[4075] in bugtraq
! [ADVISORY] Major Security Hole in MS ASP
daemon@ATHENA.MIT.EDU (Mark Joseph Edwards)
Thu Feb 20 13:22:27 1997
Date: Thu, 20 Feb 1997 11:39:01 -0600
Reply-To: Mark Joseph Edwards <mark@NTSHOP.NET>
From: Mark Joseph Edwards <mark@NTSHOP.NET>
To: BUGTRAQ@netspace.org
MICROSOFT IIS AND ACTIVE SERVER ADVISORY
Security Hole in ASP Discovered in Microsoft ASP
February 20, 1997
DESCRIPTION
A serious security hole was found in Microsoft's Active Server Pages (ASP) by Juan T. Llibre <j.llibre@codetel.net.do>. This hole allows Web clients to download unprocessed ASP files potentially exposing user ids and passwords. ASP files are the common file type used by Microsoft's IIS and Active Server to perform server-side processing.
HOW IT WORKS
To download an unprocessed ASP file, simply append a period to the asp URL. For example: http://www.domain1.com/default.asp becomes http://www.domain1.com/default.asp. With the period appendage, Internet Information Server (IIS) will send the unprocessed ASP file to the Web client, wherein the source to the file can be examined at will. If the source includes any security parameter designed to allow access to other system processes, such as an SQL database, they will be revealed.
DEFENSE
There are two known ways to stop this behavior:
1.Turn read permissions off of the ASP directory in the Internet Service Manager. This may not be a practical solution since many sites mix ASP and HTML files. If your site mixes these files together in the same directories, you may want to segregate them immediately. Now and in the future, treat your ASP files like any other Web based executable, and keep them in separate directories wherein permissions can be adjusted accordingly.
2.Download this filter written by Christoph Wille Christoph.Wille@unileoben.ac.at which can be located at http://www.ntshop.net/security/tools/sechole.zip or from http://www.genusa.com/asp/patch/sechole.zip
END OF ADVISORY
