Modeling Maritime Attack Surfaces: Why Your Next Target Might Be a Ship

TLDR: Maritime cyber-physical systems are increasingly vulnerable due to the convergence of legacy industrial control systems and modern networked IT. This research demonstrates how to use Model-Based Systems Engineering (MBSE) to map complex shipboard dependencies and identify critical attack vectors. By treating a vessel as an "apex system of systems," researchers can move beyond simple component testing to uncover systemic risks that traditional vulnerability scanners miss.

Modern maritime infrastructure is a massive, floating, interconnected network of industrial control systems (ICS) and IT assets. For years, the security of these vessels relied on "security by obscurity" and physical isolation. That era is over. As ships integrate more autonomous features, satellite communications, and remote monitoring, the attack surface has expanded from the bridge to the engine room and beyond.

The core problem for researchers and pentesters is the lack of domain knowledge and access. You cannot effectively audit a vessel if you do not understand how its subsystems—like the ballast, propulsion, or power management—interact. This research bridges that gap by creating a virtualized environment that models these dependencies, allowing for the simulation of cyber-attacks on critical maritime infrastructure.

Mapping the Maritime Attack Surface

When you approach a target like a container ship, you are not just looking at a single server or application. You are looking at a complex, cyber-physical system. The research presented at DEF CON 2025 utilizes Innostate, a cloud-based MBSE application, to model these systems. The goal is to define a "security domain boundary" around the system of interest (SOI).

The "iBox" method described in the talk is a practical way to visualize this. By placing an imaginary box around the SOI, you can identify every point where a signal, a person, or a piece of data crosses that boundary. If a connection breaks the plane of that box, it is a potential attack vector.

For a pentester, this changes the engagement model. Instead of just scanning for open ports on a satellite terminal, you are mapping the flow of data from the bridge to the engine control room. You are looking for:

• Digital vectors: Exploiting public-facing applications or misconfigured network gateways.
• Supply chain vectors: Compromising the software or hardware updates delivered to the vessel.
• Physical-to-digital vectors: Unauthorized personnel gaining access to physical control panels or maintenance ports.

The Reality of Systemic Failure

One of the most critical takeaways from this research is the concept of "system operational dependency." In a ship, subsystems are tightly coupled. A failure in the power management system can trigger a cascading failure in the navigation or communication systems.

Traditional vulnerability management often focuses on individual CVEs, such as those tracked in the NVD. However, in a maritime environment, the risk is rarely a single exploit. The risk is the interaction between systems. If you can manipulate data on a Modbus or serial bus, you might not just crash a single controller; you might cause a physical state change that compromises the entire vessel's safety.

To model these risks, the researchers advocate for Cyber-Hazard-Loss Analysis. This involves identifying what is "mission-critical" and mapping the dependencies that support those functions. If a specific controller is required for propulsion, that controller is a high-value target. If that controller depends on a network switch that is also used for crew Wi-Fi, you have found a critical path for an attacker.

Practical Application for Pentesters

If you find yourself on an engagement involving maritime or industrial control systems, stop looking for low-hanging fruit and start looking for the dependencies.

1. Identify the "Apex" systems: What are the core functions of the vessel? Propulsion, power, and navigation are usually at the top.
2. Map the coupling: How do these systems talk to each other? Are they using serial protocols, Ethernet, or proprietary wireless links?
3. Analyze the failure modes: What happens if you disrupt a specific communication link? Does the system fail-safe, or does it enter an unpredictable state?

Defenders, meanwhile, need to move toward a "security by design" approach. This means segmenting networks not just by function, but by criticality. It also means implementing robust monitoring that can detect anomalous traffic patterns between subsystems, not just at the network perimeter.

The maritime industry is playing catch-up with the rest of the world in terms of digital security. As researchers, we have an opportunity to define the standards for how these complex systems are audited and secured. The next time you are looking at a target with an industrial footprint, remember that the real vulnerability is rarely the software itself—it is the way that software is woven into the physical world. Start mapping the dependencies, and you will find the path to the core.