SAML https://seanmelia.files.wordpress.com/2016/01/out-of-band-xml-external-entity-injection-via-saml-redacted.pdf https://docs.google.com/presentation/d/1ngp3Mq8y2h2xwGKqkOhI1ePUQxvXTNO1Xhs1kaBJmqU/edit