CVE-2009-4444 Information

Description

Microsoft Internet Information Services (IIS) 5.x and 6.x uses only the portion of a filename before a ; (semicolon) character to determine the file extension which allows remote attackers to bypass intended extension restrictions of third-party upload applications via a filename with a (1) .asp (2) .cer or (3) .asa first extension followed by a semicolon and a safe extension as demonstrated by the use of asp.dll to handle a .asp;.jpg file.

Reference

http://blogs.technet.com/msrc/archive/2009/12/27/new-reports-of-a-vulnerability-in-iis.aspx http://secunia.com/advisories/37831 http://securitytracker.com/id?1023387 http://soroush.secproject.com/downloadable/iis-semicolon-report.pdf http://www.securityfocus.com/bid/37460 http://www.vupen.com/english/advisories/2009/3634