A detailed analysis of the reference: https://codewhitesec.blogspot.kr/2017/04/amf.html
Some Java implementations of AMF3 deserializers allow the external entity references (XXEs) from XML documents embedded within AMF3 messages. If the XML parsing is handled incorrectly it could potentially expose sensitive data on the server, denial of service, or server side request forgery.
Products using these libraries may also be impacted.
More information is provided in the researcher's advisory.