TL;DR: Cloud security failures often begin with governance gaps rather than provider defects, as Google Cloud’s shared responsibility model still leaves customers accountable for overly permissive service accounts, exposed storage buckets, firewall exposure, and guest OS patching, according to Intruder. The implication for IAM and cloud teams is that least privilege, access scoping, and continuous posture visibility remain the real control boundaries.
At a glance
What this is: This guide explains where Google Cloud customer responsibility begins and shows that common exposure still comes from IAM, storage, network, and guest OS choices rather than provider defects.
Why it matters: It matters because cloud teams, IAM owners, and security architects still have to govern access scope, public exposure, and patching even when the provider handles the underlying platform.
Context
Shared responsibility in cloud security is the boundary between provider-managed controls and the customer-managed controls that determine actual exposure. In Google Cloud, that boundary shifts by service model, which means IAM, storage visibility, firewall rules, and guest OS maintenance can still become the customer’s problem even when the platform itself is secure.
The practical issue is not whether Google provides security features, but whether teams correctly assign ownership and enforce them continuously. For identity teams, the most relevant failure mode is assuming the cloud provider will compensate for over-permissioned service accounts or publicly reachable resources.
The article’s examples are typical of cloud environments where governance lags behind configuration drift. The risk is routine, not exceptional.
Key questions
Q: What breaks when service accounts have more privilege than the workload needs?
A: Excessive service-account privilege turns a single compromise into broad cloud access, because the attacker inherits the workload’s permissions instead of having to escalate. In Google Cloud environments, that means a stolen secret, compromised host, or abused pipeline can become immediate administrative control. The fix is not just rotation. It is minimum privilege, scoped roles, and ownership tied to the workload’s lifecycle.
Q: Why do public buckets and wide-open firewall rules create so much cloud risk?
A: They convert configuration choices into direct exposure. A bucket or instance that is internet reachable can be discovered and abused without exploiting the provider itself, so the risk comes from customer-owned access decisions. The issue is not only misconfiguration, but the absence of continuous control over what should remain public and what should not.
Q: How can teams tell whether shared responsibility is being governed effectively?
A: Look for explicit ownership of every layer the customer controls, evidence that privilege is scoped to the task, and continuous scanning for public exposure and patch gaps. If no one can explain who owns a control, that control is already failing in practice. Effective governance shows up as documented responsibility, not assumptions.
Q: When should cloud teams prioritise posture visibility over another point-in-time hardening review?
A: They should prioritise it whenever workloads change frequently, service accounts are used for automation, or public exposure can appear through routine configuration drift. Point-in-time reviews miss the moment when a bucket becomes public or a firewall rule opens a service. Continuous visibility is the safer control because it sees responsibility failures as they emerge.
Technical breakdown
Shared responsibility in Google Cloud is about control boundaries
Shared responsibility means the cloud provider secures the platform layers it operates, while customers secure the configurations, identities, data exposure, and operating system layers they control. In practice, the boundary differs across SaaS, PaaS, and IaaS. That makes responsibility mapping a governance task, not just a technical one. If teams assume the provider covers permissions or exposure settings, they misplace accountability and create blind spots in cloud posture management.
Practical implication: Map each Google Cloud service to the controls you own, then assign explicit ownership for IAM, exposure, and patching.
Overly permissive service accounts turn IAM into a blast-radius problem
Service accounts are non-human identities that often support automation, applications, and infrastructure tasks. When they are granted administrative roles, the compromise of the host, workload, or secret store becomes a high-impact privilege event. The problem is not the existence of the account but the mismatch between its task and its access scope. Least privilege reduces the blast radius because the attacker inherits only the minimum usable permissions instead of control of the whole project.
Practical implication: Review service account roles for task-specific scope and remove administrator permissions that are not essential.
Public storage and wide-open firewalls create avoidable exposure paths
Cloud storage buckets and firewall rules are control points that customers configure directly, even when the provider offers the mechanisms. A bucket intended for public content can be misused for sensitive data, and a compute instance with an exposed IP and permissive firewall becomes reachable from the internet whether or not anyone intended it. These are governance failures because the platform does what it was told, not what the organisation meant. Continuous discovery is needed to catch drift before it becomes reachable exposure.
Practical implication: Continuously scan for public buckets, exposed services, and permissive firewall rules across all cloud accounts.
Threat narrative
Attacker objective: The attacker’s objective is to turn routine cloud misconfiguration into direct access, broader privilege, or data exposure inside the customer’s Google Cloud environment.
- Entry occurs when an attacker finds a publicly reachable cloud resource, a misconfigured bucket, or an overprivileged service account that can be abused directly.
- Credential access or privilege abuse follows when a compromised service account token or administrator-level identity is used to expand control inside the project.
- Impact occurs when the attacker can read data, modify resources, or persist in the environment without needing additional lateral movement.
Breaches seen in the wild
- Google API Keys Exposure — Gemini AI: Google API keys exposed in client-side code via Gemini AI integrations, creating data leak risk.
Read and download The State of NHI & AI Agent Breach Report 2026, covering 200+ breaches impacting Non-Human Identities including AI Agents.
NHI Mgmt Group analysis
Shared responsibility failure is usually an identity governance failure first: the cloud provider may secure the platform, but it cannot determine whether a service account needs admin-level access or whether a bucket should be public. That judgment sits with the customer’s IAM and cloud governance programme. The operational lesson is that cloud responsibility models only work when identity scope and exposure settings are owned as continuously managed controls.
