출처 : https://wordpress.org/news/2015/08/wordpress-4-2-4-security-and-maintenance-release/
WordPress 4.2.4 is now available. This is a security release for all previous versions and we strongly encourage you to update your sites immediately.
This release addresses six issues, including three cross-site scripting vulnerabilities and a potential SQL injection that could be used to compromise a site, which were discovered by Marc-Alexandre Montpas of Sucuri, Helen Hou-Sandí of the WordPress security team, Netanel Rubin of Check Point, and Ivan Grigorov. It also includes a fix for a potential timing side-channel attack, discovered by Johannes Schmitt of Scrutinizer, and prevents an attacker from locking a post from being edited, discovered by Mohamed A. Baset.
Our thanks to those who have practiced responsible disclosure of security issues.
Download WordPress 4.2.4 or venture over to Dashboard → Updates and simply click “Update Now.” Sites that support automatic background updates are already beginning to update to WordPress 4.2.4.