Siemens SCALANCE S613 allows remote attackers to cause a denial of service (web-server outage) via traffic to TCP port 443.
https://www.exploit-db.com/exploits/44721/
https://ics-cert.us-cert.gov/advisories/ICSA-16-103-02
http://www.siemens.com/cert/pool/cert/siemens_security_advisory_ssa-751155.pdf