Directory traversal vulnerability in repository/filesystem/lib.php in Moodle through 2.2.11, 2.3.x before 2.3.10, 2.4.x before 2.4.7, and 2.5.x before 2.5.3 allows remote authenticated users to read arbitrary files via a .. (dot dot) in a path.
https://moodle.org/mod/forum/discuss.php?d=244481
https://euvd.enisa.europa.eu/vulnerability/EUVD-2013-4383
http://openwall.com/lists/oss-security/2013/11/25/1
http://git.moodle.org/gw?p=moodle.git&a=search&h=HEAD&st=commit&s=MDL-41807