It appears that malformed HTTP requests to IIS versions 5.0, 5.1, and 6.0 allow for a remote crash of the service.
6d185deb53682ef93b3fa88fdec275761c1a6503427ac16a9c6c4de27066e357
** 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® Internet Information Server® V5.1
Not vulnerable:
Microsoft® Internet Information Server® V5.0
Microsoft® Internet Information Server® V6.0
Severity:
High
Discovered by:
Inge Henriksen (inge.henriksen@booleansoft.com) http://ingehenriksen.blogspot.com/
Vendor Status:
Notified 28. January 2005. No fix will be released until Microsoft® Windows® 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/