The MHTML protocol handler in Microsoft Outlook Express 6 and Windows Mail in Windows Vista does not properly handle Content-Disposition "notifications," which allows remote attackers to obtain sensitive information from other Internet Explorer domains, aka "Content Disposition Parsing Cross Domain Information Disclosure Vulnerability."

The MHTML protocol handler in Microsoft Outlook Express 6 and Windows Mail in Windows Vista does not properly handle Content-Disposition "notifications," which allows remote attackers to obtain sensitive information from other Internet Explorer domains, aka "Content Disposition Parsing Cross Domain Information Disclosure Vulnerability."

Internet Explorer is vulnerable in handling MHTML (MIME Encapsulation of Aggregate HTML) protocol, which allows the download dialog box to be bypassed. Some versions of Outlook Express are affected because the vulnerability is contained in Outlook Express component used by Internet Explorer. When Internet Explorer accesses a website using MHTML (MIME Encapsulation of Aggregate HTML), Internet Explorer processes the contents as MHTML data, ignoring their actual content types, and it does not properly handle the Content-Disposition header field. This could cause a dialog box not to be displayed when downloading. The MHTML protocol handler is included in Outlook Express component, and Microsoft provides the fix for this componet.