MantisBT through 2.3.0 allows arbitrary password reset and unauthenticated admin access via an empty confirm_hash value to verify.php.
hyp3rlinx.altervista.org/advisories/MANTIS-BUG-TRACKER-PRE-AUTH-REMOTE-PASSWORD-RESET.txt
packetstormsecurity.com/files/159219/Mantis-Bug-Tracker-2.3.0-Remote-Code-Execution.html
www.openwall.com/lists/oss-security/2017/04/16/2
www.securityfocus.com/bid/97707
mantisbt.org/bugs/view.php?id=22690
www.exploit-db.com/exploits/41890/