GRID GRID OT and SCADA Protocol Security

Question 1

Which communication protocol, widely used in US electric utility SCADA systems, was originally designed without authentication or encryption?

Accepted Answer

DNP3

Answer

DNP3 was developed for electric utilities and lacked authentication in its original design, making it vulnerable to replay and spoofing attacks without Secure Authentication v5.

Question 2

What is the primary security weakness of the Modbus TCP protocol in ICS environments?

Accepted Answer

It has no built-in authentication, authorization, or data integrity verification

Answer

Modbus TCP was designed purely for reliability in trusted networks and contains no mechanisms for authentication, authorization, or integrity checking.

Question 3

Which attack technique exploits the lack of authentication in Modbus to send unauthorized commands to a PLC?

Accepted Answer

Man-in-the-middle command injection

Answer

Without authentication, an attacker positioned on the network can intercept and inject malicious Modbus commands to alter PLC setpoints or coil states.

Question 4

What does the acronym 'PROFINET' stand for and which industry uses it most prominently?

Accepted Answer

Process Field Network — used primarily in discrete manufacturing automation

Answer

PROFINET (Process Field Network) is a Siemens-originated Ethernet-based protocol widely adopted in discrete manufacturing and factory automation environments.

Question 5

Which security control can detect unauthorized Modbus or DNP3 command sequences without disrupting live ICS traffic?

Accepted Answer

Passive protocol-aware IDS/NSM with OT-specific signatures

Answer

Passive OT-aware network security monitoring inspects protocol traffic inline without sending packets, detecting anomalous commands while preserving process availability.

(GRID) GIAC Response and Industrial Defense Practice Test

(GRID) GIAC Response and Industrial Defense Practice Test

GRID GRID OT and SCADA Protocol Security