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Gentoo Linux Security Advisory                           GLSA 202208-11
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                                           https://security.gentoo.org/
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 Severity: Low
    Title: Yubico pam-u2f: Local PIN Bypass vulnerability
     Date: August 10, 2022
     Bugs: #792270
       ID: 202208-11

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Synopsis
=======
A vulnerability has been discovered in pam-u2f which could allow a local
attacker to bypass PIN entry.

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

Affected packages
================
    -------------------------------------------------------------------
     Package              /     Vulnerable     /            Unaffected
    -------------------------------------------------------------------
  1  sys-auth/pam_u2f           < 1.1.1                      >= 1.1.1

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"

References
=========
[ 1 ] CVE-2021-31924
      https://nvd.nist.gov/vuln/detail/CVE-2021-31924
[ 2 ] YSA-2021-03

Availability
===========
This GLSA and any updates to it are available for viewing at
the Gentoo Security Website:

 https://security.gentoo.org/glsa/202208-11

Concerns?
========
Security is a primary focus of Gentoo Linux and ensuring the
confidentiality and security of our users' machines is of utmost
importance to us. Any security concerns should be addressed to
security@gentoo.org or alternatively, you may file a bug at
https://bugs.gentoo.org.

License
======
Copyright 2022 Gentoo Foundation, Inc; referenced text
belongs to its owner(s).

The contents of this document are licensed under the
Creative Commons - Attribution / Share Alike license.

https://creativecommons.org/licenses/by-sa/2.5