MCP the 90’s Are Back: Critical Security Concerns with the MCP Protocol

From a #cybersecurity #leadership standpoint, the Message Control Protocol (MCP) sounds so friggen great NO one second, I meant Model Context Protocol these things are so close. It is 2025 all the security has been thought out of course, it’s been tried and tested. This will make life so much better for AI. NOPE! Sadly MCP represents a serious liability in any modern enterprise architecture. Originally designed for simplicity and rapid message transmission in legacy or embedded environments, MCP lacks the foundational security principles required to meet today’s threat landscape. As I look deeper I feel we have thrown ourselves back to the 1990’s where we did not have hackers and security issues as the internet and networks were places of safety. Enough of my sarcastic view, but it’s not far wrong as this has all the issues we have been wrestling with for the last 30 years. Below are a few of my main concerns:

Lack of Authentication and Integrity

So, from the start MCP was not designed with cryptographic authentication or integrity verification. Messages transmitted using MCP can be intercepted, altered, or spoofed with relative ease. This exposes systems to man-in-the-middle attacks, session hijacking, and command injection and just plain data loss.

No Encryption – Data in the Clear (90’s are calling)

MCP traffic is typically transmitted in plaintext, making it trivial for attackers to intercept sensitive information via passive network sniffing. In regulated environments, this violates data protection laws such as GDPR, HIPAA, and CCPA. This is the minimum issues outlined. If you are a bank, hospital or other regulatory stressed industry this a massive problem.

Protocol Ambiguity and Inconsistency

The snowflakes continue with MCP implementations because they often vary across vendors and systems, which opens the barn door to inconsistent parsing and undocumented behaviour a gift to keep security awake at night and adversaries looking to exploit buffer overflows and/or logic bugs.

 No Built-in Session Control (Sigh)

The absence of native session management makes it difficult to track, control, or log communications securely. This creates blind spots in detection and hampers forensic investigations after an incident and give the attackers the advantage. HOW long have we had session control since the early 90’s, and yes I am old enough to remember this.

Inadequate for Zero Trust Architectures

Our modern day our security and frameworks demand contextual access control, continuous verification, and encrypted transport (How our world has changed for the better unless you talk to anyone outside security.). It seems that MCP is fundamentally incompatible with Zero Trust principles or at least the articles I have read, and trying to bolt on security controls is often ineffective and introduces complexity and fragility. Anytime you bolt on security you end up with issues.

Unsupported or Abandoned Software

Once in place in a organisation MCP is rarely maintained or updated, meaning known vulnerabilities remain unpatched or even detected. This introduces once again perpetual technical debt and increases the organisation’s attack surface.

The Vender Bandwagon:

I can see the vendors lining up right now POC’ing a mvp of a product to get to market to fix a problem we should not have to fix. Lets brace ourselves for the Tidal wave of "MCP Security Solutions" that will flood the market and our mailboxes. We need people to work and think security and privacy by design.

What’s My Recommendation:

Not sure after reading everything above you want it. So here goes nothing. From a risk governance standpoint, continued use of MCP should trigger a high-risk finding in any cyber risk assessment and documented. It is imperative to prioritise the phased deprecation of MCP in favour of secure, standards-based protocols such as TLS-based messaging (e.g., HTTPS, MQTT over TLS, or secure gRPC). I would add temporary containment may include network segmentation, strict ACLs, and encrypted tunnel, but these are honestly short-term mitigations, not solutions. But we know once in place they become long-term solutions until something goes wrong.

Sadly MCP is a relic of a less hostile digital era and really has no place in a security-conscious, compliance-driven enterprise. I do feel that the cost of keeping it operational will be far exceeded by the cost of a preventable breach in the future.

It really is sad to see the security take a massive step backwards in 2025.

#MCPFail #MCP #CyberSecurityNightmare #CIONightmares #CISOLife #SecurityByDesign #CyberRiskManagement #Security101 #Back2The90s