MANUFACTURING CYBER RISK STORY #4
The Open Door: Why Internet-Exposed Manufacturing Networks Stay at Risk
Network exposure grows when public services, open ports and weak perimeter controls create reachable pathways into critical manufacturing environments.
Why manufacturing data exposure often starts quietly.
Most manufacturers do not intentionally leave their environments exposed. Open services usually appear for practical reasons: a support team needs quick access, a vendor needs a temporary connection, or a remote tool gets deployed in a hurry and never gets reevaluated. That is what makes external exposure so dangerous. It rarely begins as a dramatic security failure. More often, it starts as convenience and ends as access. This is why “The Open Door” matters. It is not really a story about ports. It is a story about how small exposure decisions create larger business risk.
When Accent Consulting looked at manufacturing network exposure, one pattern stood out quickly: internet-facing services were not rare exceptions. They were recurring openings. At the center of this story were 60 Remote Desktop Protocol (RDP) ports left exposed to the internet, alongside broader firewall and network weaknesses that accounted for 7% of all identified issues. An open port may sound technical, but in a manufacturing environment it is operational. It can become a direct path toward scheduling systems, administrative access, vendor tools and in some cases the networks that support production itself.
21
Manufacturers
Assessed
7%
Of Issues Are
Network/Firewall Related
60
Open RDP
Ports Identified
118
Firewall & Network Vulnerabilities
WHERE MANUFACTURERS DIFFER
Why external exposure matters in manufacturing.
External exposure is one of the clearest and most immediate sources of cyber risk in manufacturing. When services are reachable from the internet, attackers do not need insider knowledge or sophisticated access. They only need time, scanning tools and a visible target.
That risk becomes much more serious when internet-facing systems sit too close to production-connected environments. A remote access tool, exposed administrative service or weakly governed firewall can turn a simple opening into a path toward plant operations, business systems or sensitive data. In manufacturing, exposed services are not just IT issues. They can become operational issues very quickly.
NETWORK SEGMENTATION
Why IT and OT separation is so important.
Manufacturers should separate IT networks from equipment and OT networks because segmentation helps contain risk. If an internet-facing issue affects one part of the business, it should not become a direct route to manufacturing equipment, production support systems or plant operations.
This is why network boundaries matter so much. Weak segmentation increases the chance that exposed services, remote access tools or inherited trust relationships can extend farther into the environment than leaders expect. Strong IT and OT separation helps reduce the likelihood that a perimeter issue becomes a production problem.
REMOTE ACCESS RISK
Why open RDP and publicly reachable services are risky.
Remote Desktop Protocol is useful because it allows administrators, support teams and vendors to access systems quickly. That same convenience is what makes it attractive to attackers. The source material identifies RDP as the #1 entry point for ransomware, notes that 74% of ransomware attacks involve RDP entry and documents 60 RDP ports left open to the internet.
That is not just a technical detail. It represents repeated opportunities for scanning, brute-force attempts, credential attacks and unauthorized access. The broader issue extends beyond RDP alone. Publicly accessible management interfaces, exposed database ports and non-encrypted external web traffic all increase the number of reachable paths attackers can test. What looks like a small networking issue is often a larger perimeter governance problem.
PERIMETER GOVERNANCE
What the data suggests about perimeter governance.
The data behind this story includes 118 firewalls and network issues, along with vulnerable publicly accessible services and exposed ports. That suggests the real problem is not one protocol alone — it is how the external perimeter is being managed. In many cases, the exposure comes from accumulated exceptions, inherited configurations or services that remained reachable longer than intended. Over time, those decisions add up, in terms of risk.
What this represents is repeated opportunities for scanning, brute-force attempts, credential attacks and unauthorized access. The broader issue extends beyond RDP alone. Publicly accessible management interfaces, exposed database ports and non-encrypted external web traffic all increase the number of reachable paths attackers can attack.
COMMON QUESTIONS
What You Can Do Next
What are cybersecurity best practices for managing internet exposure?
Cybersecurity best practices for managing internet exposure start with visibility, restriction and continuous review. Manufacturers reduce risk by maintaining a current inventory of internet-facing assets, removing unnecessary open ports, securing remote access behind VPN or secure gateways, reviewing firewall rules regularly and treating public exposure as an active business risk. The goal is not perfection, but reducing the number of reachable services attackers can discover and test.
How can manufacturing companies improve their cybersecurity defenses through perimeter control?
Manufacturers can improve their cybersecurity defenses by reducing what is visible and reachable from the public internet. A stronger approach includes identifying all exposed services, eliminating direct RDP exposure, restricting public admin interfaces, encrypting external web traffic, segmenting business and production-connected networks and monitoring for scanning and repeated access attempts.
What are the biggest internet exposure challenges in manufacturing?
Manufacturers often face internet exposure challenges such as temporary vendor access that remains in place, firewall exceptions that accumulate over time, legacy services left exposed for convenience, remote access tools published directly to the internet and limited visibility into what is externally reachable. These constraints are common, but so is the exposure they create.
Why are open RDP ports still a major manufacturing risk?
Because they create direct, reachable paths into systems. Open RDP services are widely scanned, commonly targeted and often used as an entry point for brute-force attempts, credential attacks and ransomware activity. The findings identified 60 open RDP ports, showing that remote access exposure remains a practical and ongoing risk across manufacturing environments.
How do we prevent ransomware attacks on manufacturing equipment through better perimeter security?
Attackers do not always need advanced exploits when reachable services are already exposed. Manufacturers can reduce ransomware risk by removing open RDP from the public internet, enforcing MFA on remote access, securing administrative functions behind VPN or secure gateways, improving segmentation between IT and production-connected systems and monitoring for suspicious external access behavior.
LEADERSHIP NEXT STEPS
What manufacturers should do next.
Reduce external exposure by tightening remote access, strengthening segmentation and improving control over what internet-facing systems remain reachable.