COMMAND
WebSphere
SYSTEMS AFFECTED
IBM WebSphere Application Server 3.0.2
PROBLEM
Following is based on Foundstone Security Advisory by Shreeraj
Shah and Saumil Shah. A show code vulnerability exists with
IBM's Websphere allowing an attacker to view the source code of
any file within the web document root of the web server.
IBM WebSphere uses Java Servlets to handle parsing of various
types of pages (for example, HTML, JSP, JHTML, etc). In
addition to different servlets for handling different kinds of
pages, WebSphere also has a default servlet which is called
upon if a requested file does not have a registered handler.
It is possible to force the default servlet to be invoked if the
file path in the URL is prefixed with "/servlet/file/", which
causes pages to be displayed without being parsed or compiled.
It is easy to verify this vulnerability for a given system.
Prefixing the path to web pages with "/servlet/file/" in the URL
causes the file to be displayed without being parsed or compiled.
For example if the URL for a file "login.jsp" is:
http://site.running.websphere/login.jsp
then accessing
http://site.running.websphere/servlet/file/login.jsp
would cause the unparsed contents of the file to show up in the
web browser.
SOLUTION
Remove the InvokerServlet from the webapplication. Fix is APAR
PQ39857 that will be available soon at the site:
http://www-4.ibm.com/software/webservers/appserv/efix.html