Directory traversal vulnerability in file.php in Moodle 1.4.2 and earlier allows remote attackers to read arbitrary session files for known session IDs via a .. (dot dot) in the file parameter.
https://exchange.xforce.ibmcloud.com/vulnerabilities/18550
https://euvd.enisa.europa.eu/vulnerability/EUVD-2004-1422
http://www.securityfocus.com/bid/12120