For organizations of any size and industry, safeguarding cloud infrastructure is mission critical. Although Google Cloud Platform (GCP) does provide some built-in security measures, the complexity of interconnected services—-as well as the highly customizable nature of setup—-bring added risk. Multiple high-profile security breaches in recent years have resulted from cloud misconfigurations, highlighting the need for a proactive cloud security stance—especially in expansive environments.
In addition, Google’s shared responsibility model puts the burden of securing network infrastructure and data security squarely on the customer. Penetration testing (pentesting) is a critical tool for identifying vulnerabilities and mitigating risks due to access control issues, unsecured APIs, and misconfigurations.
In this guide, we’ll cover what you need to know about GCP pentesting to keep your cloud infrastructure secure and meet your regulatory obligations:
Effective GCP pentesting combines standard pentesting methodologies with a focus on cloud-native risks. While the approach is similar to how testing is performed on environments from other major cloud providers, including AWS and Azure, each platform has its own unique characteristics, policies, and tools that dictate the exact methodology.
For GCP users, the flexibility and customizability that make it so popular also increase the attack surface. This means pentesting is essential for identifying vulnerabilities and access pathways that result from how your specific GCP instance is configured and deployed.
Traditional on-premises pentesting focuses on network perimeters, physical servers, and independent applications, with the primary goal being to prevent breaches. In contrast, GCP pentesting is centered entirely on the customer's side of the shared responsibility model—that is, the services and assets that are under your control.
For cloud environments, it’s important to use an assumed breach model, rather than simulating an external attacker trying to break through the perimeter. We simulate an attacker who has already gained initial access—for example, through a stolen user credential or compromised application—and reveal how far that access can go, so we can take steps to mitigate risk.
Acting from the assumption that a breach is possible enables a more complete cloud security assessment, allowing organizations to test their internal security controls and defenses to identify weaknesses. By revealing critical attack paths and vulnerabilities within the network, and can be exploited for privilege escalation or data exfiltration, GCP pentesting uncovers a broad range of security risks in increasingly complex cloud environments.
Pentesting policies are governed by Google’s shared responsibility model, which they call shared fate. This model entails a partnership where security duties are divided between Google and its customers. Google policies also specify what you are and aren’t allowed to test on GCP.
Google is responsible for securing the underlying cloud infrastructure of its platform. To help customers uphold their side of the partnership, Google provides in-depth guidance for security best practices. This includes recommendations for designing, deploying, and operating cloud workloads that align with your own security, privacy, and compliance needs.
Google also offers secured, attested infrastructure code that customers can use to deploy workloads securely. And when necessary, they release solutions that combine various Google Cloud services to solve complex security issues.
GCP customers are responsible for understanding their company’s security and compliance requirements, and identifying the security controls that must be configured in Google Cloud to protect confidential data and workloads.
In deciding which security controls to implement, Google recommends factoring in your compliance obligations for your industry and location, your organization’s security standards and risk management plan, and any other security requirements you’re bound to uphold for your end customers and vendors.
Responsibilities are defined by the type of workload you’re running and the cloud services you need—for example, IaaS, PaaS, SaaS, FaaS—as well as by your industry and regulatory framework, and your location. European-based businesses, for example, must meet GDPR requirements, while California-based companies are subject to the California Consumer Privacy Act (CCPA) and the California Privacy Rights Act (CPRA). Ensuring that your GCP deployments meet industry-specific regulations like HIPAA or PCI DSS is another key benefit of security testing.
Although Google does not require pre-approval, all pentesting must be in compliance with Google’s Acceptable Use Policy. This dictates that you can only conduct pentesting on your own assets and resources, including buckets, functions, Compute Engine instances, and GKE clusters. Any pentesting that disrupts service availability or impacts other tenants, such as testing vulnerabilities on shared infrastructure, is strictly forbidden.
Access controls (IAM): Ensure permissions and roles are correctly configured by performing:
Data encryption: Verify that data is properly encrypted in transit and at rest by:
Network security: Check firewall rules and other network settings by:
According to a Google Cloud report, compromised credentials account for over 60% of security breaches, highlighting how critical and effective automated secret scanning can be.
Combe wholly automated vulnerability assessment with pentesting that involves both automated and manual methods to identify and exploit vulnerabilities, and create a more robust approach to uncovering issues.
Optimal GCP pentesting methodology is designed to identify and exploit misconfigurations, weak identity access management (IAM ) policies, and architectural exposures across GCP environments. Testing spans reconnaissance, identity compromise, application layer abuse, and lateral movement using native GCP features and APIs.
Some guidelines to follow are below.
The shared responsibility model is the foundational principle for all cloud penetration testing. You are responsible for securing your specific cloud resources—not the underlying infrastructure. That’s Google’s domain.
A pentest should only focus on your configurations, data, and applications. Cleaning up your side of the model includes:
Instead of a simple checklist, modern GCP pentests simulate the tactics of a real-world attacker. This approach goes beyond automated scans to find complex, chained vulnerabilities that human attackers look to exploit. Tests are often objective-focused, with a specific goal. Common objectives include:
Cloud environments introduce new types of vulnerabilities that don't exist in traditional on-premise networks. Key areas of focus for GCP pentesting include:
A good penetration test doesn't stop at finding vulnerabilities—it provides a clear roadmap for fixing them. Detailed reporting helps organizations understand not just what's wrong, but how to correct it and improve their overall security posture.
The final report should detail the findings and include:
Conducting regular, comprehensive GCP pentesting is essential to maintaining cloud infrastructure security and data privacy within your specific GCP setup. A systematic approach that follows best practices and methodologies within Google’s shared responsibility framework will help you safeguard sensitive information, meet regulatory obligations, and improve your security posture.
Cloud security services by Cobalt gives you access to a team of 450+ pentesting experts, with a wide range of hands-on experience and specialized knowledge. Start testing quickly with our user-friendly platform and achieve measurable risk reduction—faster and at lower cost than traditional pentesting. To discuss your cloud security needs and learn more about how we can help secure your GCP cloud infrastructure with comprehensive pentesting, contact us today.