A hacker is able to eavesdrop on administrative sessions to remote IoT sensors. Which of the following has most likely been misconfigured or disabled?

In many Internet of Things (IoT) architectures, remote sensors and devices are managed as a group. To secure communications, a Virtual Private Network (VPN) using the Internet Protocol Security (IPSec) suite is often established between the management station and the remote network gateway. This creates a secure tunnel, encrypting all traffic. Within this tunnel, administrators might use lightweight, unencrypted protocols for sessions, assuming the tunnel provides confidentiality. If the IPSec tunnel is misconfigured or disabled, this layer of protection is lost, and the administrative session traffic is transmitted in cleartext over the public internet, making it vulnerable to eavesdropping.

A. Secure Shell (SSH): SSH is an encrypted protocol. If SSH were being used for the administrative session, eavesdropping would not be possible, even if a network-level tunnel was not active.
C. Telnet: While using the unencrypted Telnet protocol allows eavesdropping, in a properly designed IoT architecture, its use is often restricted to within a secure tunnel (like IPSec). The failure is the misconfiguration of the tunnel that exposes the traffic.
D. Virtual private network (VPN): This is a general term for the technology. IPSec is a specific and common protocol suite used to implement network-layer VPNs, making it a more precise and technically accurate answer.

1. National Institute of Standards and Technology (NIST)

NISTIR 8259A

IoT Device Cybersecurity Capability Core Baseline

May 2020. Section 3.2

"Device Security

" subsection "3.2.1 Data Protection

" states: "The IoT device should use a secure and trusted communication channel for all remote network connections... This may be accomplished by the device itself (e.g.

by using TLS) or by a trusted component in the device’s immediate network environment (e.g.

a network gateway that implements a VPN)." This reference supports the architectural pattern where a VPN (often using IPSec) is the primary security control. Its failure would expose underlying communications.

2. Kent

S.

& Seo

K. (2005). RFC 4301: Security Architecture for the Internet Protocol. Internet Engineering Task Force (IETF). Section 1.1

"Benefits of IPsec

" states that IPSec can provide confidentiality (encryption) for all traffic at the IP layer. A misconfiguration or disabling of this service would negate this benefit

exposing the data payloads to eavesdropping.

3. Stallings

W. (2017). Cryptography and Network Security: Principles and Practice (7th ed.). Pearson. Chapter 20

"IP Security

" details how IPSec provides security for all traffic between two endpoints (e.g.

a gateway and a host). The text explains that IPSec's transport and tunnel modes are designed to prevent attacks like eavesdropping. The scenario in the question describes a failure of this preventative mechanism.