Zero-Day: The threat with no warning
Article 1 from the series "It’s a jungle out there: Navigating the digital danger zone"

In today’s world of constant connectivity, cyber risks are no longer confined to large corporations or government agencies. The rise of mobile devices, rapid network expansion, and the ever-growing number of digital users have opened up new avenues for attackers. These risks have become widespread and accessible.
Today, ships, maritime operators, crews, offshore platforms, and remote systems are just as likely to be targeted by cyberattacks as major cities or financial hubs.
Utilising extracts from Valour Consultancy’s The Future of Maritime Cybersecurity 2025 report, Telemar set out to clarify what cyber security really means in the maritime and energy context. What exactly is ransomware? How does phishing affect ship crews? Can a DDoS attack cut off a vessel in the middle of the ocean? What does an SQL Injection mean in a shipboard logistics system?
This series aims to demystify the most common cyber threats affecting maritime, energy, and remote operational environments. In a world where connectivity is considered a strength, it can just as easily become a point of vulnerability if not managed responsibly.
Through its global network and solutions, Telemar delivers not just connectivity but also protection, safeguarding critical systems and information from ship to shore, from platform to data center.
In the upcoming articles, we’ll explore each type of attack and how they impact daily operations in real world scenarios.
Zero-Day: The threat with no warning
Zero-Day vulnerabilities are security flaws in software, hardware, or firmware that are unknown to the vendor at the time attackers first discover and exploit them. Since no patch exists yet, these vulnerabilities can be used immediately, with no warning.
Why it’s dangerous:
In industries that rely on stability and continuous system uptime (like maritime and energy) Zero-Day vulnerabilities allow attackers to bypass defenses, infiltrate systems, and carry out sabotage, espionage, or data theft undetected.
Ships, in particular, often depend on specialized software that is updated infrequently, making Zero-Day vulnerabilities likely to persist longer than in traditional IT environments.
Examples from the field:
- A navigation system uses a component with an undiscovered flaw, allowing an attacker to access it without authentication.
- A platform runs outdated remote management software that contains a vulnerability exploited before a patch is available.
- A new malware strain leverages a Zero-Day flaw to bypass antivirus protections and spreads through the ship’s LAN.
How to protect against it:
- Use behaviour-based anomaly detection tools, such as Marlink Cyber Detection & Response
- Perform regular updates of software and firmware through secure, verified channels
- Segment networks to limit lateral movement in case of a breach
With Zero-Day threats, timing is everything. If not detected early, the damage may go unnoticed but leave lasting consequences.
