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.
git.moodle.org/gw?p=moodle.git&a=search&h=HEAD&st=commit&s=MDL-50173
www.openwall.com/lists/oss-security/2015/09/21/1
www.securitytracker.com/id/1033619
github.com/moodle/moodle
github.com/moodle/moodle/commit/20ff15e22b4f0abebe1ab5fbfd1d681c88765e2a
github.com/moodle/moodle/commit/4015226623111438158fa762b7ce61f6cf677665
github.com/moodle/moodle/commit/731c2712e746053b1ca06b50118632305b447e02
github.com/moodle/moodle/commit/fa57105063129eed83bf09d83348681501ff5b64
moodle.org/mod/forum/discuss.php?d=320292
nvd.nist.gov/vuln/detail/CVE-2015-5268