Why Your Next Maritime Pentest Needs to Look Beyond the Bridge

TLDR: Maritime operational technology (OT) systems are increasingly converging with IT networks, creating massive, often undocumented, attack surfaces. Researchers recently demonstrated that while remote exploitation of ship propulsion and power management systems is theoretically possible, it requires significant time and specialized knowledge. Pentesters should focus on identifying insecure remote access tools like TeamViewer and unsegmented network paths that bridge the gap between passenger Wi-Fi and critical engine control systems.

Maritime security is often discussed in abstract terms, but the reality of shipboard networks is far more chaotic than the industry admits. When you step onto a modern vessel, you are not just walking onto a ship; you are entering a floating, poorly segmented data center. The recent research presented at DEF CON 2024 regarding the MV Dali and similar vessels highlights a critical disconnect between the perceived security of these systems and their actual, messy implementation.

The Reality of Converged Networks

The primary issue is the convergence of IT and OT. Historically, a ship’s propulsion and power management systems were air-gapped, isolated, and relied on proprietary, serial-based communication. Today, those same systems are being integrated into broader ship networks to allow for remote monitoring, firmware updates, and crew entertainment. This integration is rarely done with a "security-first" mindset.

During the research, the team identified that these systems often rely on Modbus-RTU, a protocol that lacks native authentication or encryption. When you combine this with the fact that these systems are often bridged to the ship’s corporate or passenger network via IP-to-Serial converters, you create a direct path from a compromised laptop in a passenger cabin to the Programmable Logic Controllers (PLCs) managing the ship's engines.

The Attack Surface: Undocumented and Unmanaged

Pentesters often look for the "big" vulnerability, but in maritime environments, the biggest risk is the sheer volume of undocumented, legacy hardware. The research team found multiple instances of unmaintained access points and remote management tools that had been forgotten by the crew.

One of the most glaring examples was the presence of TeamViewer on critical control systems. In many cases, the company had stopped paying for the service years ago, yet the software remained installed, active, and connected to the internet via the ship’s VSAT link. This is a classic case of Broken Access Control, where an attacker does not need a sophisticated zero-day exploit to gain a foothold. They simply need to find the credentials or exploit the outdated, unpatched remote access software.

If you are conducting a pentest on a vessel, your first step should be a thorough network discovery. Do not assume the network topology matches the documentation provided by the ship’s IT staff. Use tools to map the VLANs and identify where the IT network touches the OT network.

# Example of scanning for common industrial protocol ports
nmap -p 502 --script modbus-discover <target_ip>

The "Human in the Loop" Defense

Despite the technical vulnerabilities, the research confirms that hacking a ship is not a "one-click" affair. It requires a deep understanding of the specific OT architecture, the ability to interpret serial data, and, in many cases, physical presence. The systems are designed to be resilient, and there is almost always a human in the loop.

For instance, even if an attacker manages to inject a command into the power management system, the ship’s crew can often override the digital controls with physical switches. This is a crucial point for researchers to understand: the digital layer is only one part of the security posture. The physical, manual overrides are the final line of defense.

What This Means for Your Next Engagement

If you find yourself on a maritime engagement, stop looking for web application vulnerabilities and start looking for the physical and logical bridges between networks. Look for the IP-to-Serial converters tucked away in cabinets. Check for remote access software that has not been updated in years. Investigate the VLAN configurations to see if the passenger Wi-Fi is truly isolated from the engine room controls.

The industry is slowly moving toward better standards, such as the IACS Unified Requirements for cyber resilience, but these regulations only apply to new builds. The vast majority of the global fleet is still running on legacy, insecure, and poorly documented systems.

Your job as a researcher is to expose these gaps before someone with malicious intent does. The next time you are on a ship, don't just look at the screens on the bridge. Open the cabinets, trace the cables, and find out what is actually running on the other side of that serial connection. You might be surprised at what you find.