One of the backup criteria for determining a file type is the result of the MIME sniff. By examining (or sniffing) a file, ...

"One of the backup criteria for determining a file type is the result of the MIME sniff. By examining (or sniffing) a file, Internet Explorer can recognize the bit signatures of certain types of files. In Windows XP Service Pack 2, Internet Explorer MIME sniffing will never promote a file of one type to a more dangerous file type. For example, files that are received as plain text but that include HTML code will not be promoted to the HTML type, which could contain malicious code.

In the absence of other file type information, the MIME sniff might be the only information that determines how to handle a given file download. If, for instance, Internet Explorer upgrades a text file to an HTML file, the file might execute code from the browser and possibly elevate the file's security privilege.

Settings note: this feature can be turned off by zone in IE security zones settings."
English
English (United States)
日本語
Japanese