MCP Servers Still Run Critical Infrastructure—Here’s How to Secure Them

There is so much that goes into the big space of cybersecurity with its big brands Windows servers, Linux, web applications, and APIs. However, there exists another realm which silently works in the backend systems of multiple industries: MCP servers.

If you're curious about what MCP servers are and why they're important for cybersecurity, you're not alone. This article will take you through what MCP is, what the Vulnerable MCP Project is, and most importantly what we can learn in order to effectively secure MCP-based systems.

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Prefer watching instead of reading? Here’s a quick video guide

https://youtu.be/CPuJsamkdUI?embedable=true

What Is MCP?

MCP (Master Control Program) is a multi-user, multi-tasking operating system primarily found in high-reliability applications. MCP originated with Burroughs Corporation, which was absorbed into Unisys. MCP is one of the first high-level language-based OSes and is commonly implemented in financial markets, government computers, and industrial facilities.

Imagine MCP as an "old-school but robust" operating system that's still utilized where uptime and data integrity are paramount.

What Is the Vulnerable MCP Project?

The Vulnerable MCP Project is a project that resembles other teaching security projects such as OWASP's Juice Shop or DVWA (Damn Vulnerable Web App). It's meant to mimic a production MCP server environment with deliberately open vulnerabilities for the sake of:

• Educating system admins on how to spot risks in MCP environments
• Educating security professionals in how to protect legacy systems
• Providing a sandboxed playground for pentesters and researchers

In summary, it's a lab setup that allows us to see the weak spots of MCP so we can better protect real systems.

Legacy systems are usually forgotten in security plans. Lots of companies continue to use outdated infrastructures because they're stable, quick, and costly to replace. But attackers adore these systems because they're usually forgotten no updates, no hardening, and minimal monitoring.

Securing MCP servers is essential for:

• Compliance (particularly in finance and healthcare)
• Uptime and reliability
• Preventing data breaches from legacy infrastructure

Common Vulnerabilities in MCP Servers

These are some of the main vulnerabilities seen in the Vulnerable MCP Project:

Insecure Authentication Mechanisms

Most MCP systems employ outdated username/password combinations. At times, there's no protection against brute force, and attackers can attempt hundreds of passwords without being halted.

Solution: Mandate strong password policies and rate-limit login attempts.

Obsolete Encryption Protocols

Some systems employ outdated cryptographic protocols such as DES or plaintext connections.

Solution: Upgrade to current cryptographic practices (such as AES and TLS 1.3), even on outdated systems.

Hardcoded Admin Credentials in Scripts

Old maintenance scripts can have hardcoded admin credentials.

Solution: Use secrets management tools or environment variables to securely store sensitive information.

No Logging or Monitoring

Such systems do not have real-time monitoring or logging, so breaches can remain undetected for weeks or months.

Integrate your MCP environment with a SIEM tool (such as Wazuh or Splunk) to provide logging and alerting.

Unpatched System Software

Legacy systems often operate on old software that has not been patched for known vulnerabilities.

Solution: Audit and patch regularly, even if you need to test in a sandboxed environment before applying.

No Role-Based Access Control (RBAC)

Too many MCP installations operate with all users being granted admin rights, particularly in a test environment.

Solution: Enforce hard least privilege policies and establish role-based access levels.

Tools and Techniques for Securing MCP

Securing MCP systems might look daunting, yet a number of contemporary tools and practices can assist:

• Employ Port Scanners with MCP Awareness: Scanners such as Nmap can identify open services, but ensure that you understand what services MCP employs such as custom ports or legacy protocols.
• Vulnerability Scanners: Although popular tools such as Nessus or OpenVAS may not have MCP-specific services out of the box, you can still employ them to identify network-level vulnerabilities.
• SSH Hardening: Certain MCP installations employ remote access through SSH or telnet. Disable telnet.
• Network Segmentation: Isolate MCP systems on their own VLANs or segments with firewall configurations to restrict access from the general network.

Real-World Application: How a Bank Could Secure Its MCP System

Suppose a regional bank employs MCP to handle transactions. Here's how they could protect their system with lessons from the Vulnerable MCP Project:

• Audit and review user accounts to eliminate inactive users
• Enable logging and route it to a central SIEM
• Shift credentials into a secrets manager such as HashiCorp Vault
• Test patches in a staging environment prior to deployment
• Train personnel with simulations based on the Vulnerable MCP Project

How to Practice Securing MCP Servers Yourself

• Want to try this yourself? Here's how you can do it:
• Download the Vulnerable MCP Project if available to the general public (check GitHub or security boards)
• Set it up on a virtual machine or sandboxed lab
• Use tools like:
• Wireshark to analyze traffic
• Metasploit to test known vulnerabilities
• OSINT tools to simulate external attacker reconnaissance

Always ensure you’re working in a controlled, non-production environment.

Key Takeaways

• MCP servers are still in use today, especially in industries where stability trumps modernity
• Legacy systems like MCP are often neglected in security planning
• The Vulnerable MCP Project offers a secure sandbox in which to experiment with real-world attacks on these systems
• Securing MCP servers requires a combination of contemporary security best practices and legacy-specific hacks

Final Thoughts

Securing new tech is important but we can't overlook the old giants humming along in the background. MCP isn't cool, but it matters. Projects like the Vulnerable MCP Project are priceless in helping us learn about and secure these systems.