ENFORCE_ENCODING_IN_GET_WRITER must be set to true.

Some clients try to guess the character encoding of text media when the mandated default of ISO-8859-1 should be used. Some browsers will interpret as UTF-7 when the characters are safe for ISO-8859-1. This can create the potential for a XSS attack. To defend against this, enforce_encoding_in_get_writer must be set to true.

From the Tomcat server as a privileged user, run the following command:

sudo grep -i  enforce_encoding /etc/systemd/system/tomcat.service 

If there are no results, or if the org.apache.catalina.connector.Response.ENFORCE_ENCODING_IN_GET_WRITER is not ="true", this is a finding.

From the Tomcat server as a privileged user:

Edit the /etc/systemd/system/tomcat.service file, and either add or edit the org.apache.catalina.connector.Response.ENFORCE_ENCODING_IN_GET_WRITER setting.

Set the org.apache.catalina.connector.Response.ENFORCE_ENCODING_IN_GET_WRITER=true

EXAMPLE: Environment='CATALINA_OPTS -Dorg.apache.catalina.connector.Response.ENFORCE_ENCODING_IN_GET_WRITER=true'

Restart the Tomcat server: sudo systemctl restart tomcat sudo systemctl daemon-reload