In spring AMQP versions 1.0.0 to 2.4.16 and 3.0.0 to 3.0.9 , allowed list patterns for deserializable class names were added to Spring AMQP, allowing users to lock down deserialization of data in messages from untrusted sources; however by default, when no allowed list was provided, all classes could be deserialized. Specifically, an application is vulnerable if * the SimpleMessageConverter or SerializerMessageConverter is used * the user does not configure allowed list patterns * untrusted message originators gain permissions to write messages to the RabbitMQ broker to send malicious content