Colonial Pipeline shows why critical infrastructure auth must modernize

At a glance

What this is: This is an analysis of how the Colonial Pipeline attack sharpened the case for modern authentication, machine identity management, and stricter compliance in critical infrastructure.

Why it matters: It matters because IAM teams must treat human and machine authentication together when legacy systems, regulated environments, and operational resilience all depend on stronger identity controls.

👉 Read Axiad's analysis of the Colonial Pipeline attack and identity risk

Context

The core problem is legacy authentication and machine access that outlast the controls built to protect them. When passwords remain the default and machine identities are not managed as first-class identities, critical infrastructure becomes easier to reach and harder to contain.

For IAM and security teams, the Colonial Pipeline case is a reminder that identity risk is not limited to people. It spans human login assurance, device trust, certificate-based machine authentication, and the governance needed to keep older systems from becoming permanent exceptions.

Key questions

Q: How should organisations modernize authentication in critical infrastructure without breaking operations?

A: Start with the systems whose access paths create the largest operational blast radius, then replace password-first access with stronger authentication that fits the environment. Keep legacy systems stable by sequencing change, not by preserving weak controls indefinitely. Modernization succeeds when security, operations, and governance share a migration plan.

Q: Why do passwords create such a large risk in operational environments?

A: Passwords are easy to steal, reuse, or intercept, so one compromised login can expose multiple systems. In operational environments, that risk is amplified because access often reaches systems that support physical services and production workflows. The governance issue is not just credential weakness, but the scale of the reachable impact.

Q: What should security teams do when device identities are spread across operational technology systems?

A: Treat device identities as managed credentials with clear ownership, issuance, renewal, and revocation rules. If those controls are missing, a single compromised device can become a trusted route into the network. Governance should cover certificates and keys with the same discipline used for privileged human access.

Q: Who is accountable when machine identity controls fail in critical infrastructure?

A: Accountability should sit with the teams that own the device estate, the identity lifecycle, and the operational risk of the connected systems. Compliance frameworks can require stronger authentication, but governance only works when ownership is explicit and audit-ready. If no one owns revocation and trust decisions, the control will drift.

Technical breakdown

Legacy systems and authentication drift

Legacy systems often persist because they are embedded in operations, not because they are secure. Over time, authentication methods drift from current assurance expectations, while knowledge of the system becomes concentrated in a few people who can maintain it. That combination creates a control gap: the organisation inherits the risk of outdated design without always inheriting the support model needed to change it. In critical infrastructure, this is not just a technical debt issue. It becomes an availability and resilience issue when attackers can exploit outdated access paths faster than teams can retire them.

Practical implication: inventory legacy authentication dependencies and prioritise the systems where old login methods still provide broad operational reach.

Passwords, MFA, and the limits of single-factor trust

Passwords are vulnerable because they can be guessed, stolen, intercepted, or reused across systems. Once one set of credentials is compromised, the attacker often gains a foothold that can spread far beyond the original system. MFA raises the bar by requiring additional proof of identity, but it is only effective when it is deployed consistently and paired with sound policy. In environments that still depend on passwords as the primary trust signal, the real issue is not user inconvenience. It is that the organisation has built critical access on an easily copied secret.

Practical implication: replace password-first access paths with phishing-resistant MFA wherever operationally feasible, especially for privileged and remote access.

Machine identity management in operational technology environments

Machine identity management covers the certificates, keys, and trust relationships that let devices prove who they are. In manufacturing, energy, and transportation environments, this matters because one device compromise can become a network compromise if device trust is not tightly controlled. PKI gives organisations a way to authenticate devices and assert that communications are reaching a trusted endpoint. But PKI only works as a governance model when issuance, renewal, revocation, and auditing are managed as lifecycle controls, not ad hoc infrastructure tasks.

Practical implication: treat device certificates and other machine identities as governed assets with explicit issuance, revocation, and audit ownership.

Threat narrative

Attacker objective: The objective is to gain access through weak identity controls and create disruption that reaches operational systems and the populations that depend on them.

1. Entry occurred through trust in legacy access paths and older authentication methods that were still viable in critical infrastructure environments.
2. Escalation followed when a compromised or weak identity path could be used to reach systems with operational significance rather than isolated low-risk resources.
3. Impact was felt beyond the network because disruption in critical infrastructure quickly translated into broader physical and economic consequences.

Breaches seen in the wild

• Reviewdog GitHub Action supply chain attack — reviewdog/action-setup GitHub Action supply chain attack exposed secrets.
• CI/CD pipeline exploitation case study — full server takeover via exposed .git directory and mismanaged CI/CD pipeline secrets.

Read our 52 NHI Breaches Analysis report for a comprehensive view of breaches impacting Non-Human Identities including AI Agents.

