The Math.random function in the JavaScript implementation in Mozilla Firefox 3.5.x before 3.5.10 and 3.6.x before 3.6.4, and SeaMonkey before 2.0.5, uses a random number generator that is seeded only once per browser session, which makes it easier for remote attackers to track a user, or trick a user into acting upon a spoofed pop-up message, by calculating the seed value, related to a “temporary footprint” and an “in-session phishing attack.”

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.