Overview

A remote attacker can bypass WSFed authentication on a website using passport-wsfed-saml2. A successful attack requires that the attacker is in possession of an arbitrary IDP signed WSFed assertion. Depending on the IDP used, fully unauthenticated attacks (e.g without access to a valid user) might also be feasible if generation of a signed message can be triggered.

Am I affected?

You are affected if you are using WSFed protocol with the passport-wsfed-saml2 library versions < 4.6.3.
SAML2 protocol is not affected.

How do I fix it?

Upgrade the library to version 4.6.3.

Will the fix impact my users?

No, the fix will not impact your users.