312-50 Question 419
Single answer▪ IoT Attack CountermeasuresA hospital is deploying hundreds of IP-based infusion pumps and patient monitors on its clinical network. During a security assessment, you discover that many devices expose web management interfaces, use outdated firmware, and communicate with backend systems over unencrypted protocols. The hospital cannot immediately replace the devices because of operational constraints. Which countermeasure would most effectively reduce the risk of compromise and lateral movement while preserving device functionality?
- A
Place all IoT medical devices on a dedicated network segment with strict ACLs/firewall rules, allow only required communication paths, and manage firmware updates through a controlled patching process
- B
Enable WEP on the wireless network used by the devices so legacy equipment can connect without compatibility issues
- C
Allow the devices unrestricted access to the internal network, but change their default passwords during the next maintenance cycle
- D
Expose the device management interfaces to the internet through NAT so vendors can troubleshoot issues remotely without a VPN
Show answer and explanation
Correct answer: A
Explanation
The best answer is to segment the IoT devices and restrict communications while maintaining a controlled firmware-management process. In real-world IoT environments, especially healthcare settings with safety-critical devices, immediate replacement is often not possible. Therefore, compensating controls are essential. Industry best practices from sources such as NIST guidance on IoT device cybersecurity and network security architecture emphasize asset isolation, least-functionality, least-privilege communications, secure management access, and timely patching or firmware updates. Segmentation does not fix unencrypted application protocols by itself, but it significantly reduces exposure and limits post-compromise movement. By contrast, WEP is obsolete, unrestricted access enables pivoting, and internet-exposed management interfaces create unnecessary risk.
- A. Correct.
Correct. Network segmentation is one of the most effective IoT countermeasures, especially when devices cannot be immediately replaced or fully hardened. Isolating medical IoT devices in a dedicated VLAN or micro-segment and enforcing strict ACLs/firewall rules reduces the chance that a compromised device can be used for lateral movement into other hospital systems. Limiting communications to only necessary backend servers follows least privilege and reduces attack surface. A controlled firmware update process is also essential because outdated firmware often contains known vulnerabilities. This approach preserves functionality while materially improving security.
- B. Incorrect.
Incorrect. WEP is deprecated and cryptographically broken. Enabling WEP weakens wireless security and increases the risk of unauthorized access. Although legacy compatibility is a common operational concern in IoT environments, choosing an insecure protocol is not an appropriate countermeasure. Modern best practice is to use stronger wireless protections such as WPA2/WPA3 where supported, along with segmentation and access controls.
- C. Incorrect.
Incorrect. Changing default passwords is important, but by itself it does not adequately address the broader risks in the scenario. The devices are still running outdated firmware, exposing management interfaces, and using insecure communications. Unrestricted internal network access leaves the environment vulnerable to pivoting and lateral movement if one device is compromised. This option reflects the misconception that credential changes alone are sufficient for IoT security.
- D. Incorrect.
Incorrect. Exposing management interfaces to the internet significantly increases the attack surface and is contrary to secure remote administration practices. NAT is not a security control. Vendor access, if needed, should be provided through secure mechanisms such as a VPN, jump host, strong authentication, and tight access restrictions. Public exposure of management portals is a common cause of IoT compromise.