An unspecified function in the JavaScript implementation in Microsoft Internet Explorer creates and exposes a "temporary footprint" when there is a current login to a web site, which makes it easier for remote attackers to trick a user into acting upon a spoofed pop-up message, aka an "in-session phishing attack." NOTE: as of 20090116, the only disclosure is a vague pre-advisory with no actionable information. However, because it is from a well-known researcher, it is being assigned a CVE identifier for tracking purposes.