An issue was discovered in Hyland org.alfresco:alfresco-content-services through 6.2.2.18 and org.alfresco:alfresco-transform-services through 1.3. A crafted HTML file, once uploaded, could trigger an unexpected request by the transformation engine. The response to the request is not available to the attacker, i.e., this is blind SSRF.
https://www.themissinglink.com.au/
https://github.com/Alfresco/acs-packaging/blob/master/DISCLOSURES.md