A 6 year old vulnerability has been discovered in multiple browsers, allowing malicious people to spoof the content of websites.

The problem is that the browsers don't check if a target frame belongs to a website containing a malicious link, which therefore doesn't prevent one browser window from loading content in a named frame in another window.

Successful exploitation allows a malicious website to load arbitrary content in an arbitrary frame in another browser window owned by e.g. a trusted 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_frame_injection_vulnerability_test/

The vulnerability has been confirmed in the following browsers:
* Opera 7.51 for Windows
* Opera 7.50 for Linux
* Mozilla 1.6 for Windows
* Mozilla 1.6 for Linux
* Mozilla Firebird 0.7 for Linux
* Mozilla Firefox 0.8 for Windows
* Netscape 7.1 for Windows
* Internet Explorer for Mac 5.2.3
* Safari 1.2.2
* Konqueror 3.1-15redhat

Other versions may also be affected.

The vulnerability also affects Internet Explorer:
SA11966

Solution
Do not browse untrusted sites while browsing trusted sites.
Further details available to Secunia VIM customers

Provided and/or discovered by
Reported in Mozilla browser by:
Gary McKay

Changelog
Further details available to Secunia VIM customers

Original Advisory
KDE:
http://www.kde.org/info/security/advisory-20040811-3.txt

Other references
Further details available to Secunia VIM customers

Deep Links
Links available to Secunia VIM customers