lib/classes/grades_external.php in Moodle 2.7.x before 2.7.3 does not consider the moodle/grade:viewhidden capability before displaying hidden grades, which allows remote authenticated users to obtain sensitive information by leveraging the student role to access the get_grades web service.
Source: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-7831
Reference (s):
- http://git.moodle.org/gw?p=moodle.git&a=search&h=HEAD&st=commit&s=MDL-47766
- https://moodle.org/mod/forum/discuss.php?d=275153
- MLIST:[oss-security] 20141117 Moodle security issues are now public
- URL: http://openwall.com/lists/oss-security/2014/11/17/11
- SECTRACK:1031215