Why do traditional VPNs and private circuits create cost and security risk for distributed organisations?

Traditional VPNs and private circuits create risk because they centralise trust, expand network reach more than most teams need, and are costly to maintain at scale. In distributed environments, that model slows change, complicates support for remote sites, and increases the blast radius of access. A cloud-native zero trust model reduces those issues by narrowing connectivity to specific applications and paths.

Why centralized VPN and circuit models become expensive at distributed scale

Traditional VPNs and private circuits were built for a world where users and sites were easier to anchor to a few trusted network edges. In distributed organisations, every new branch, remote worker, contractor, or cloud workload adds more tunnels, more appliances, more routing complexity, and more support burden. The cost grows not just in licensing and bandwidth, but in operational drag, change management, and troubleshooting time.

Private circuits also tend to lock teams into fixed capacity and long provisioning cycles, which makes them a poor fit for organisations that open, close, or reconfigure sites frequently. When the network has to be extended everywhere, the infrastructure becomes the product. That is why modern secure remote access guidance increasingly favors application-level access over broad network reach, as described in NIST SP 800-207 Zero Trust Architecture and Remote Access Identity Guide.

From a practitioner perspective, the hidden cost is supportability. The more users depend on a shared access fabric, the harder it becomes to isolate faults, onboard new locations, and keep latency acceptable for business-critical applications.

Why the security model creates more exposure than most teams intend

The main security problem is that traditional VPNs concentrate trust in a few ingress points and then grant broad reach once a session is established. That makes the perimeter device, the remote-access account, and the tunnel path high-value targets. If any of those are weak, compromised, or misconfigured, an attacker can often move far beyond the original access need.

This is why stolen credentials and overbroad access are such a common failure mode for remote access. A compromise of a VPN account can become an enterprise-wide foothold instead of a narrowly scoped application session, as seen in SonicWall VPN Mass Breach via Stolen Credentials. The control goal in a modern design is to reduce reach, verify continuously, and restrict access to the specific application or path actually needed.

That is also why distributed organisations often pair zero trust access with MFA, device posture checks, and tighter segmentation. The security gain comes from limiting lateral movement, shrinking blast radius, and removing the assumption that network location equals trust.

What changes when access is tied to application need instead of network reach

Cloud-native zero trust changes the design from “connect to the network, then find the resource” to “prove the request, then permit only the resource.” That shift matters because it turns access into a bounded decision rather than a standing network relationship. For distributed organisations, this usually improves both security and agility: new sites and users can be brought online without extending the internal network in the old style.

It also improves governance. When access is scoped to a specific application or service, teams can review who reaches what, retire dormant access faster, and reduce the number of implicit trust paths that need to be maintained. The practical pattern is to replace broad connectivity with narrowly granted, policy-driven access paths, which is the core model in NIST SP 800-207 Zero Trust Architecture.

For remote and hybrid environments, the useful question is not whether a VPN exists, but whether it is still the right control boundary for each application and user population. In many organisations, it is only appropriate for a shrinking set of legacy cases.

Risk and Threat Considerations

When VPNs or private circuits become the default access layer, the organisation inherits a larger trust surface than necessary. That increases exposure to credential theft, device compromise, misrouted access, and lateral movement, especially when the same path serves many users, sites, or third parties.

Failure mechanism: A single compromised remote-access account or perimeter device can provide broad internal reach because the model authenticates entry once and then trusts the session too widely.

Impact: Attackers can expand from initial access into discovery, privilege escalation, and internal movement, while defenders also face higher blast-radius and recovery costs after a breach or misconfiguration.

Standards & Framework Alignment

This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.

NIST SP 800-53 Rev 5, NIST Zero Trust (SP 800-207), CIS Controls v8 and NIST CSF 2.0 set the technical controls, while ISO/IEC 27001:2022 defines the regulatory obligations.

Framework	Control / Reference	Relevance
NIST SP 800-53 Rev 5	AC-4 — Information Flow Enforcement	Limits remote access paths to approved flows and destinations.
Recommendation — Enforce approved flows so remote users reach only required resources.
NIST Zero Trust (SP 800-207)	N/A — Zero Trust Architecture	Directly addresses replacing implicit network trust with verified, least-privilege access.
Recommendation — Apply zero trust principles to narrow access to specific applications and sessions.
CIS Controls v8	CIS-6 — Access Control Management	Supports tightening and reviewing remote access and privileged pathways.
Recommendation — Review and remove unnecessary remote-access paths and standing permissions.
ISO/IEC 27001:2022	A.5.15 — Access control	Requires controlled access rules for remote connectivity and internal resources.
Recommendation — Define and enforce access rules that limit remote connectivity to business need.
NIST CSF 2.0	PR.AA-05 — Network Segmentation	Directly supports reducing blast radius from broad VPN connectivity.
Recommendation — Segment access so a remote session cannot reach everything by default.

Practitioner Guidance

What to prioritise: Identify which access paths still need network-level tunneling and which can move to application-scoped access. If an application does not truly require broad subnet reach, treat that as a candidate for zero trust migration rather than another VPN exception.

What to verify: Validate that remote access decisions are tied to user, device, and application context, not just a successful login. Also verify that dormant VPN accounts, standing third-party access, and overly permissive routes are being reviewed as part of the same control set.

Common mistake: Treating VPN modernization as a transport refresh instead of a trust-boundary redesign. If the new design still gives broad network reach after authentication, the organisation has kept much of the cost and most of the risk.

Practitioner takeaway: The goal is not to eliminate every remote-access control, but to remove unnecessary network trust and reserve broad connectivity only for cases that genuinely need it.