to execute arbitrary code or cause a denial of service.


RealFlex has made a fixed version of the demo software available to address this issue. See for more information.

Restrict Access

Restrict network access to hosts that require connections to the demo version of RealWin. Do not allow access to RealWin from untrusted networks such as the internet.

Systems Affected (Learn More)

It appears that RealFlex (including RealWin and other products) was spun off from from DATAC (also known as: DCIL, DATAC Control International, Ltd., DATACONLINE) and that DATAC remains a licensed distributor of RealWin and other RealFlex products.

VendorStatusDate NotifiedDate Updated
DatacOnlineAffected13 Nov 200818 Dec 2008
DatacOnlineAffected-02 Dec 2008
RealFlexAffected-18 Dec 2008
If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental N/A N/A



This issue was reported by Ruben Santamarta of Reversemode .

This document was written by Chris Taschner.

Other Information

  • CVE IDs: CVE-2008-4322
  • Date Public: 26 Sep 2008
  • Date First Published: 02 Dec 2008
  • Date Last Updated: 13 Jan 2009
  • Severity Metric: 2.47
  • Document Revision: 15


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