Port 802Modbus Application Protocol Secure

Encrypted Modbus communications for industrial automation, normally using TLS on port 802.

transport: tcp · udp
in transit: encrypted
assignment: official
risk: 6/10
lookups: 0

also known as mbap-s, Modbus Security, Modbus/TLS

Technical Details

what runs on :802

Modbus Application Protocol Secure normally carries Modbus/TCP through a TLS session, using port 802 instead of the conventional cleartext Modbus/TCP port 502. After the TLS handshake, Modbus application messages retain the usual transaction, protocol, length, and unit identifiers in the MBAP framing; certificate and TLS-version details depend on the implementation. The IANA assignment covers TCP and UDP, although standard Modbus Security deployments are generally associated with TLS over TCP.

Security Information

exposure of :802

risk score

6/ 10risk

treat as sensitive. widely scanned and regularly exploited when reachable — restrict it to known sources.

security averages 3.3 across 303 ports — this one sits 2.7 above.

in transit

encrypted

payloads are protected on the wire

assignment

official

registered with iana for this service — scanners fingerprint it by number

reachable over

tcp · udp

udp is connectionless — source addresses are trivially spoofed and it is a reflection favourite

security overview

Encryption and endpoint authentication reduce interception, credential theft, and command tampering, but the service still exposes an industrial control protocol capable of reading process data and issuing device commands. It should normally be restricted to trusted control networks or tightly controlled VPN paths rather than exposed directly to the public internet, with certificate validation and least-privilege device access enforced.

Record

iana registry entry

port: :802
service: Modbus Application Protocol Secure
transport: TCPUDP
encryption: tls / encrypted
assignment: iana registered
risk: 6/10risk
category: Security IoT
usage: This port is used by Modbus Security clients and servers to protect Modbus exchanges between industrial controllers, gateways, and supervisory systems. It is most commonly encountered in operational technology networks, with Modbus/TCP on port 502 used for unprotected deployments.
lookups: 0rank 994
added: 2026-09-10
updated: 2026-09-10
references: IANA service name registry — port 802

Something wrong?

This record is maintained by the engineers who use port 802. Every field on it is editable — change what's wrong, say how you know, and a reviewer publishes it, usually within a minute. Last touched 2026-09-10.

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Related Ports

all 303 in security →

the 8 most looked-up other ports in security — 303 ports carry that label.

port	service	proto	category	risk	views
:8881	Atlasz Secure Server	TCP	Web Services	caution	67.6k
:443	HTTPS	TCPtls	Web Services	caution	65.9k
:8291	Winbox MikroTik Admin	TCP	Security	caution	62.9k
:3268	Microsoft Global Catalog (GC)	TCPUDP	Security	caution	54.6k
:135	Microsoft EPMAP	TCPUDP	Security	caution	51.9k
:3128	Squid Proxy HTTP	TCP	Web Services	caution	45.8k
:8080	HTTP Alternate	TCPtls	Web Services	caution	44.9k
:7000	Vuze HTTPS Tracker	TCPtls	Security	caution	28.9k

risk mix of the 8 listed

caution100%

3 of 8 encrypted

Port :802Modbus Application Protocol Secure

Technical Details

Security Information

Related Ports

Port 802Modbus Application Protocol Secure