Sensitive information disclosure vulnerability resulting from a lack of certificate validation during the File-Based Backup and Restore operations of VMware vCenter Server Appliance (6.7 before 6.7u3a and 6.5 before 6.5u3d) may allow a malicious actor to intercept sensitive data in transit over FTPS and HTTPS. A malicious actor with man-in-the-middle positioning between vCenter Server Appliance and a backup target may be able to intercept sensitive data in transit during File-Based Backup and Restore operations.
https://www.vmware.com/security/advisories/VMSA-2019-0018.html