When viewing ratings the group access was not properly checked allowing users from other groups to view ratings. Affected versions are 2.9 to 2.9.1, 2.8 to 2.8.7, 2.7 to 2.7.9 and earlier unsupported versions. Upstream patch: https://git.moodle.org/gw?p=moodle.git&a=search&h=HEAD&st=commit&s=MDL-50173
*** This bug has been marked as a duplicate of bug 1264861 ***