Calendar Overlay in SharePoint 2013

I am able to overlay the exchange calendar of each user and display it, when the user logs into SharePoint 2013. 

But the details of events show up as busy and not the actual subject.

So I changed the calendar option in outlook. Change the permission for default account to read full details.

(Outlook->Tools->Options->Calendar Options->Free Busy Options->set read permission to full details for default account)

Now with the new setting everything works fine.

The problem is now, every other user can see the events of any user. So user x can view what the CEO of a company is planning. I want to avoid this. 

So is there a way to force SharePoint to access exchange using the current user permissions instead of the default one ?

Thank you,