The rating component in Moodle through 2.6.11, 2.7.x before 2.7.10, 2.8.x before 2.8.8, and 2.9.x before 2.9.2 mishandles group-based authorization checks, which allows remote authenticated users to obtain sensitive information by reading a rating value.
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.