Yubico pam-u2f: Local PIN Bypass vulnerability

Background

Yubico pam-u2f is a PAM module for FIDO2 and U2F keys.

Description

A logic issue in Yubico pam-u2f could result in the bypass of a PIN entry requirement when authenticating with FIDO2.

Impact

An attacker with local access to certain applications using pam-u2f for authentication could incorrectly successfully authenticate without entering the authentication PIN.

Workaround

There is no known workaround at this time.

Resolution

All Yubico pam-u2f users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=sys-auth/pam_u2f-1.1.1"