CyberCertPrepOT Security FundamentalsOT Fundamentals: Network Architecture & ProtocolsMEDIUMFree question
A vendor claims their Modbus TCP gateway is secure because the master must send the correct unit ID in every request. What is the flaw in that claim?
- A.Unit ID is a routing field with no secret or identity check
- B.Unit ID is validated against a certificate held on the client
- C.Unit ID is hashed by the gateway before each request
- D.Unit ID is rotated by the master near the end of each poll cycle
Why A is correct
The unit ID only selects a target device behind the gateway, such as a serial slave address. It carries no secret, signature, or certificate, so anyone who can reach the gateway can guess it.
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