The Cloud HSM initialization process creates a new Security Group as part of its install process. This Security Group needs to be added to the EJBCA instance for the two to communicate. 

To assign the security group to the EJBCA instance, do the following:

  1. Select your EJBCA Enterprise Instance (or right click on it) and select: Networking > Change Security Groups.

  2. You will see a new security group that was generated from the CloudHSM install process. Select it and click Assign Security Group.