Microsoft FrontPage Server Extensions MS-DOS Device Name Denial Of Service Vulnerability
It is possible to remotely crash a system running Microsoft FrontPage Server Extensions by conducting a URL request for a MS-DOS device through shtml.exe. For example, the following URL requests will crash FrontPage Server Extensions:
http://target/_vti_bin/shtml.exe/comX.htm (X being one of 1, 2 ,3, or 4; the device must exist on the target machine)
The device name must have an appended extension in order for the exploit to work. In addition to the HTM extension, ASP will work as well. Restarting IIS or rebooting the system is required in order to regain normal functionality.
Testing has shown that it may require a constant stream of these requests in order to render the server ineffective.