Security updates released on Wednesday for the Drupal content management system (CMS) patch a “highly critical” vulnerability that can be exploited for remote code execution.
The security hole, tracked as CVE-2019-6340, is caused by the lack of proper data sanitization in some field types, which, in some cases, can allow an attacker to execute arbitrary PHP code, Drupal developers said. The issue was discovered by Samuel Mortenson of the Drupal Security Team.
Exploitation of CVE-2019-6340 is possible if the core RESTful Web Services module is enabled and it allows PATCH or POST requests. Exploitation is also possible if another web services module is enabled, such as JSON:API in Drupal 8 or RESTful Web Services or Services in Drupal 7.
Drupal 8.6.10 and 8.5.11 should address the vulnerability. Drupal 7 does not need to be updated, but there are some updates for Drupal 7 contributed modules that users have been advised to install.
“To immediately mitigate the vulnerability, you can disable all web services modules, or configure your web server(s) to not allow PUT/PATCH/POST requests to web services resources,” Drupal said in its advisory. “Note that web services resources may be available on multiple paths depending on the configuration of your server(s). For Drupal 7, resources are for example typically available via paths (clean URLs) and via arguments to the ‘q’ query argument. For Drupal 8, paths may still function when prefixed with index.php/.”