CVE-2015-8559
The knife bootstrap command in chef Infra client before version 15.4.45 leaks the validator.pem private RSA key to /var/log/messages.
Date published : 2017-09-21
https://github.com/chef/chef/issues/3871
https://discourse.chef.io/t/chef-infra-client-15-4-45-released/16081