Description
In Drupal 8 prior to 8.3.7; When using the REST API, users without the correct permission can post comments via REST that are approved even if the user does not have permission to post approved comments. This issue only affects sites that have the RESTful Web Services (rest) module enabled, the comment entity REST resource enabled, and where an attacker can access a user account on the site with permissions to post comments, or where anonymous users can post comments.
Remediation
References
Related Vulnerabilities
Ruby Permissions, Privileges, and Access Controls Vulnerability (CVE-2011-1005)
WordPress 4.4.x Same Origin Method Execution (SOME) Vulnerability (4.4 - 4.4.2)
Moodle Exposure of Sensitive Information to an Unauthorized Actor Vulnerability (CVE-2013-2243)
PHP Integer Overflow or Wraparound Vulnerability (CVE-2016-5095)