mod/assign/locallib.php in the assignment module in Moodle 2.3.x before 2.3.7 and 2.4.x before 2.4.4 does not consider capability requirements during the processing of ZIP assignment-archive download (aka downloadall) requests, which allows remote authenticated users to read other users' assignments by leveraging the student role.
https://moodle.org/mod/forum/discuss.php?d=228930
http://openwall.com/lists/oss-security/2013/05/21/1
http://lists.fedoraproject.org/pipermail/package-announce/2013-May/107026.html
http://lists.fedoraproject.org/pipermail/package-announce/2013-May/106988.html
http://lists.fedoraproject.org/pipermail/package-announce/2013-May/106965.html
http://git.moodle.org/gw?p=moodle.git&a=search&h=HEAD&st=commit&s=MDL-38443