What do security teams get wrong about least privilege and multi-factor authentication in modern attack paths?

Why Security Teams Misread Least Privilege and MFA

least privilege and MFA are often treated as if they end the risk conversation, but modern attack paths do not respect that assumption. Attackers chain phishing, token theft, OAuth abuse, and lateral movement until a valid identity is used in an unexpected way. That is why NHI Management Group research repeatedly frames identity as an attack surface, not a one-time control decision, including findings in The State of Non-Human Identity Security and the 52 NHI Breaches Analysis.

The main mistake is confusing control presence with control effectiveness. MFA can be bypassed through session theft, push fatigue, adversary-in-the-middle tactics, or recovery flows that are less protected than the primary login. Least privilege can also drift when service accounts, API tokens, delegated access, or cloud roles accumulate over time. Current guidance from CISA cyber threat advisories and NIST SP 800-53 Rev 5 Security and Privacy Controls supports continuous validation, not checkbox compliance. In practice, many security teams discover these failures only after a valid account has already been used to move laterally or access a sensitive system.

How Least Privilege and MFA Fail in Real Attack Paths

Effective defence starts by treating identity as dynamic. An access policy that was appropriate at onboarding may be wrong an hour later if a user, workload, or agent has shifted tasks, context, or trust zone. Attack paths often begin with a legitimate login, then pivot through a trusted session, a mis-scoped role, or a privileged integration. The security question is not whether MFA exists, but whether it still constrains the action being attempted at that moment.

For human identities, this means tightening role scope, requiring phishing-resistant MFA where possible, and monitoring for anomalous privilege use. For NHIs and software workloads, the same logic is stronger: short-lived credentials, explicit workload identity, and runtime policy checks matter more than static permissions. NHI Management Group’s OWASP NHI Top 10 and the industry survey in The 2026 Infrastructure Identity Survey show why over-privilege and static credentials remain persistent failure modes.

• Use phishing-resistant MFA for interactive access, but assume tokens and sessions can still be stolen.
• Reduce standing privilege and issue time-bound access only when a task actually needs it.
• Monitor identity behaviour, not just authentication success, because valid logins can still be malicious.
• Apply runtime authorisation for high-risk actions instead of relying on initial login trust.

Standards such as OWASP Non-Human Identity Top 10 and NIST SP 800-207 Zero Trust Architecture reinforce the same operational pattern: verify every request, limit every entitlement, and assume the identity can be repurposed. These controls tend to break down when long-lived service accounts and legacy SSO flows are still allowed to inherit broad trust because the environment cannot enforce short-lived, context-aware decisions.

Where the Usual Guidance Breaks Down

Tighter privilege and stronger MFA often increase operational overhead, so organisations must balance friction against actual risk reduction. That tradeoff becomes visible in environments with brittle legacy applications, shared admin accounts, or vendor integrations that cannot support modern authentication. Best practice is evolving, but there is no universal standard for every edge case yet.

One common exception is service-to-service access. A human-style MFA requirement does not solve credential replay for automation, and it can even create a false sense of safety if the underlying secret never rotates. Another edge case is privileged recovery: if help desk resets, backup codes, or break-glass accounts are weaker than normal access, attackers will target them first. The real control objective is to make the weakest path into the environment as measurable and short-lived as the strongest one.

For that reason, security teams should review whether least privilege is enforced at the token, session, role, and workload layers, not just at the user directory. The same applies to agentic and autonomous systems, where current research from The State of Non-Human Identity Security shows how quickly visibility and control erode once identities are shared, delegated, or embedded in workflows. The practical lesson is simple: if privilege can persist beyond the moment it is needed, attackers will eventually find that path.

Related resources from NHI Mgmt Group

• What do security teams get wrong about multi-factor authentication in browser-based login flows?
• What do security teams get wrong about multi-factor authentication and rainbow table attacks?
• What do security teams get wrong about least privilege for autonomous systems?
• What do security teams get wrong about least privilege for agentic systems?