TCAT-AS-000520 - DefaultServlet directory listings parameter must be disabled.
The DefaultServlet serves static resources as well as directory listings. It is declared globally in $CATALINA_BASE/conf/web.xml and by default is configured with the directory 'listings' parameter set to disabled. If no welcome file is present and the 'listings' setting is enabled, a directory listing is shown. Directory listings must be disabled.
From the Tomcat server as a privileged user: Edit the $CATALINA_BASE/conf/web.xml file. Examine the <init-param> elements within the <Servletclass> element, if the 'listings' <param-value>element is 'true' change the 'listings' <param-value> to read 'false'. sudo systemctl restart tomcat sudo systemctl daemon-reload