Softing FG-100 PB PROFIBUS firmware version FG-x00-PB_V2.02.0.00 contains a hardcoded password for the root account, which allows remote attackers to obtain administrative access via a TELNET session.
packetstormsecurity.com/files/128976/Softing-FG-100-PB-Hardcoded-Backdoor.html
www.securityfocus.com/archive/1/533902/100/0/threaded
www.securityfocus.com/bid/70927
exchange.xforce.ibmcloud.com/vulnerabilities/98512
www.compass-security.com/fileadmin/Datein/Research/Advisories/CSNC-2014-005_softring_backdoor_account.txt