What is MQTT?
MQTT is a lightweight publish/subscribe protocol often used for IoT and telemetry messaging.
Common security issues
Anonymous publish/subscribe due to missing authentication
Weak topic ACLs enabling data theft or device control signals
Retained messages leaking credentials or operational data
Plaintext transport when TLS is not enforced
Enumeration
Detect brokers, map topics, and extract broker system info
MQTT Service Detection and Version Identification
MQTT Topic Discovery and Structure Mapping
Vulnerability Discovery
Guides for finding MQTT auth flaws, weak creds, and plaintext transport
MQTT Plaintext Transport Detection
MQTT Unauthenticated Access
MQTT Weak and Default Credential Check
Exploitation
Anonymous subscribe, unauthorized publish, retained message harvest guides
MQTT Anonymous Subscribe and Traffic Harvest
MQTT Retained Message Harvest
MQTT Unauthorized Publish and Device Control
Data Exfiltration
Capture and exfiltrate MQTT topic payloads including credentials and teleme