Software Engineering Institute

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.