←back to thread

I read the federal government’s Zero-Trust Memo so you don’t have to

(www.bastionzero.com)
656 points EthanHeilman | 1 comments | 27 Jan 22 15:06 UTC | HN request time: 0.286s | source
Show context
staticassertion ◴[27 Jan 22 15:56 UTC] No.30102061[source]▶
This is pretty incredible. These aren't just good practices, they're the fairly bleeding edge best practices.

1. No more SMS and TOTP. FIDO2 tokens only.

2. No more unencrypted network traffic - including DNS, which is such a recent development and they're mandating it. Incredible.

3. Context aware authorization. So not just "can this user access this?" but attestation about device state! That's extremely cutting edge - almost no one does that today.

My hope is that this makes things more accessible. We do all of this today at my company, except where we can't - for example, a lot of our vendors don't offer FIDO2 2FA or webauthn, so we're stuck with TOTP.

replies(15): >>30103088 #>>30103131 #>>30103846 #>>30104022 #>>30104121 #>>30104716 #>>30104840 #>>30105344 #>>30106941 #>>30107798 #>>30108481 #>>30108567 #>>30108916 #>>30111757 #>>30112413 #
pitaj ◴[27 Jan 22 18:17 UTC] No.30104022[source]▶
What's wrong with TOTP?
replies(4): >>30104104 #>>30104125 #>>30104610 #>>30114646 #
1. yonixw ◴[28 Jan 22 14:00 UTC] No.30114646[source]▶
MITM phishing attacks (also called real time phishing).

If someone just put a fake domain that proxies everything between you and the server (with fake domain with HTTPS... which he social engineered you to get on)

Looks like FIDO2 2FA only sign the challenge response against the server certificate available locally (= the phishing domain) so just passing it to the original server will fail. Also, the attacker can't just re-sign the challenge response after you, because the challenge was sent from the original server already encrypted with the public key of the user (stored from the registration phase). So only the registered user can see the challenge and respond to it.

This leaves only 2 options to do a phishing attack: 1) Get a valid certificate for the original domain [1] 2) force downgrade the user to old TOTP [2]

[1] https://security.stackexchange.com/q/157756/69837

[2] https://eprint.iacr.org/2020/1298.pdf