Microsoft Internet Explorer 5.01 SP4, 6, 6 SP1, 7, and 8 does not prevent rendering of non-HTML local files as HTML documents, which allows remote attackers to bypass intended access restrictions and read arbitrary files via vectors involving the product's use of text/html as the default content type for files that are encountered after a redirection, aka the URLMON sniffing vulnerability, a variant of CVE-2009-1140 and related to CVE-2008-1448.