Acidcat CMS 3.4.1 does not properly restrict access to (1) default_mail_aspemail.asp, (2) default_mail_cdosys.asp or (3) default_mail_jmail.asp, which allows remote attackers to bypass restrictions and relay email messages with modified From, FromName, and To fields.
https://www.exploit-db.com/exploits/5478
https://exchange.xforce.ibmcloud.com/vulnerabilities/41921
http://www.securityfocus.com/bid/28868
http://www.securityfocus.com/archive/1/491129/100/0/threaded