IIS Server Handling of URLs Using "\", "<", and ">"

• Microsoft Internet Information Server version 1.0

SYMPTOMS

Web clients that send Universal Resource Locator (URL) map requests using the backward slash (\) as a relational specifier can point to any file on the disk. Web clients that send Common Gateway Interface (CGI) requests using either of the angle brackets (< or >) as a redirection specifier can overwrite a file on the disk.

CAUSE

Internet Information Server 1.0 (IIS) did not handle the backward slash (\) in the same way as the forward slash (/); consequently, URL map requests using '\' could be used to specify any file in the hierarchical file system structure on the server.

IIS CGI processing did not disable the use of either of the angle brackets (< or >) as redirection operators; consequently, CGI requests can overwrite existing files by redirecting console output to a filename on the server.

STATUS

Microsoft has confirmed this to be a problem in IIS version 1.0. This problem was corrected in the latest Windows NT 3.51 U.S. Service Pack. For information on obtaining the Service Pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

   S E R V P A C K