The WebBrowser ActiveX control, or the Internet Explorer HTML rendering engine (MSHTML), as used in Internet Explorer 6, allows remote attackers to execute arbitrary code in the Local Security context by using the showModalDialog method and modifying the location to execute code such as Javascript, as demonstrated using (1) delayed HTTP redirect operations, and an HTTP response with a Location: header containing a "URL:" prepended to a "ms-its" protocol URI, or (2) modifying the location attribute of the window, as exploited by the Download.ject (aka Scob aka Toofer) using the ADODB.Stream object.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A519
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A241
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A207
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A1133
https://exchange.xforce.ibmcloud.com/vulnerabilities/16348
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2004/ms04-025
http://www.us-cert.gov/cas/techalerts/TA04-212A.html
http://www.us-cert.gov/cas/techalerts/TA04-184A.html
http://www.us-cert.gov/cas/techalerts/TA04-163A.html
http://www.kb.cert.org/vuls/id/713878
http://umbrella.name/originalvuln/msie/InsiderPrototype/
http://marc.info/?l=bugtraq&m=108852642021426&w=2
http://marc.info/?l=bugtraq&m=108786396622284&w=2
http://archives.neohapsis.com/archives/fulldisclosure/2004-06/0104.html
http://archives.neohapsis.com/archives/fulldisclosure/2004-06/0031.html