CVE-2019-12209: High severity yubico pam u2f vulnerability

Published Jun 4, 2019

Updated

Yubico pam-u2f 1.0.7 attempts parsing of the configured authfile (default $HOME/.config/Yubico/u2fkeys) as root (unless openasuser was enabled), and does not properly verify that the path lacks symlinks pointing to other files on the system owned by root. If the debug option is enabled in the PAM configuration, part of the file contents of a symlink target will be logged, possibly revealing sensitive information.

Affected Software

1 affected component

Yubico pam-u2f=1.0.7

Remediation

Patch Available

https://github.com/Yubico/pam-u2f/commit/7db3386fcdb454e33a3ea30dcfb8e8960d4c3aa3

Event History

Jun 4, 2019

CVE Published

via MITRE·08:26 PM

Data Sourced

via MITRE·08:26 PM

Description

Frequently Asked Questions

What is the severity of CVE-2019-12209?

The severity of CVE-2019-12209 is high.

How does Yubico pam-u2f 1.0.7 handle the configured authfile?

Yubico pam-u2f 1.0.7 attempts parsing of the configured authfile (default $HOME/.config/Yubico/u2f_keys) as root (unless openasuser was enabled).

What does Yubico pam-u2f 1.0.7 fail to verify?

Yubico pam-u2f 1.0.7 fails to properly verify that the path lacks symlinks pointing to other files on the system owned by root.

Can the vulnerability be exploited if the debug option is enabled in the PAM configuration?

Yes, the vulnerability can be exploited if the debug option is enabled in the PAM configuration.

How can I fix CVE-2019-12209?

Update Yubico pam-u2f to version 1.1.0 or later.