APPLE-SA-2014-09-29-1 OS X bash Update 1.0
OS X bash Update 1.0 is now available and addresses the following:
OS X bash Update 1.0 may be obtained from the following webpages:
<
http://support.apple.com/kb/DL1767> – OS X Lion
<
http://support.apple.com/kb/DL1768> – OS X Mountain Lion
<
http://support.apple.com/kb/DL1769> – OS X Mavericks
Eve if you don't know the ins and outs of the 'Shellshock' bug, if you've got remote access switched on on your Mac it will be worth applying the patch. If you don't forward any ports to your mac through your router and your Mac isn't in the routers DMZ, you're probably OK but there's always 'better safe than sorry'.
If none of this means anything to you.. sadly, it might be time you learned..