The vulnerability discussed is MS02-068, specifically related to an "external object caching" issue. Discovered by GreyMagic Software. Microsoft rates the vulnerability's severity as "Moderate", though the author disagrees, arguing it is more severe. The vulnerability could allow attackers to perform any action the user can perform on the local computer, including reading and changing files, forcefully placing arbitrary files, and invoking any executable with or without parameters. Microsoft initially downplayed the severity, suggesting attackers could not do much due to a lack of parameter passing ability, but this was criticized as inaccurate. As of the date of the post, there are 18 unpatched publicly known vulnerabilities in Internet Explorer, with 6 being considered severe by the author. A link to a list of unpatched vulnerabilities is provided: http://www.pivx.com/larholm/unpatched/