Microsoft Internet Explorer (IE) does not properly determine the source of script used in URLs. An attacker could exploit this vulnerability to evaluate script in different security domains. By causing script to be evaluated in the Local Machine Zone, the attacker could execute arbitrary code with the privileges of the user running IE.
IE uses a cross-domain security model to maintain separation between browser frames from different sources. This model is designed to prevent code in one domain from accessing data in a different domain. From Microsoft Security Bulletin MS03-048:
One of the principal security functions of a browser is to ensure that browser windows that are under the control of different Web sites cannot interfere with each other or access each other's data, while allowing windows from the same site to interact with each other. To differentiate between cooperative and uncooperative browser windows, the concept of a "domain" has been created. A domain is a security boundary - any open windows within the same domain can interact with each other, but windows from different domains cannot. The cross-domain security model is the part of the security architecture that keeps windows from different domains from interfering with each other.
This URL will display an alert dialog with the contents of the HTTP cookie for the current site:
By convincing a victim to view an HTML document (web page, HTML email), an attacker could evaluate script in a different security domain than the one containing the attacker's document. By causing script to be evaluated in the Local Machine Zone, the attacker could execute arbitrary code with the privileges of the user running IE.
This vulnerability was publicly reported by Liu Die Yu. Thanks to Microsoft and Thor Larholm for information used in this document.
This document was written by Art Manion.
|Date First Published:||2003-11-19|
|Date Last Updated:||2003-12-05 19:11 UTC|