WordPress allows remote attackers to obtain sensitive information via a direct request for wp-admin/admin-functions.php, which reveals the path in an error message.
https://exchange.xforce.ibmcloud.com/vulnerabilities/32881
http://www.securityfocus.com/archive/1/462249/100/0/threaded
http://www.securityfocus.com/archive/1/462230/100/0/threaded