Overprivileged service accounts create a machine-identity blast radius that many cloud programmes still underestimate: when a workload identity can edit or delete resources, compromise of the runtime or stored secret becomes equivalent to project-level control. This is a classic NHI governance gap, not just a cloud hardening issue. The right mental model is that every unnecessary permission increases the fallout of one identity compromise.
Public storage and permissive network paths show why configuration is part of the control plane, not a separate hygiene layer: the shared responsibility model does not reduce risk unless teams actively govern what is internet-facing and what is internally scoped. That makes cloud posture management, IAM review, and exposure monitoring inseparable disciplines. Practitioners should treat these settings as part of identity-bound access control, not as one-off infrastructure choices.
Continuous visibility is the named concept this article reinforces: cloud exposure persists when teams rely on static ownership assumptions instead of ongoing control verification. The combination of IAM, storage, network, and guest OS responsibilities means that posture drift can emerge in any layer that customers still own. Practitioners need a governance model that checks responsibility boundaries continuously, not only at deployment time.
From our research library:
- 82% of breaches involved data stored in the cloud, according to IBM (2024).
What this signals
Shared responsibility only works when teams treat identity and exposure as live controls: a cloud provider can secure the platform, but it cannot decide whether a service account should be privileged or whether a bucket should be public. The reader takeaway is that governance has to follow configuration drift, not just initial deployment decisions.
Machine-identity governance is the cloud control boundary most teams still under-enforce: service accounts often outlive the narrow task they were created for, and that creates a permission footprint larger than the workload really needs. Security teams should align IAM review with cloud posture monitoring so that identity scope and resource exposure are assessed together.
For practitioners
- Audit service account privilege levels Identify every service account, workload identity, and automation credential with project-wide or admin access. Reduce each one to the smallest role set that still supports the task, then document why any elevated permission exists.
- Inventory public exposure paths Scan storage buckets, public IPs, and firewall rules together so that publicly reachable assets are assessed as one exposure problem rather than separate silos. Flag any resource that is internet accessible without a clear business reason.
- Separate PaaS and IaaS ownership Write down which security layers Google manages and which layers your team manages for each service model. Use that mapping to assign patching, access control, and configuration review to named owners.
- Automate guest OS patch detection For IaaS workloads, monitor missing OS and software patches continuously instead of relying on periodic manual checks. Tie alerts to asset ownership so that exposed servers cannot remain unpatched because responsibility is unclear.
- Review cloud posture continuously Use recurring scans and control checks to catch misconfigurations, overly permissive permissions, and public exposure as they appear. Treat the results as governance evidence, not just a vulnerability queue.
Key takeaways
- Cloud risk in Google Cloud still comes largely from customer-controlled identity, storage, network, and patching decisions.
- Overprivileged service accounts and public resources are governance failures because they turn ordinary configuration into direct exposure.
- Practitioners need continuous visibility, explicit ownership, and task-scoped access to keep shared responsibility from becoming shared confusion.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
OWASP Non-Human Identity Top 10 and MITRE ATT&CK address the attack and risk surface, while NIST CSF 2.0 and CIS Controls v8 set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-05 — Overprivileged NHI | The article’s service-account example is a direct overprivileged machine-identity problem. |
| NHI-06 — Insecure Cloud Deployment Configurations | Public buckets and wide-open firewall rules are cloud deployment misconfigurations. | |
| Recommendation — Reduce service account roles to the minimum required and remove administrative access that exceeds task scope. Continuously scan cloud configurations for public exposure and correct unsafe defaults before they become reachable. | ||
| NIST CSF 2.0 | PR.AA-05 — Access Permissions, Entitlements and Authorizations | The article is fundamentally about who can access what in cloud environments. |
| Recommendation — Review and constrain cloud entitlements so every identity has only the permissions its role requires. | ||
| CIS Controls v8 | CIS-5 — Account Management | Service-account governance and lifecycle ownership are central to the exposure described. |
| Recommendation — Inventory cloud accounts and service identities, then remove unused or excessively privileged access paths. | ||
| MITRE ATT&CK | TA0006;TA0008 — Credential Access; Lateral Movement | A compromised overprivileged service account enables credential abuse and expansion inside cloud environments. |
| Recommendation — Map exposed cloud identities to credential-access and lateral-movement techniques to prioritise hardening. | ||
Key terms
- Shared Responsibility Model: A shared responsibility model divides security duties between the cloud provider and the customer. For NHI governance, the provider supplies the platform controls, but the organisation still owns configuration, privilege review, secret handling, monitoring, and lifecycle management of its identities.
- Service Account: A special-purpose account used by applications, automated tools, or services rather than a human user to interact with systems, APIs, and infrastructure. Service accounts are a primary category of NHI and one of the most frequently exploited attack vectors.
- Public Exposure: The condition where a service is reachable from networks that are not trusted or tightly controlled. For identity and infrastructure teams, public exposure increases the chance that unauthenticated attackers can probe vulnerabilities directly. It is a key risk multiplier when sensitive services retain default settings or weak segmentation.
- Guest OS: The operating system running inside a virtual machine that the customer controls in an IaaS environment. The cloud provider manages the underlying hardware and host layer, but the customer is responsible for patching and securing the guest OS and its software stack.
Deepen your knowledge
NHI Foundation Level course, the industry's only accredited NHI security programme, covers NHI governance, machine identity security, and secrets management in the context of real operational control. It helps practitioners connect identity governance to cloud and automation decisions without losing sight of access scope and lifecycle risk.
Published by the NHIMG editorial team on August 19, 2026.
Updated on October 12, 2026.
NHI Mgmt Group, the independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org