[CentOS] what percent of time are there unpatched exploits against default config?

> password"?  That's what I'm talking about -- how often does this sort of
> thing happen, where you need to be subscribed to be a security mailing list
> in order to know what workaround to make to stay safe, as opposed to simply
> running yum-updatesd to install latest patches automatically.

Happens all the time! Count on it! If running any server available to 
the public there is no "set and forget" if you're responsible for that 
server you best stay informed/subscribed and ready to take action be it 
a work around, update or whatever.