the impact varied by customer. in Discord's case, the auth token is stored in local storage and their docs is hosted on the primary domain; they were susceptible to a full account takeover. X's docs are on a different subdomain but we found a CSRF attack that could facilitate a full account takeover. most companies were significantly affected in one way or another.

Interesting. I agree with the other commenter about the post should've included how an account takeover was possible.

You mention one method being a cookie sent to an attacker-controlled domain, but that in itself is a vulnerability given it being incorrectly scoped (missing HTTPOnly & SameSite atleast).

> the auth token is stored in local storage

Has anyone reported this (rhetorical question)? What in the world could be the justification for this?

In my opinion, any full account takeovers due to XSS is a vulnerability, even ignoring XSS. Changing email/password/phone should require verification back to one of those methods. Or at least input of the previous password.

And to my earlier point, none of that is in the writeup here to support the enormous claims made in framing the finding. This is good work, and congratulations on the bounty. I hope you have a long career in security ahead. Obviously you communicated your findings to Discord clearly enough for them to understand the impact. I look forward to reading more research from you all in the future and I hope the technical details will accompany it.