Outlook-Word Vulnerability Could Allow Code Execution

Organizations running Microsoft's Outlook e-mail client face a new security vulnerability if some users choose Word as their default e-mail editor.

Microsoft classifies the newly discovered vulnerability as a moderate risk to client systems, and the company has a patch available at

A feature of Outlook 2000 and Outlook 2002 allows users to select Microsoft Word as the e-mail editor when writing or editing e-mail in Rich Text or HTML. A vulnerability means that when Outlook is used that way, replying or forwarding to e-mail from a malicious user could execute scripts that run in the security context of the user.

Microsoft uses different security settings for displaying e-mail versus editing e-mail. Outlook displays HTML e-mail by applying Internet Explorer security zone settings that prevent scripts from running. But if the user replies or forwards the message, Outlook opens the e-mail and passes the message to the Word editor, which doesn't block scripts.

About the Author

Scott Bekker is editor in chief of Redmond Channel Partner magazine.