grade/edit/outcome/edit_form.php in Moodle 1.9.x through 1.9.19, 2.1.x before 2.1.10, 2.2.x before 2.2.7, 2.3.x before 2.3.4, and 2.4.x before 2.4.1 does not properly enforce the moodle/grade:manage capability requirement, which allows remote authenticated users to convert custom outcomes into standard site-wide outcomes by leveraging the teacher role and using the re-editing feature.
https://moodle.org/mod/forum/discuss.php?d=220158
http://openwall.com/lists/oss-security/2013/01/21/1
http://git.moodle.org/gw?p=moodle.git&a=search&h=HEAD&st=commit&s=MDL-27619