4840
OPC UA
High RiskTCP — Other
Port Overview
Port Number
4840
Service Name
OPC UA
Transport Protocol
TCP
Category
Other
Security Risk
High
Port Range
Registered (1024-49151)
What is Port 4840?
Port 4840 is the default port for OPC UA (OPC Unified Architecture), an industrial communication protocol used in manufacturing automation, SCADA systems, and Industrial IoT. OPC UA provides a platform-independent, secure, and reliable mechanism for data exchange between industrial devices and software. Exposure of this port in ICS/SCADA environments poses serious industrial control system security risks.
TCP
Other
Security Considerations
Port 4840 (OPC UA) is classified as high risk. This port is a common target for automated scanning and brute-force attacks. If you must expose it, restrict access to known IP addresses.
Recommendation: Use firewall rules to whitelist trusted IPs. Enable rate limiting and intrusion detection.