Pin Bypass in Passwordless WebAuthn on Microsoft.com and Nextcloud

Posted by sufficient on Wednesday August 12, 2020 @09:28AM
from the hwsecurity.dev dept.

https://hwsecurity.dev/2020/08/webauthn-pin-bypass/

( 3 comments | 7 points | on HN )

Re:Pin Bypass in Passwordless WebAuthn on Microsoft.com and ... by leif2 on Wednesday August 12, 2020 @11:20AM (#24132921)

Looks like Microsoft doesn't understand the specification that they wrote down themselves: It is a bug if an attacker can take over my entire Microsoft account via NFC. I wonder if Microsoft can make amends for any damage it causes. Credit card companies can do this and that's why some NFC payments are only 1FA.

[ Parent | on HN ]

Re:Pin Bypass in Passwordless WebAuthn on Microsoft.com and ... by serjd on Wednesday August 12, 2020 @10:05AM (#24132170)

> We reported the issue to Microsoft. They did not consider it a vulnerability, but fixed it

Seems like Microsoft doesn't like to pay for a bug bounty

[ Parent | on HN ]

Re:Pin Bypass in Passwordless WebAuthn on Microsoft.com and ... by sufficient on Wednesday August 12, 2020 @11:20AM (#24132918)

I agree that it's weird that they fixed it and didn't consider it a security issue.

For the user it looked like it would provide two-factor authentication since the PIN is requested, while in reality it's not verified. Thus, they only provided one-factor security.

[ Parent | on HN ]