Why is 0.0.0.0:1500 added to inbound rules in the Staging Area? - AWS Elastic Disaster Recovery

Why is 0.0.0.0:1500 added to inbound rules in the Staging Area?

AWS Elastic Disaster Recovery uses TCP Port 1500 for replication between the source agents and the replication server. The connection is open for all IPs and can be managed by ACLs or networks controls to limit inbound IPs.