The default configuration in Apache Cassandra 1.2.0 through 1.2.19, 2.0.0 through 2.0.13, and 2.1.0 through 2.1.3 binds an unauthenticated JMX/RMI interface to all network interfaces, which allows remote attackers to execute arbitrary Java code via an RMI request.
Apache Cassandra versions 2.1.0 to 2.1.22, 2.2.0 to 2.2.19, 3.0.0 to 3.0.23, and 3.11.0 to 3.11.9, when using 'dc' or 'rack' internodeencryption setting, allows both encrypted and unencrypted internode connections. A misconfigured node or a malicious user can use the unencrypted connection despite not being in the same rack or dc, and bypass mutual TLS requirement.