In Couchbase Server 5.0.0, when an invalid Remote Cluster Certificate was entered as part of the reference creation, XDCR did not parse and check the certificate signature. It then accepted the invalid certificate and attempted to use it to establish future connections to the remote cluster. This has been fixed in version 5.5.0. XDCR now checks the validity of the certificate thoroughly and prevents a remote cluster reference from being created with an invalid certificate.