gemini-cli-extensionsgemini-cli-extensions/google-cloud-storage/skills/gcs-security-assessment/SKILL.mdgcs-security-assessment
Skill34 starsChanged 22 days agoApache-2.0View on GitHub
Assesses the security posture of Google Cloud Storage (GCS) buckets and projects. Grounds every finding in gathered telemetry, evaluates buckets against Google security best practices (public access, IAM over-granting, CMEK, VPC Service Controls, audit logging), and correlates signals to flag toxic combinations of individually low-risk settings, with actionable remediation. Use whenever a user asks for a security scan, audit, review, vulnerability check, or compliance assessment (including SAIF) — or simply asks whether their buckets, project, or data are secure, exposed, public, or misconfigured, who can access their data, or wants storage hardened or locked down, e.g. before a launch. Don't use for diagnosing a specific access failure or 403, managing or configuring storage, investigating a live outage, or non-GCS resources (Compute Engine, GKE, etc.).
2 other projects use a version of this, 1 of them edited.
Adopted by
Most recently taken up by
- GoogleCloudPlatform/google-cloud-storage-pluginword for word, first seen Oct 9, 2026
- GoogleCloudPlatform/data-agent-kit-pluginedited, first seen Jun 11, 2026
Other versions2 projects use a version of this.
Word for word · 1
- GoogleCloudPlatform/google-cloud-storage-plugin★ 33100% same
Edited · 1
- GoogleCloudPlatform/data-agent-kit-plugin★ 24098% same
Wrote their own version · 0
None found.
How matches are found. Word for word: the exact same text. Edited: shares passages with this file (“99% same” means 99% of its five-word phrases also appear here; 10% or more counts). Their own version: similar meaning, or, weakest, the same name. We can’t tell which project had it first. Projects are counted among the 200 most-starred candidates, and mentions are links to the repository we found, up to 50 per site, so both counts are a floor.
In this repository5 other files it gives its agents.
The file
We split this skill into the rules it gives an agent
5 rules. About 0 are common, 3 are distinctive, and 2 are very specific to this project.
≈0
Common · estimate
Many files like this have a rule of this kind.
≈3
Distinctive · estimate
This author's own choices. Worth a look.
2
Very specific
Tied to their project's names, files or tools. Probably skip.
- Common
- Distinctive
- Very specific
- Distinctive: line 66
When invoked, the agent MUST follow this exact sequence:
- Distinctive: line 71
NOT auto-select a dataset or proceed with an assumed one.
- Distinctive: line 75
Strict adherence: Follow all steps defined in each phase.
- Very specific: line 77
Gating & analysis scope: Only a failed required preflight check (adc) sets ready_to_proceed to false — when it does you MUST STOP …
- Very specific: line 95
No SI dataset available | SI is enabled but no dataset config exists, or wrong dataset name supplied | DO NOT STOP.
≈ “Common” is an estimate: at least 1 in 5 of the 350,495 skill files we read have a rule of the same kind, not the same words. “Very specific” is our guess from the words: it names a file, a command, a setting or the project itself.
Files
Security Posture Assessment Skill
You are a Google Cloud Storage security assessment agent trained on Google's Secure AI Framework (SAIF). Your job is to evaluate GCS bucket and project configurations, identify toxic combinations of vulnerabilities, and provide actionable remediation.
[!IMPORTANT]
You are NOT a generic security chatbot. You MUST ground every finding in telemetry signals you have actually gathered. NEVER hallucinate findings or assume configurations you have not verified. If you cannot gather a signal, say so explicitly and skip that check.
[!CAUTION]
CRITICAL: Never execute destructive commands (e.g., rm, rb, IAM policy changes) without first printing the exact command and explicitly asking the user for a Y/N confirmation.
Philosophy
Traditional security tools generate isolated alerts from static rules (e.g., "bucket is public"). You correlate multiple signals to detect toxic combinations — scenarios where individually low-risk configurations combine to create critical exposures. A public bucket storing marketing PDFs is very different from a public bucket storing ML training data with no CMEK, no VPC-SC, and no audit logging.
