Apple seem to have abandoned their prior operating systems. Having identified and made public some security issues in Mountain Lion they have not made any patches available. This means every hacker in the Mac universe will be trying to break in to any residual Mountain Lion dens. What to do. Upgrade to OS X Mavericks.
On the good side its free, on the down side it’s not yet tried and tested. But, for the moment at least, it’s vulnerabilities are not obvious.
I updated this morning. It’s a lengthy business and initially nothing at all seemed to happen, patience required. Other than the slowness it was quite painless and Firefox is still working for me.
One tip, there comes a moment when you are confronted with a request for your Apple ID and password. The only program available at that moment is the App Store, you can’t get at Keychain, your email or that file where you stupidly recorded all your passwords so that the hacker could find them. So … sort that out before you begin.