Secunia

Secunia Research has discovered a vulnerability in Internet Explorer, which can be exploited by malicious web sites to spoof dialog boxes.

The problem is that JavaScript dialog boxes do not display or include their origin, which allows a new window to open e.g. a prompt dialog box, which appears to be from a trusted site.

Successful exploitation normally requires that a user is tricked into opening a link from a malicious web site to a trusted web site.

Secunia has constructed a test, which can be used to check if your browser is affected by this issue:
http://secunia.com/multiple_browsers_dialog_origin_vulnerability_test/

The vulnerability has been confirmed in a fully updated version 6.0. Prior versions may also be affected.

Solution
Do not browse untrusted web sites while browsing trusted sites.

Provided and/or discovered by
Jakob Balle, Secunia Research

Changelog
Further details available in Customer Area

Original Advisory
Secunia Research:
http://secunia.com/secunia_research/2005-9/

Microsoft:
http://www.microsoft.com/technet/security/advisory/902333.mspx

Deep Links
Links available in Customer Area