The Spring AMQP Message object, in its toString() method, will deserialize a body for a message with content type application/x-java-serialized-object. Classes in the java.lang and java.util packages are trusted.

It is possible to construct a malicious java.util.Dictionary object that can cause 100% CPU usage in the application if the toString() method is called.

This requires the attacker to have privileges to directly publish messages with such a body to the RabbitMQ server.

• Spring AMQP
  • 2.2.0 - 2.2.18
  • 2.3.0 - 2.3.10

Do not allow untrustworthy actors to publish arbitrary data to RabbitMQ. Users of affected versions should apply the following mitigation. 2.3.x users should upgrade to 2.3.11. 2.2.x users should upgrade to 2.2.19. No other steps are necessary. Releases that have fixed this issue include:

• Spring AMQP
  • 2.3.11
  • 2.2.19

This issue was identified and responsibly reported by r00t4dm Cloud-Penetrating Arrow Lab of Meituan Corp Information Security Department.