TCAT-AS-000020 - Secured connectors must be configured to use strong encryption ciphers.
Information
The Tomcat <Connector> element controls the TLS protocol and the associated ciphers used. If a strong cipher is not selected, an attacker may be able to circumvent encryption protections that are configured for the connector. Strong ciphers must be employed when configuring a secured connector. The configuration attribute and its values depend on what HTTPS implementation the user is utilizing. The user may be utilizing either Java-based implementation aka JSSE - with BIO and NIO connectors, or OpenSSL-based implementation - with APR connector. TLSv1.2 ciphers are configured via the server.xml file on a per connector basis. For a list of approved ciphers, refer to NIST SP 800-52 section 3.3.1.1. NOTE: Nessus has provided the target output to assist in reviewing the benchmark to ensure target compliance.
Solution
As a privileged user on the Tomcat server, edit the $CATALINA_BASE/conf/server.xml and modify the <Connector/> element. Add the SSLEnabledProtocols='TLSv1.2' setting to the connector or modify the existing setting. Set SSLEnabledProtocols='TLSv1.2'. Save the server.xml file and restart Tomcat: sudo systemctl restart tomcat sudo systemctl reload-daemon