Description
The Java implementation of AMF3 deserializers used in Flamingo amf-serializer by Exadel, version 2.2.0 derives class instances from java.io.Externalizable rather than the AMF3 specification's recommendation of flash.utils.IExternalizable. A remote attacker with the ability to spoof or control an RMI server connection may be able to send serialized Java objects that execute arbitrary code when deserialized.
Remediation
References
http://www.securityfocus.com/bid/97380
http://www.securityweek.com/flaws-java-amf-libraries-allow-remote-code-execution
https://codewhitesec.blogspot.com/2017/04/amf.html
https://www.kb.cert.org/vuls/id/307983