[makomk]

The exploit is targeted at the version of Firefox in the Tor Browser Bundle on Windows, which means most Tor users are vulnerable. While you can use a different browser the Tor developers have generally recommended that people don't; it's hard to lock down browsers against information leaks, and the fact that someone's using an unusual browser helps an attacker track them.

[mbrubeck]

Actually it turns out to exploit an vulnerability that was already fixed in both Firefox and Firefox ESR:

https://blog.mozilla.org/security/2013/08/04/investigating-s...

The fix was included in a Tor Browser Bundle update on June 26, 2013:

https://blog.torproject.org/blog/new-tor-browser-bundles-and...