Secunia

Description
http-equiv has identified a vulnerability in Internet Explorer, allowing malicious web sites to spoof the file extension of downloadable files.

The problem is that Internet Explorer can be tricked into opening a file, with a different application than indicated by the file extension. This can be done by embedding a CLSID in the file name. This could be exploited to trick users into opening "trusted" file types which are in fact malicious files.

Secunia has created an online test:
http://secunia.com/Internet_Explorer_File_Download_Extension_Spoofing_Test/

This has been reported to affect Microsoft Internet Explorer 6.

NOTE: Prior versions may also be affected.

Solution
The vulnerability has been fixed silently in some cumulative security update.

Provided and/or discovered by
http-equiv

Changelog
Further details available in Customer Area

Deep Links
Links available in Customer Area