It's currently possible to manage special groups from the UCP if you are the group leader. If someone is set as the leader of the administrators group, this feature allows to add additional admins without access to the ACP.

It's currently already not possible to edit group descriptions for special groups via the UCP. To keep things simple we should also add this limitation to the UCP group management for special groups. Special groups will have to be managed from the ACP requiring an additional security check.

The side effect of this change will be that leader of the Global Moderators group will no longer be able to add or remove team members via the UCP. This could be solved by creating a different moderator group.