Vulnerability Note VU#205073

Gesytec Easylon OPC Server fails to properly validate OPC server handles

Original Release date: 14 Dec 2007 | Last revised: 10 Jan 2008


The Gesytec Easylon OPC Server contains a vulnerability that may allow a remote attacker to execute arbitary code or cause a denial-of-service condition.


OLE for Process Control (OPC) is a specification for a standard set of OLE COM objects used in the process control and manufacturing fields. OPC servers are often used in control systems to consolidate field and network device information.

The Gesytec Easylon OPC Server fails to properly validate server handles. This vulnerability may be triggered by an attacker with access to the server's OPC interface.


An attacker with access to the Gesytec Easylon OPC Server may be able to arbitrarily access server process memory, potentially allowing that attacker to execute arbitrary code or cause a denial of service.


Gesytec has released version 2.3.44 of the Easylon OPC server to correct this vulnerability.

Restrict access to the server

Until a fixed version of the server can be deployed, consider restricting remote access to the server to only trusted hosts. You can restrict the access by using firewalls or by only connecting the server to private networks that are not connected to systems with Internet access.

Critical systems (such as industrial control systems) should either not be connected to corporate networks with Internet connectivity or should be connected in a controlled way. If connecting the control system network to the corporate network is necessary, a firewall should be deployed to monitor and control traffic flow between the two networks.

Systems Affected (Learn More)

VendorStatusDate NotifiedDate Updated
GesytecAffected13 Jan 200710 Sep 2007
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 vulnerability was reported by NeutralBit

This document was written by Jeff Gennari and Ryan Giobbi.

Other Information

  • CVE IDs: CVE-2007-4473
  • Date Public: 14 Dec 2007
  • Date First Published: 14 Dec 2007
  • Date Last Updated: 10 Jan 2008
  • Severity Metric: 4.50
  • Document Revision: 24


If you have feedback, comments, or additional information about this vulnerability, please send us email.