** Inge Henriksen Security Advisory - Full Disclosure Proof of Concept at http://ingehenriksen.blogspot.com/ ** Advisory Name: Microsoft IIS Remote Denial of Service (DoS) .DLL Url exploit Release Date: 16. Desember 2005 Vulnerable: Microsoft&#174; Internet Information Server&#174; V5.1 Not vulnerable: Microsoft&#174; Internet Information Server&#174; V5.0 Microsoft&#174; Internet Information Server&#174; V6.0 Severity: High Discovered by: Inge Henriksen (inge.henriksen (at) booleansoft (dot) com [email concealed]) http://ingehenriksen.blogspot.com/ Vendor Status: Notified 28. January 2005. No fix will be released until Microsoft&#174; Windows&#174; XP Service Pack 3 (Rumored due late 2006). Description: I have found that by doing a malformed anonymous HTTP request one can remotely crash the IIS service process, inetinfo.exe, using just a simple tool like a web browser. The vulnerablity is only present in folders with Execute Permissions set to Scripts & Executables, examples of vulnerable virtual folders would be "<webroot>/_vti_bin" and the like. Suggested solution: Block all incoming URL's containing "~0", "~1", "~2", "~3", "~4", "~5", "~6", "~7", "~8", or "~9" (Ignore quotes). Full Disclosure Proof of Concept at http://ingehenriksen.blogspot.com/