Outlook 2000 and 2002 provide the option to use Microsoft Word as the e-mail editor when creating and editing e-mail in either Rich-Text or HTML format. A security vulnerability exists when Outlook is configured this way and the user forwards or replies to a mail from an attacker.
The vulnerability results from a difference in the security settings that are applied when displaying a mail versus editing one. When Outlook displays an HTML e-mail, it applies Internet Explorer security zone settings that disallow scripts from being run. However, if the user replies to or forwards a mail message and has selected Word as the e-mail editor, Outlook opens the mail and puts the Word editor into a mode for creating e-mail messages. Scripts are not blocked in this mode.
|