Moodle Improper Control of Generation of Code (Code Injection) Vulnerability - CVE-2013-5674
badges/external.php in Moodle 2.5.x before 2.5.2 does not properly handle an object obtained by unserializing a description of an external badge which allows remote attackers to conduct PHP object injection attacks via unspecified vectors as demonstrated by overwriting the value of the userid parameter.