Microsoft Word is affected by a buffer overflow vulnerability. This issue is due to a failure in the application to do proper bounds checking on user-supplied data. Microsoft has not specified exactly where the error may occur. This could result in execution of arbitrary code in the context of a user who opens the malicious document. Internet Explorer is a likely attack vector as Word may be opened to handle the document when the user clicks a link.
Do not accept or execute files from untrusted or unknown sources.
Users should be wary of opening any files that originate from an untrusted or unfamiliar source.
Run all software as a nonprivileged user with minimal access rights.
Running the affected application as a user with minimal access rights may greatly prove to help mitigate the impact of successful exploitation.
Microsoft has released updates to address this issue in supported versions of affected software. UPDATE: Fixes are available for Microsoft Word 2003 Viewer.