Drupal has released an advisory to address several vulnerabilities in Drupal versions 7.x and 8.x. A remote attacker could exploit one of these vulnerabilities to take control of an affected system. (Advisory ID: DRUPAL-SA-CORE-2017-003)
- PECL YAML parser unsafe object handling - PECL YAML parser does not handle PHP objects safely during certain operations within Drupal core. This could lead to remote code execution.
- File REST resource does not properly validate - The file REST resource does not properly validate some fields when manipulating files. A site is only affected by this if the site has the RESTful Web Services (rest) module enabled, the file REST resource is enabled and allows PATCH requests, and an attacker can get or register a user account on the site with permissions to upload files and to modify the file resource.
- Files uploaded by anonymous users into a private file system can be accessed by other anonymous users - Private files that have been uploaded by an anonymous user but not permanently attached to content on the site should only be visible to the anonymous user that uploaded them, rather than all anonymous users. Drupal core did not previously provide this protection, allowing an access bypass vulnerability to occur. This issue is mitigated by the fact that in order to be affected, the site must allow anonymous users to upload files into a private file system.
Drupal core 7.x versions prior to 7.56
Drupal core 8.x versions prior to 8.3.4
If you use Drupal 7.x, upgrade to Drupal core 7.56
If you use Drupal 8.x, upgrade to Drupal core 8.3.4