Applications that configure their broker connection via RabbitConnectionFactoryBean.setUri("amqps://...") without also calling setUseSSL(true) get TLS encryption with no certificate validation and no hostname verification.
Affected versions:
Spring AMQP 4.0.0 through 4.0.3; 3.2.0 through 3.2.10; 3.1.0 through 3.1.15; 2.4.0 through 2.4.17.