An issue was discovered on Siemens SICAM RTUs SM-2556 COM Modules with the firmware variants ENOS00, ERAC00, ETA2, ETLS00, MODi00, and DNPi00. The integrated web server (port 80/tcp) of the affected devices could allow unauthenticated remote attackers to execute arbitrary code on the affected device.
https://www.siemens.com/cert/pool/cert/siemens_security_advisory_ssa-164516.pdf