This update resolves the "Outlook Express Restricted Sites zone bypass and file extension spoofing" security vulnerability in Outlook Express 5.5, and is discussed in Microsoft Security Bulletin MS01-058. Download now to prevent a malicious user from causing an attachment, when you open it, to be identified by a different name and extension.

This vulnerability could, in one scenario, enable an attacker to identify an executable file as a text file, so the file appears safe to open.

For more information about this vulnerability, read Microsoft Security Bulletin MS01-058. (This site is in English.)