I think they're stealing auth tokens, not sure if 2fa would help. It looks like there may be a vulnerability in the markdown editor and being able to insert JavaScript. The JS being able to access your cookies to share them is the second issue.
Yup. Changing your password or 2FA wouldn’t help here, because they’re not actually logging into your account. Rather, they’re simply telling the server that they’re already logged in, using your auth token as proof. You know that little “Keep me logged in” checkbox that everyone clicks when they log in? That stores an auth token on your browser, which is tied to your account.
The next time the browser starts a session on the site, it sends that auth token instead of going through the regular login process. And since the site knows that auth token belongs to your account, it logs you in automatically without needing to go through the regular login process.
So basically, they’re stealing a cookie from your browser, with your name on it. Then they’re able to tell the server that they’re you, by presenting that cookie as proof.
Proper procedure should be to deauthorize any auth tokens when you change your password. But even big sites get lazy about this sometimes, so it may not be the default. If this is the case for Lemmy, even changing your password won’t help because it doesn’t automatically deauth that token.
It's not the "remember me" checkbox.
Unless you are entering your credentials every time you perform an action on a website (click a button, navigate a page, submit a form), your session (or JWT in this case) is stored on your client and is accessible by your client.
So XSS can still extract usable tokens, regardless of the "remember me".
JWTs have an access token (short lived) and a refresh token (long lived).The refresh token allows the client to request a new access token without requiring further credentials (this is usually a stateful action and allows the server to check for banned accounts etc before issuing a new access token. It essentially "debounces" a lot of database activity, and still allows for a lot of authorisation of users).
However the access token is valid until it expires (unless servers run a stateful blocklist of tokens, which is unlikely).
The TTL of an access token defines the attack window.
5 minute tokens are more secure, however result in a lot more database hits due to more token refreshes.
30 minutes is still decent. A lot use 4 hours.
But once an access token is issued, it's valid for its entire lifetime.Maintaining a blocklist of invalidated access tokens (allowing instant user account blocking, instead of having to wait for access tokens to expire) is doable - because the tokens it has to store are short lived the dataset should be small and light.
This can even be done in-memory, with a 5m database poll to update the block list.
However, this becomes difficult to manage over distributed systems.
And it still leaves a 5 minute window.The other way to invalidate JWTs is by rotating the secrets used to create them.
This will mean the server will not trust JWTs created with the old secrets. It's a pretty nuclear option.
However this affects all tokens, so everyone has to reauthenticate.Thank you both for explaining that so clearly :)
Also yikes.
Custom emojis in passwords are now mandatory
please say yes 😭
Weak mindset. I prefer setting my password to 'password' and leaving the rest up to god
1234‽ That’s the combo on my luggage!
🤞
