I belive this is possible via the Magento Connect tool (https://kb.magenting.com/content/5/95/en/upgrade-magento-via-magento-connect.html), HOWEVER just because you can doesn't mean you should. Mabey for small versions updates for small merchants it would work.
However there are a bunch of issues I can think of that could occur and if you do this I think you should be prepared for your store to break and website to stop working.
Some of those issues could be:
Umm. I see granite clouds in the future.
Unless you've done absolutely no customization to Magento, upgrades aren't as easy as you think. And even then, they can have really strange database update problems.
Learn how to run a staging server, do your upgrades on that so you don't suffer economic loss through killing your live e-commerce server. After thorough testing, only then do you attempt upgrading your live site.
The automated update you so desire is in the connect module, it's really easy until you've done it once and had it fail. Being built into the admin panel will not cure the issues that a Magento upgrade can cause.