thinQmaster Virtual testing partner Adaptive practice exams that find your weak spots and drill them. Every answer explained. From $69
Enroll

thinQmaster

Find your exam

Five questions free, before you decide.

Step 1 · choose a vendor

In one of our camps? Your practice exams come with the tuition — they are on your study page already.

Application & OT Security · Intermediate

MQTT Security

Protecting the MQTT publish/subscribe messaging protocol widely used by IoT devices.

Definition

MQTT brokers (TCP 1883 cleartext, 8883 over TLS) often ship without authentication, letting anyone subscribe to all topics with the # wildcard. Secure deployments use TLS, per-device credentials or client certificates, topic-level authorization (ACLs) and disabling anonymous access.

Example

A broker exposed on port 1883 without authentication leaks all sensor and command topics.

Exam tip

Know ports 1883 vs 8883 and that topic ACLs are needed.

Related terms