I tested Safari at this site:
I got this message, saying I was safe:
Here's my Safari version:
I tried clicking "force the test to run anyway" but it just freezes forever, even though JavaScript is enabled.
So I ran the old version of the test, with this result:
So I checked for updates. The only OS update is for iTunes and Thunderbolt, which seem unrelated to this issue, but I put them on anyway.
That seemed to make no difference to the OS X version, as expected.
Now Safari says I'm safe, and when I force the test to run anyway, it works and says I'm safe. The old version of the page also says I'm safe.
Here's another test--if this page loads, your browser is vulnerable:
https://www.imperialviolet.org:1266/
I get this page, which indicates that I am safe.
Here's another test page:
https://www.ssllabs.com/ssltest/viewMyClient.html
I updated to Mavericks:
And mow I am vulnerable!