The current_user_get_bug_filter function in core/current_user_api.php in MantisBT before 1.2.18 allows remote attackers to execute arbitrary PHP code via the filter parameter.
https://exchange.xforce.ibmcloud.com/vulnerabilities/99016
http://www.securityfocus.com/bid/71361
http://www.mantisbt.org/bugs/view.php?id=17875
http://www.debian.org/security/2015/dsa-3120
http://secunia.com/advisories/62101