Vulnerability Note VU#976484

RealFlex RealWin buffer overflow

Overview

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

I. Description

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.

II. Impact

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

III. Solution

Update

RealFlex has made a fixed version of the demo software available to address this issue. See http://www.realflex.com/download/form.php 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

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.

Vendor	Status	Date Notified	Date Updated
DatacOnline	Vulnerable	2008-11-13	2008-12-18
DatacOnline	Vulnerable		2008-12-02
RealFlex	Vulnerable		2008-12-18

References

http://secunia.com/advisories/32055/
http://www.realflex.com/products/realwin/realwin.php
http://www.dataconline.com/software/realwin.php
http://www.dataconline.com/profile/profile.php
http://www.realflex.com/profile/history.php
http://reversemode.com/index.php?option=com_content&task=view&id=55&Itemid=1

Credit

This issue was reported by Ruben Santamarta of Reversemode.

This document was written by Chris Taschner.

Other Information

Date Public:	2008-09-26
Date First Published:	2008-12-02
Date Last Updated:	2009-01-13
CERT Advisory:
CVE-ID(s):	CVE-2008-4322
NVD-ID(s):	CVE-2008-4322
US-CERT Technical Alerts:
Metric:	2.47
Document Revision:	15

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Produced 2008 by US-CERT, a government organization
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