Cloud penetration testing simulates attacks against the resources you manage inside AWS, Azure, or Google Cloud, targeting identity, configuration, and application weaknesses rather than the provider's own infrastructure. The single most useful action is to scope tests tightly to customer-managed assets, prioritize IAM and chained misconfigurations over isolated host bugs, and follow the provider's rules of engagement to the letter. Never simulate a denial-of-service attack, and notify the provider whenever a test resembles one.
TL;DR:
- Cloud penetration tests should focus on customer-managed assets, primarily targeting identity permissions, storage configurations, and cross-account trust relationships, not the provider’s core infrastructure.
- Always confirm tests are scoped correctly, avoid DDoS simulations, and keep documentation handy to respond quickly in case of provider inquiries or suspected abuse.
- Automated tools combined with manual validation are essential to identify chained vulnerabilities, especially those involving identity misconfigurations or trust relationships.
- Regularly recheck IAM policies and storage settings after major changes to prevent configuration drift, which often reopens previously closed vulnerabilities.
- Prioritizing exploits of identity misconfigurations yields higher-impact findings than host-level vulnerabilities because attackers leverage misconfigured permissions to access large data sets.
Table of Contents
- Why cloud pentesting is different: shared responsibility and identity-centric risks
- Provider rules of engagement: what AWS, Azure and GCP typically allow and prohibit
- Practical pentest methodology: scoping, recon, vulnerability analysis, exploitation and reporting
- High-value cloud attack surfaces and typical exploitation chains
- Tools, automation and continuous posture: combining scanners and manual validation
- Nexus practitioner checklist and when to hire expert teams
- What actually moves the needle in cloud pentesting
- Cloud penetration testing support from Nexus
- Sources
- FAQ
Why cloud pentesting is different: shared responsibility and identity-centric risks
On-premises pentesting treats the network and hosts as the attack surface. Cloud environments split that surface between what the provider secures and what you configure yourself, a division known as the shared responsibility model. The provider locks down physical hardware, hypervisors, and core networking. You remain responsible for identity permissions, storage access policies, encryption keys, and workload configuration, which is exactly where most real breaches originate.
That split changes what a pentest should chase. A misconfigured IAM role or an overly permissive managed identity often opens a path to far more data than a single vulnerable host ever would, because identity in the cloud is the new perimeter.
This has practical consequences for how you run a test:
- Scope engagements around customer-managed assets only, never the provider's control plane.
- Collect evidence at each step, since cloud environments log extensively and auditors expect traceable proof.
- Treat identity chains, not individual servers, as the primary object of investigation.
Provider rules of engagement: what AWS, Azure and GCP typically allow and prohibit
Every major provider publishes a policy defining what testers can and cannot do, and violating it risks account suspension or worse. Microsoft's guidance states that Azure does not require pre-approval for testing customer-owned resources, but testers must still follow the published unified rules of engagement and avoid prohibited activities such as DDoS simulation or testing shared infrastructure. AWS similarly outlines permitted and prohibited activities in its customer support policy for penetration testing, and reviewing the current version before every engagement is worth the ten minutes it takes.
A working checklist across providers:
- Confirm the target assets are customer-owned, not shared or provider-managed services.
- Avoid any test that resembles a denial-of-service attack unless routed through an approved simulation process.
- Never attempt to break out of a managed service (a managed database, a serverless runtime) into the provider's underlying infrastructure.
- Keep written authorization, scope documents, and IP ranges on hand in case a provider abuse team makes contact.
Boundary errors happen most often when testers assume a managed service behaves like a self-hosted one and try to pivot past its edges. That single assumption is responsible for more abuse complaints than any deliberate rule violation.
Pro Tip: Keep your authorization letter, scope document, and test-account IDs in one shareable file so you can respond to a provider abuse inquiry within minutes, not hours.
Practical pentest methodology: scoping, recon, vulnerability analysis, exploitation and reporting
NIST SP 800-115 describes a structured process that still holds up in cloud contexts, provided each phase adapts to identity-centric risk.
- Scoping: define target accounts, subscriptions, and projects, and document explicit exclusions before any traffic is generated.
- Reconnaissance: enumerate exposed services, storage buckets, APIs, and identity roles using both provider APIs and external footprinting.
- Vulnerability analysis: run automated baseline checks against CIS Benchmarks, then triage findings by likely business impact.
- Exploitation: chain smaller weaknesses, such as an exposed API leading to credential exposure, to demonstrate real impact in an isolated test account.
- Reporting: deliver findings ranked by severity, with reproduction steps and remediation guidance tied to owners.
Prioritize findings using CVSS v3.1 scoring alongside the CISA Known Exploited Vulnerabilities catalogue and the asset's actual business exposure. A medium-severity storage misconfiguration on a production database matters more than a high-severity bug on an idle test instance. Automated CIS checks catch drift quickly; manual chaining is what proves whether a weakness is theoretical or exploitable.
High-value cloud attack surfaces and typical exploitation chains
Cloud breaches rarely start with a dramatic exploit. They start with a small misconfiguration that a tester, or an attacker, chains into something bigger. MITRE ATT&CK for Cloud is commonly used to map these chains and the detection coverage around them.
- Identity abuse: over-permissive IAM roles, cross-account trust relationships, and stolen instance profile or managed identity credentials are consistently among the highest-impact findings.
- SSRF to metadata theft: a server-side request forgery flaw that reaches the instance metadata service can hand an attacker temporary credentials scoped to the whole role.
- Storage misconfiguration: publicly readable or writable buckets remain a common source of exposure, often discovered only after data has already leaked.
