Disable cross domain web security in Firefox

Question

In Firefox, how do I do the equivalent of --disable-web-security in Chrome. This has been posted a lot, but never a true answer. Most are links to add-ons (some

Answer 1

From this answer I've known a CORS Everywhere Firefox extension and it works for me. It creates MITM proxy intercepting headers to disable CORS. You can find the extension at addons.mozilla.org or here.