Apache Tomcat 4.0.3 for Windows allows remote attackers to obtain the web root path via an HTTP request for a resource that does not exist, such as lpt9, which leaks the information in an error message.
http://www.securityfocus.com/bid/5054
http://www.iss.net/security_center/static/9394.php
http://tomcat.apache.org/security-4.html
http://archives.neohapsis.com/archives/bugtraq/2002-06/0225.html