The Microsoft Jet Engine contains a stack buffer overflow, which can allow a remote, unauthenticated attacker to execute arbitrary code on a vulnerable system.
Microsoft Jet, or Joint Engine Technology, is a database engine that is used by several Microsoft products, including Access and Visual Basic. A Microsoft Access database uses the .MDB file extension by default. The Microsoft Jet Engine contains a stack buffer overflow in the handling of specially crafted database files.
Microsoft Word can link to Jet databases. In some cases, the database can be opened without prompting the user. This can allow Microsoft Word documents to be used as an attack vector for this vulnerability. Microsoft Outlook can also be used as an attack vector by either opening a specially crafted email message or by viewing such a message in the preview pane.
By convincing a user to open a specially crafted Word document or Jet database, such as a Microsoft Access .MDB file, a remote, unauthenticated attacker may be able to execute arbitrary code on a vulnerable system.
Apply an update
Block MDB files from being processed through your mail infrastructure
Impact of Workaround: Users will not be able to use Word as their e-mail editor or use Rich Text to read their e-mail
Using Group Policy
Domain administrators can use Group Policy to disable Word as the users e-mail editor. You do not have to restart the computer to implement this mitigation.
For information on using registry keys with a Group Policy see Using Administrative Template Files with Registry-Based Group Policy and Distributing Registry Changes.
Disable WordMail in Word 2003
Disable WordMail in Word 2002
Impact of Workaround: Users will not be able to use Word as their e-mail editor or use Rich Text by default to read their e-mail.
Restrict the Microsoft Jet Database Engine from running
To implement the workaround, enter the following command at a command prompt:
echo y| cacls "%SystemRoot%\system32\msjet40.dll" /E /P everyone:N
This vulnerability was publicly reported by cocoruder.
This document was written by Will Dormann.