Image credit: Andy Fitzsimon
WordPress.org states 4.0.1 is a critical security release for all previous versions. All sites are strongly encouraged to update. If you have automatic background updates turned on, your site will automatically be updated in the next few hours. If you do not have automatic updates turned on, Download WordPress 4.0.1 or login to your WP Backend and go to Dashboard ? Updates and simply click “Update Now”.
WordPress versions 3.9.2 and earlier are affected by a critical cross-site scripting vulnerability, which could enable anonymous users to compromise a site. This was reported by Jouko Pynnonen. This issue does not affect version 4.0, but version 4.0.1 does address these eight security issues:
- Three cross-site scripting issues that a contributor or author could use to compromise a site. Discovered by Jon Cave, Robert Chapin, and John Blackbournof the WordPress security team.
- A cross-site request forgery that could be used to trick a user into changing their password.
- An issue that could lead to a denial of service when passwords are checked. Reported by Javier Nieto Arevalo and Andres Rojas Guerrero.
- Additional protections for server-side request forgery attacks when WordPress makes HTTP requests. Reported by Ben Bidner (vortfu).
- An extremely unlikely hash collision could allow a user’s account to be compromised, that also required that they haven’t logged in since 2008 (I wish I were kidding). Reported by David Anderson.
- WordPress now invalidates the links in a password reset email if the user remembers their password, logs in, and changes their email address. Reported separately by Momen Bassel, Tanoy Bose, and Bojan Slavkovi?.