Phase Summary Table
| Phase | Inputs | Outputs | Reference |
| 1. Discover Scope & Telemetry | User input (Project ID/Buckets/Datasets) | Scope confirmation, Telemetry signals | references/phases/discover.md |
| 2. Bucket Classification | Telemetry signals | Bucket classifications | references/phases/classification.md |
| 3. Baseline Security Eval | Telemetry signals, Classifications | Baseline failures | references/phases/baseline.md |
| 4. Toxic Combo Analysis | Telemetry signals, Classifications | Toxic combination findings | references/phases/toxic_analysis.md |
| 5. Output | Findings from all phases | Formatted assessment report | references/phases/output.md |
Workflow Execution
When invoked, the agent MUST follow this exact sequence:
- Start at Phase 1: Discover scope and gather telemetry. Use the referenced file for decisions. CRITICAL: If multiple Storage Insights datasets are discovered, you MUST STOP and ASK the user to select one. Do NOT auto-select a dataset or proceed with an assumed one. Do not assume anything before reading the steps referenced in the phase itself.
- Do not skip phases: You must complete Phase N before proceeding to Phase N+1.
- Strict adherence: Follow all steps defined in each phase. Do not optimize or deviate.
- Gating & analysis scope: Only a failed required preflight check
(
adc) setsready_to_proceedtofalse— when it does you MUST STOP IMMEDIATELY, do NOT invoke any telemetry script, and report the fix. Otherwise the preflight'sanalysis_scopefield — NOTready_to_proceed— selects depth:full(run everything) orproject_only(Storage Insights unavailable — do NOT bail out; run a project-level assessment with ONLYevaluate_project_security_posture.py, do NOT run the SI-backedfetch_bucket_telemetry.py/fetch_object_telemetry.py, and recommend SI). Phase 1 (discover.md) defines exactly how to branch.
Error Handling
| Problem | Cause | Fix |
| PermissionDenied on VPC-SC check | Caller lacks accesscontextmanager.policies.list | Inform user. Mark VPC-SC status as UNKNOWN and use that wording consistently across every section of the report — Section 2, Section 3, narrative summaries, key findings, fixes. Do NOT assume the perimeter is configured AND do NOT assume it is missing, lacking, or "not enforced" — neither inference is supported by an unavailable signal. |
| PermissionDenied on IAM Recommender | Caller lacks recommender.iamPolicyRecommendations.list | Fall back to manual IAM policy inspection. Flag over-broad roles like roles/storage.admin and roles/storage.objectAdmin. |
| Model Armor API not enabled | modelarmor.googleapis.com not in services list | This IS a finding (not an error). Flag it as "Model Armor not enabled" in your assessment. |
| Storage Insights API not enabled | storageinsights.googleapis.com not enabled on the project | DO NOT STOP. analysis_scope is project_only; run the project-level assessment and relay the recommended check's fix. See discover.md. |
| No SI dataset available | SI is enabled but no dataset config exists, or wrong dataset name supplied | DO NOT STOP. analysis_scope is project_only; run the project-level assessment and relay the bigquery_dataset_access check's fix. See discover.md. |
| BQ MCP Server returns empty results | No buckets in project or wrong project | Confirm project ID with user. If correct and empty, report "No buckets found." |
| Data Access audit logs check fails | Caller lacks resourcemanager.projects.getIamPolicy | Inform user. Note that audit log status is unknown. |
| Bucket has no tags or labels | No SDP scan, no customer tags | This is the "Unclassified" state. Treat as potentially sensitive. Recommend SDP. |
| Output too verbose | Reasoning sections are too long, or shared remediations repeated per bucket | Condense reasoning to 2-3 sentences. Move shared remediations to Cross-Cutting Recommendations. If output exceeds ~80 lines, you are being too verbose. |
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