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             AUSCERT External Security Bulletin Redistribution

           Schneider Electric OPC Factory Server Buffer Overflow
                               7 April 2014


        AusCERT Security Bulletin Summary

Product:           Schneider Electric OPC Factory Server
Publisher:         US-CERT
Operating System:  Windows
Impact/Access:     Denial of Service -- Unknown/Unspecified
Resolution:        Patch/Upgrade
CVE Names:         CVE-2014-0789  

Original Bulletin: 

Comment: Exploits that target this vulnerability are publicly available.

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Advisory (ICSA-14-093-01)

Schneider Electric OPC Factory Server Buffer Overflow

Original release date: April 03, 2014

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Researcher Wei Gao, formerly of IXIA, has identified a buffer overflow 
vulnerability in the Schneider Electric OPC Factory Server (OFS) application. 
Schneider Electric has produced a patch that mitigates this vulnerability. 
Wei Gao has tested the patch to validate that it resolves the vulnerability.

This vulnerability could be exploited remotely.


Schneider Electric reports that the vulnerability affects the following 
versions of OFS:

- - TLXCDSUOFS33 – V3.5 and previous,
- - TLXCDSTOFS33 – V3.5 and previous,
- - TLXCDLUOFS33 – V3.5 and previous,
- - TLXCDLTOFS33 – V3.5 and previous, and
- - TLXCDLFOFS33 – V3.5 and previous.


A successful exploitation will cause the server to reboot resulting in a 
denial of service.

Impact to individual organizations depends on many factors that are unique to 
each organization. ICS-CERT recommends that organizations evaluate the impact 
of this vulnerability based on their operational environment, architecture, 
and product implementation.


Schneider Electric corporate headquarters is located in Paris, France, and 
maintains offices in more than 100 countries worldwide.

These products are industrial active energy management control products, 
deployed across several sectors including the Energy, Water and Wastewater 
Systems, Commercial Facilities, Government Facilities, Food and Agriculture, 
and Transportation Systems. Schneider Electric estimates that these products 
are used primarily in the United States and North America.




Incorrect parsing in the OPC Automation 2.0 Server Object (ActiveX) can result 
in a buffer overflow error. The vulnerability is caused by parsing long 
arguments in functions.

CVE-2014-0789 [b] has been assigned to this vulnerability. A CVSS v2 base 
score of 5.0 has been assigned; the CVSS vector string is 
(AV:N/AC:L/Au:N/C:N/I:N/A:P). [c]



This vulnerability could be exploited remotely.


Exploits that target this vulnerability are publicly available.


An attacker with a low skill would be able to exploit this vulnerability.


Schneider Electric has developed a patch to resolve this issue. In order to 
patch the installation in the field, install OFS V3.5SP1, available on 
Schneider Electric’s web site at the following URL:

OFS V3.5SP1 includes a patched version of the OLE2T macro from Microsoft to 
resolve the issue.

For more information regarding this issue, please see the security 
announcements affecting the OPC Factory Server on Schneider Electric’s web 
site at the following URL:

ICS-CERT encourages asset owners to take additional defensive measures to 
protect against this and other cybersecurity risks.

- - Minimize network exposure for all control system devices and/or systems, and 
ensure that they are not accessible from the Internet.
- - Locate control system networks and remote devices behind firewalls, and 
isolate them from the business network.
- - When remote access is required, use secure methods, such as Virtual Private 
Networks (VPNs), recognizing that VPN is only as secure as the connected 

ICS-CERT also provides a section for control systems security recommended 
practices on the ICS-CERT web page at: http://ics-cert.us-cert.gov/content/recommended-practices. 
Several recommended practices are available for reading and download, 
including Improving Industrial Control Systems Cybersecurity with 
Defense-in-Depth Strategies. ICS-CERT reminds organizations to perform proper 
impact analysis and risk assessment prior to deploying defensive measures.

Additional mitigation guidance and recommended practices are publicly 
available in the ICS‑CERT Technical Information Paper, 
ICS-TIP-12-146-01B--Targeted Cyber Intrusion Mitigation Strategies, that is 
available for download from the ICS-CERT web site (http://ics-cert.us-cert.gov/).

Organizations observing any suspected malicious activity should follow their 
established internal procedures and report their findings to ICS-CERT for 
tracking and correlation against other incidents.

[a]. CWE-122: Heap-based Buffer Overflow, http://cwe.mitre.org/data/definitions/122.html, 
web site last accessed April 03, 2014.
[b]. NVD, http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2014-0789, 
NIST uses this advisory to create the CVE web site report. This web site will 
be active sometime after publication of this advisory.
[c]. CVSS Calculator, http://nvd.nist.gov/cvss.cfm?version=2&vector=AV:N/AC:L/Au:N/C:N/I:N/A:P, 
web site last accessed April 03, 2014.

Contact Information

For any questions related to this report, please contact ICS-CERT at:

Email: ics-cert@hq.dhs.gov
Toll Free: 1-877-776-7585
International Callers: (208) 526-0900

For industrial control systems security information and incident reporting: 

ICS-CERT continuously strives to improve its products and services. You can 
help by choosing one of the links below to provide feedback about this product.

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