Crucial Exams

Certified Ethical Hacker (CEH) Practice Question

During a penetration test of a smart-lighting system, you capture clear-text MQTT traffic on TCP port 1883 that shows every fixture authenticating with the hard-coded credential "admin/admin." Firmware updates that add TLS and credential management will not be ready for several months. Which compensating control will most effectively reduce the chance that an attacker on the corporate LAN can hijack the lights during this period?

  • Enable sticky MAC and limit each switch port to a single learned address.

  • Deploy a signature-based IDS rule that triggers on the string "admin" in MQTT payloads.

  • Implement DNS sinkholing to block external queries from the lighting controllers.

  • Isolate the lighting controllers and MQTT broker in their own VLAN and restrict inter-VLAN routing to approved management hosts only.

Certified Ethical Hacker (CEH)
Mobile Platform, IoT, and OT Hacking
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