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CERT Coordination Center

Microsoft HTML Help Workshop buffer overflow

Vulnerability Note VU#124460

Original Release Date: 2006-02-13 | Last Revised: 2006-02-14


A buffer overflow in Microsoft HTML Help Workshop may allow a remote attacker to execute arbitrary code on a vulnerable system.


Microsoft HTML Help provides a standard help system for the Windows operating system. HTML Help Workshop is a component of the software development kit for HTML Help. A lack of validation on the Contents file field within HTML Help Workshop Project files headers may allow a stack-based buffer overflow to occur. Note that Microsoft HTML Help Workshop is not installed by default on any version of Microsoft Windows.

Exploit code for this vulnerability is publicly available.


By persuading a user to access a specially crafted HTML Help Workshop Project files (.hhp), a remote attacker may be able to execute arbitrary code.


We are unaware of a practical solution to this problem, however we suggest the following workaround to reduce the chances of exploitation:

Do not access HTML Help Workshop Project files from untrusted sources

Exploitation occurs if a user has the HTML Help SDK installed and accesses a specially crafted HTML Help Workshop Project file. By only accessing Help Workshop Project files from known and trusted sources, the chances of exploitation are reduced.

Vendor Information


Microsoft Corporation Affected

Updated:  February 13, 2006



Vendor Statement

We have not received a statement from the vendor.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

CVSS Metrics

Group Score Vector



This vulnerability was reported by bratax.

This document was written by Jeff Gennari.

Other Information

CVE IDs: CVE-2006-0564
Severity Metric: 17.08
Date Public: 2006-02-06
Date First Published: 2006-02-13
Date Last Updated: 2006-02-14 18:19 UTC
Document Revision: 51

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