|
COMMAND WebLogic SYSTEMS AFFECTED BEA WebLogic Enterprise 5.1.x, WebLogic Server and Express 4.5.x, 5.1.x PROBLEM Following is based on Foundstone Security Advisory by Saumil Shah and Shreeraj Shah. Two show code vulnerabilities exist with BEA's WebLogic 5.1.0 allowing an attacker to view the source code of any file within the web document root of the web server. Depending on web application and directory structure attacker can access and view unauthorized files. 1. Viewing unparsed pages by forcibly invoking SSIServlet ========================================================= Server Side Includes pages are processed by the SSIServlet in WebLogic. It is registered in the weblogic.properties file as follows: weblogic.httpd.register.*.shtml=weblogic.servlet.ServerSideIncludeServlet It turns out that the wild card (*) registration can itself be used as a handler to invoke the SSIServlet via a URL. Thus, if the file path in the URL is prefixed with /*.shtml/, one can force that file to be processed by SSIServlet. If used against other file types such as .jsp and .jhtml, unparsed jsp and jhtml code can be viewed. 2. Viewing unparsed pages by forcibly invoking FileServlet ========================================================== WebLogic comes pre-configured with the ConsoleHelp servlet being registered to invoke FileServlet, as can be seen from the following lines in the weblogic.properties file: # For Console help. Do not modify. weblogic.httpd.register.ConsoleHelp=weblogic.servlet.FileServlet weblogic.httpd.initArgs.ConsoleHelp=\defaultFilename=/weblogic/admin/help/NoContent.html weblogic.allow.execute.weblogic.servlet.ConsoleHelp=everyone Thus, if the file path in the URL is prefixed with /ConsoleHelp/, it causes WebLogic to invoke FileServlet, which causes pages to be displayed without being parsed or compiled. Proof of concept? 1. Using *.shtml: Prefixing the path to web pages with "/*.shtml/" in the URL causes the file to be displayed since it is processed by SSIServlet. For example if the URL for a file "login.jsp" is: http://site.running.weblogic/login.jsp then accessing http://site.running.weblogic/*.shtml/login.jsp would served by SSIServlet and jsp/jhtml code can be seen in the web browser. 2. Using ConsoleHelp: Prefixing the path to web pages with "/ConsoleHelp/" 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.weblogic/login.jsp then accessing http://site.running.weblogic/ConsoleHelp/login.jsp would cause the unparsed contents of the file to show up in the web browser. SOLUTION Please refer to BEA security advisory BEA00-03.00. From the vendor (as appears in BEA00-03.00): (1) Apply the "Show Code" vulnerability patch available from BEA Technical Support. This patch is available for: - The J-Engine in BEA WebLogic Enterprise 5.1.x - BEA WebLogic Server and Express 5.1.x - BEA WebLogic Server and Express 4.5.x Contact BEA Technical Support at support@bea.com for patch. (2) Once the patch has been applied, review the weblogic.propertiesfile and ensure that the following changes have been made: weblogic.httpd.register.file=weblogic.servlet.FileServlet weblogic.httpd.initArgs.file=defaultFilename=index.html weblogic.httpd.defaultServlet=file should be changed to: weblogic.httpd.register.*.html=weblogic.servlet.FileServlet weblogic.httpd.initArgs.*.html=defaultFilename=index.html weblogic.httpd.defaultServlet=*.html Future Service Packs for BEA WebLogic Server and Express will also contain the patch to address this vulnerability.