NHI Mgmt Group analysis

Legacy authentication in critical infrastructure is an identity governance problem, not just a modernization problem. The article shows how outdated systems become durable attack paths when controls cannot be refreshed as quickly as the business changes. That matters across human and machine identity because the same governance failure allows old access methods to survive as exceptions long after they stop being defensible. Practitioners should treat legacy authentication as a lifecycle issue with security impact, not as a narrow infrastructure constraint.

Password reliance creates an identity blast radius that is larger than most organisations admit. Once a password is stolen or reused, one login can become many reachable systems. In critical infrastructure, that is especially dangerous because operational systems often sit close to production impact. The lesson for IAM leaders is that password-first trust is not just weak assurance, it is broad exposure that can propagate across environments.

Machine identity must be governed with the same seriousness as human access. The article’s machine and IoT discussion is a reminder that devices are not peripheral actors. Certificates, keys, issuance, and revocation define whether the organisation trusts the endpoint at all. Without that discipline, device access becomes an unmanaged path into the network. Practitioners should align machine identity ownership, not just tool deployment.

Stricter compliance is arriving because identity controls are now an operational resilience issue. The post links modernisation, regulation, and infrastructure risk in one chain. That is the right framing for regulated sectors: compliance pressure is not separate from authentication design, it is a consequence of how access failures ripple into physical and economic harm. Security teams should expect identity assurance requirements to keep rising, especially where critical services depend on trust decisions made at login.

From our research:

• 90% of IT leaders say properly managing NHIs is essential for a successful zero-trust implementation, according to Ultimate Guide to NHIs.
• Only 5.7% of organisations have full visibility into their service accounts, which shows how often machine identity ownership is still incomplete.
• For a broader governance baseline, Top 10 NHI Issues explains where visibility, rotation, and offboarding failures typically start.

What this signals

Legacy authentication is rarely a single-control failure. It is usually the point where visibility, lifecycle ownership, and operational urgency all collide. In critical infrastructure programmes, that means identity teams should assume some systems will lag modern standards and plan compensating controls around the most exposed paths, not the average case.

Machine identity governance will keep moving closer to the centre of resilience planning. The more organisations rely on connected devices, the more device certificates, revocation discipline, and auditability matter to business continuity. For teams building their programmes, the question is no longer whether to govern machine identities, but whether they can prove who owns them and how fast trust can be withdrawn.

If you are aligning identity controls with a resilience programme, the most useful starting point is lifecycle control. The pattern described here matches the same governance gaps that show up in the 52 NHI Breaches Analysis, where unmanaged credentials and weak offboarding repeatedly expand the attack surface.

For practitioners

• Retire password-only access paths Map every critical system where passwords still provide initial access and prioritise those paths for phishing-resistant MFA or equivalent stronger authentication. Focus first on administrative, remote, and operationally sensitive access where compromise would create the broadest blast radius.
• Classify machine identities as governed assets Assign explicit owners for device certificates, service certificates, and other machine credentials, then define issuance, renewal, revocation, and audit requirements. This is especially important in manufacturing, energy, transportation, and other operational environments where device trust affects production outcomes.
• Modernize legacy authentication by system criticality Rank legacy systems by business impact, exposure, and supportability, then plan modernization in the order that reduces identity risk fastest. Where full replacement is not immediate, isolate the most exposed legacy authentication paths and add compensating controls around them.
• Prepare for stronger regulatory identity baselines Use current compliance obligations as the floor, not the target, and test whether your current identity controls would satisfy a tougher future baseline. Build evidence for strong authentication, documented controls, and auditability before new requirements force a rushed response.

Key takeaways

• The Colonial Pipeline case reinforced that weak identity controls in critical infrastructure can turn authentication gaps into operational disruption.
• Password dependence and unmanaged machine identities create broad attack paths, especially where legacy systems still carry essential business functions.
• The most defensible response is to modernize authentication, govern device trust as a lifecycle asset, and plan for stricter compliance expectations.

Key terms

• Machine Identity: A machine identity is the credential set a device, workload, or connected system uses to prove it is trusted. In practice, this usually means certificates, keys, or tokens that must be issued, renewed, revoked, and audited across the full lifecycle.
• Legacy Authentication: Legacy authentication is an older login or trust method that remains in use after stronger controls have become available. It often persists because systems are hard to replace, but its continued use creates governance debt when it cannot meet current assurance expectations.
• Identity Blast Radius: Identity blast radius is the amount of damage one compromised identity can cause before access is contained. The term applies to both human and non-human identities, but the risk grows sharply when one credential can reach multiple systems or operational functions.

Deepen your knowledge

Authentication modernization and machine identity governance are core topics in our NHI Foundation Level course, the industry's only accredited NHI security programme. If you are building a resilience-oriented identity programme from a legacy starting point, it is worth exploring.

This post draws on content published by Axiad: Future-Proof Authentication and the impact of the Colonial Pipeline attack. Read the original.