A vulnerability that occurs because Internet Explorer does not properly determine an object type returned from a Web server in a popup window. It could be possible for an attacker who exploited this vulnerability to run arbitrary code on a user's system. If a user visited an attacker's Web site, it could be possible for the attacker to exploit this vulnerability without any other user action. An attacker could also craft an HTML–based e-mail that would attempt to exploit this vulnerability.

A vulnerability that occurs because Internet Explorer does not properly determine an object type returned from a Web server during XML data binding. It could be possible for an attacker who exploited this vulnerability to run arbitrary code on a user's system. If a user visited an attacker's Web site, it could be possible for the attacker to exploit this vulnerability without any other user action. An attacker could also craft an HTML–based e-mail that would attempt to exploit this vulnerability.

In addition, a change has been made to the method by which Internet Explorer handles Dynamic HTML (DHTML) Behaviors in the Internet Explorer Restricted Zone. It could be possible for an attacker exploiting a separate vulnerability (such as one of the two vulnerabilities discussed above) to cause Internet Explorer to run script code in the security context of the Internet Zone. In addition, an attacker could use Windows Media Player’s (WMP) ability to open URLs to construct an attack. An attacker could also craft an HTML-based e-mail that could attempt to exploit this behavior. To exploit these flaws, the attacker would have to create a specially formed HTML–based e-mail and send it to the user. Alternatively an attacker would have to host a malicious Web site that contained a Web page designed to exploit these vulnerabilities.