Microsoft researchers are currently investigating reports of targeted attacks that can be exploited through Microsoft Word, including Word 2007, using a buffer overflow error in the Jet Database Engine.

The code execution vulnerability is caused by a buffer overrun in the Microsoft Jet Database, or msjet40.dll. Security researchers say that the vulnerability could be exploited by an attacker who successfully enticed a user to open a malicious Word file constructed to load the specially-crafted database file using msjet40.dll.

A successful exploit would allow an attacker to gain the same privileges as the local user. In a Web-based exploit, an attacker could host a malicious Web site, including compromised Web sites and sites that accept user-provided content, with a specially-crafted Word file that exploited the vulnerability.

While users could not be forced to visit the malicious Web sites, an attacker could persuade them to visit the malware hosting sites by clicking on a malicious link embedded in an e-mail or IM message.

Accounts with reduced user rights could be less affected than users with elevated administrative privileges, security researchers say.

Customers using Microsoft Word 2000 Service Pack 3, Word 2002 Service Pack 3, Word 2003 Service Pack 2, Word 2003 Service Pack 3, Word 2007 and Word 2007 Service Pack 1 on Windows 2000, Windows XP or Windows Server 2003 Service Pack 1 are vulnerable to the potential attacks.

However, Windows Server 2003 Service Pack 2, Windows Vista and Windows Vista Service Pack 1 are protected from attack due to the fact that they include a version of the Jet Database Engine that does not contain the flaw.

Read more at CRN