- Exposed APIs: unauthenticated or weakly authenticated endpoints give attackers a direct line into application logic.
- Container and Kubernetes breakouts: misconfigured pod security policies or exposed kubelet APIs can let an attacker move from a container to the underlying node.
- Serverless weaknesses: overly broad function permissions or unvalidated event sources turn a small function into a privilege escalation path.
Testing trust relationships between accounts, and the identities that span them, tends to produce the highest-yield findings compared with classic host-level exploits.
Tools, automation and continuous posture: combining scanners and manual validation
No single tool covers the whole cloud attack surface, so a workable programme combines several categories with manual validation layered on top.
- Asset discovery: cloud-native inventory tools and external attack surface scanners to map what actually exists.
- IAM assessment: policy analyzers that flag excessive permissions, unused roles, and risky trust relationships.
- Configuration checks: automated scans against CIS Benchmarks to catch drift between deployments.
- DAST and API testing: dynamic scanners aimed at web applications and exposed API endpoints.
- Container and Kubernetes scanners: image and cluster scanning tools that catch privilege and network policy issues.
- Manual exploitation frameworks: used by experienced testers to chain findings and prove real-world impact.
Map automated results directly to CIS control numbers so remediation owners know exactly what to fix, then reserve manual testing time for chaining the findings automation cannot connect on its own. Run tests from sandboxed accounts, respect provider rate limits, and keep logging enabled throughout so every action can be reconstructed later.
Nexus practitioner checklist and when to hire expert teams
A short pre-engagement checklist keeps a cloud pentest safe and useful:
- Confirm written scope approval covering every account, subscription, or project in play.
- Provision least-privilege test accounts rather than reusing production credentials.
- Enable logging and alerts before testing begins, not after.
- Prepare a rollback plan for any change made during exploitation.
- Set up a communication channel with the provider in case a test resembles a prohibited activity.
Internal teams can run this checklist for straightforward single-account environments. Complex cross-account trust relationships, production systems with regulatory exposure, or multi-cloud footprints usually call for a managed engagement with practitioners who test these patterns routinely. Training such as SANS SEC588 and the GIAC Cloud Penetration Tester certification validates the identity-attack and container-testing skills this work demands. Continuous testing, rather than an annual snapshot, is what actually keeps pace with how fast cloud configurations drift.
Pro Tip: Re-run your IAM and storage checks after every significant deployment, not just on a fixed annual schedule. Configuration drift, not new vulnerabilities, is what usually reopens closed findings.
What actually moves the needle in cloud pentesting
Most cloud pentest reports still read like network pentest reports with cloud logos pasted on top: a list of open ports, a few outdated packages, a CVSS score per line. That misses where the real risk sits. The identity layer, not the host layer, is where cloud environments fail, and a report that does not walk through at least one full attack chain from initial foothold to privilege escalation has not actually tested the environment that matters.
The conventional advice to "run a scanner and check the CIS Benchmarks" is necessary but nowhere near sufficient. Automated checks catch drift, they do not catch the trust relationship between a forgotten cross-account role and a production data store. If you take one thing from this guide, prioritize identity chaining over vulnerability counting. A dozen medium-severity findings that chain into one exploitable path matter more than a single high-severity finding in isolation, and most remediation budgets are still spent the other way round.
— Nick - Sr. Executive
Cloud penetration testing support from Nexus
Nexus maps cloud pentesting engagements to the assets that actually carry risk: IAM configurations, storage policies, container and serverless workloads, and cross-account trust relationships, rather than a generic checklist. Engagements run through certified senior practitioners rather than generalists, with findings prioritized by real business impact and delivered alongside a remediation plan your team can act on immediately. If continuous posture monitoring makes more sense than a single engagement, that option sits under the same cybersecurity and cloud services catalogue. Reach out through that page to scope an engagement.
Sources
NIST SP 800-115 for methodology, Microsoft's Azure pentesting rules and AWS's pentesting policy for provider ROE, MITRE ATT&CK for Cloud for attack mapping, and CIS Benchmarks for baseline hardening. SANS SEC588 covers practitioner skills for identity and container testing.
- MITRE ATT&CK for cloud: a practitioner’s guide to detection coverage
- Penetration testing | Microsoft Learn
- NIST Special Publication 800-115
FAQ
Do I need provider approval before running a cloud pentest?
It depends on the provider and the assets involved. Azure does not require pre-approval for testing customer-owned resources as long as you follow the published rules of engagement, while AWS publishes its own permitted and prohibited activities that you should confirm before testing.
Can I simulate a DDoS attack during a cloud pentest?
No, DDoS simulation is prohibited on customer resources under Microsoft's unified rules of engagement and under equivalent AWS policy. If you need to test resilience against volumetric attacks, use a provider-approved simulation partner or a formal simulated-event process instead.
Which cloud misconfigurations should I prioritize first?
Identity issues, such as over-permissive IAM roles and cross-account trust relationships, tend to produce the highest-impact findings in cloud environments, often ahead of single-host vulnerabilities. Storage bucket exposure and metadata service abuse follow closely behind.
How often should cloud environments be pentested?
There is no universal schedule, but a hybrid approach works well: automated CIS Benchmark checks running continuously, paired with periodic manual engagements to catch chained attack paths that scanners miss. Testing after major deployments or architecture changes catches drift before it becomes exploitable.
What is the difference between testing IaaS, PaaS and SaaS environments?
IaaS testing usually covers virtual machines, networking, and storage configuration you control directly. PaaS testing focuses on application configuration and identity permissions layered on top of a managed runtime, while SaaS testing is largely limited to your own data, users, and integration settings since the provider manages the underlying platform.