Apple has released a security patch for the recent POODLE and Shellshock security holes.  These updates can be found on Macs in “Software Update”.

PLEASE NOTE:  The Software Updates appear BELOW the OS X Yosemite upgrade (with nice color photo of cloud shrouded El Capitan in Yosemite National Park).  If you rely on your Mac to do your work, DO NOT DO the free OS X Yosemite upgrade. Please wait until the bugs have been worked out.

So DO the Software Update but NOT the Yosemite Upgrade.