lib/filelib.php in Moodle 2.1.x before 2.1.7 and 2.2.x before 2.2.4 does not properly restrict file access after a block has been hidden, which allows remote authenticated users to obtain sensitive information by reading a file that is embedded in a block.
https://exchange.xforce.ibmcloud.com/vulnerabilities/76956
http://www.securityfocus.com/bid/54481
http://secunia.com/advisories/49890
http://openwall.com/lists/oss-security/2012/07/17/1
http://git.moodle.org/gw?p=moodle.git%3Ba=commit%3Bh=c58c05ad4f22c6ee1e136a7d4caaddd809a7134d