Vulnerability Note VU#468798

SISCO OSI stack fails to properly validate packets

Original Release date: 20 Sep 2006 | Last revised: 21 Jul 2008


A vulnerability exists in the SISCO OSI stack for Windows. If successfully exploited, an attacker could cause a denial-of-service condition.


Inter-control Center Communications Protocol (ICCP)

The Inter-control Center Communications Protocol (ICCP) is a protocol that is used to communicate data between control centers that operate SCADA networks.

Manufacturing Message Specification (MMS)

According to SISCO,

MMS (Manufacturing Message Specification) is an internationally standardized messaging system for exchanging real-time data and supervisory control information between networked devices and/or computer applications in a manner that is independent of: 1) the application function being performed or 2) the developer of the device or application. MMS is an international standard (ISO 9506) that is developed and maintained by Technical Committee Number 184 (TC184), Industrial Automation, of the International Organization for Standardization (ISO).

ISO Transport Service over TCP (TPKT, RFC 1006)

RFC 1006 specifies how to run the OSI transport protocol on top of TCP/IP. In the layered protocol model, RFC 1006 is situated between the TCP and OSI transport layers.

The Problem

The SISCO OSI stack for Windows fails to properly handle malformed packets. A remote, unauthenticated attacker may be able to exploit this vulnerability to cause a denial-of-service condition. The SISCO OSI stack for Windows is used in the MMS-EASE, ICCP Toolkit for MMS-EASE, AX-S4 MMS, and AX-S4 ICCP products.


A remote, unauthenticated attacker may be able to cause a denial-of-service condition.



SISCO has addressed this vulnerability. Contact them for a list of unaffected or patched software. According to SISCO, the following versions of software are affected:

SISCO Vulnerability Announcement

Restrict Access

Restrict remote access to only trusted hosts by using firewalls or only connecting them to private networks.

Systems Affected (Learn More)

VendorStatusDate NotifiedDate Updated
SISCO - Systems Integration Specialists Company, Inc.Affected23 Jun 200618 Sep 2006
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 SISCO.

This document was written by Ryan Giobbi, based on information from SISCO.

Other Information

  • CVE IDs: CVE-2005-4812
  • Date Public: 25 Feb 2005
  • Date First Published: 20 Sep 2006
  • Date Last Updated: 21 Jul 2008
  • Severity Metric: 0.92
  • Document Revision: 59


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