Current zero-day hype:
SCARY as hell, as always. Everywhere. If you're using even a just slightly older browser version, just a few days old, you're already as good as ***DEAD***! Boah...
But also as always (99%), this only can hit if JAVASCRIPT is allowed?
And additionally, this even requires a special JS feature "JIT" to be allowed too? And the only purpose of this is to speed up scripts, in exchange for much higher dangers?
At least if I get it right and this article is about that current hype?
https://nakedsecurity.sophos.com/2020/01/09/browser-zero-day-update-your-firefox-right-now/
If that's all, have no worry... My *really* old browser version allows blocking JIT since years (and JS by default off anyway, or freezing for lack of RAM):
pref("javascript.options.jit.chrome", false);
pref("javascript.options.jit.content", false);
pref("javascript.options.jit.__INFO", "INFO: for better JS speed, but highly dangerous, zero-day vulnerable");
But no idea if those prefs are still valid for current modern browsers.
And also added today to my tweaked Default prefs file, acc to above article, just in case I'll some day install Tor:
pref("javascript.options.ion", false);
pref("javascript.options.ion__INFO", "INFO: JS-JIT in Tor, for better JS-speed but highly dangerous, zero-day vulnerable");