Hazelcast Management Center through 6.0 allows remote code execution via a JndiLoginModule user.provider.url in a hazelcast-client XML document (aka a client configuration file), which can be uploaded at the /cluster-connections URI.
The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.