this post was submitted on 17 Jan 2024
5 points (66.7% liked)

netsec

1313 readers
1 users here now

Technical news and discussion of information security.

Rules:

  1. Be excellent to each other
  2. Keep it on topic
  3. Absolutely no PII or doxing
  4. No disclosure posts

founded 2 years ago
MODERATORS
t8r@lemmy.world
5
As if you needed another reason not to ever use SSO to your Google account for anything (mbin.grits.dev)
submitted 2 years ago by mozz@mbin.grits.dev to c/netsec@lemmy.world
11 comments fedilink hide all child comments
 

For some reason this only just now occurred to me: What's to stop some web site from carefully crafting an imitation of the Google "you need to sign in again" UI, storing your Google password, and storing from the other side the auth cookie from Google, so that it can then poke around through 100% of your Google content including any other site you've signed into with the same SSO login?

This is such a fundamental flaw in the whole concept that it's obviously occurred to people and they've had time to come up with something to prevent it, but I can't see how you could prevent it. Have I missed something? You might have a non-Google URL in the address bar during the faked sign-in, or you could use varying degrees of deception to attempt to make the address bar look legit, but I'd honestly be surprised if more than 20% of people even check the address bar every time they sign in to SSO. I don't.

So what's to make this not work?

you are viewing a single comment's thread
view the rest of the comments
[–] mozz@mbin.grits.dev 2 points 2 years ago
  1. Google Oauth currently doesn't do that
  2. We're doing man-in-the-middle under my proposed scenario anyway (we have to, to defeat 2FA and get a real Oauth token.) It's trivial to show the user the Google-provided image of the user's choosing.