Webmin 0.92, when installed from an RPM, creates /var/webmin with insecure permissions (world readable), which could allow local users to read the root user's cookie-based authentication credentials and possibly hijack the root user's session using the credentials.
https://exchange.xforce.ibmcloud.com/vulnerabilities/8595
https://euvd.enisa.europa.eu/vulnerability/EUVD-2002-1653
http://www.webmin.com/changes.html