Microsoft Internet Explorer MIME Type File Extension Spoofing Vulnerability
Microsoft Internet Explorer uses the Content-Type and Content- Disposition HTML header fields to determine the file type of non- HTML files referenced by a website. These two content headers make up the MIME type of the field.
It is possible to insert information into the Content-Type and Content-Disposition fields that would tell Internet Explorer that a file being downloaded is of a different type than it actually is. This would not cause the file to be executed automatically, but could trick a vulnerable user into believing that they are downloading a text file instead of an executable file.
This vulnerablility was originally believed to be the same as the one reported in Bugtraq ID 3597, but was later found to be a different method of achieving the same goal.
Exploit: There is no exploit code.
Solution: Microsoft has released a patch to address this issue:
Microsoft Internet Explorer 5.0.1SP2:
Microsoft Patch q316059_IE 5.01
Microsoft Internet Explorer 5.5SP2:
Microsoft Patch q316059_IE 5.5SP2
Microsoft Internet Explorer 5.5SP1:
Microsoft Patch q316059_IE 5.5SP1
Microsoft Internet Explorer 6.0:
Microsoft Patch q316059_IE6