Use when assessing cloud infrastructure for security misconfigurations, IAM privilege escalation paths, S3 public exposure, open security group rules, or IaC security gaps. Covers AWS, Azure, and GCP posture assessment with MITRE ATT&CK mapping.
Installs just this skill. Get the whole plugin for auto-invocation.
⚡ How it fires
How this skill gets triggered: by you, by Claude, or both.
Fires itselfClaude auto-loads it when your prompt matches the work.
You can call itInvoke it directly when you want it.
Slash command/cloud-security
👁️ Context preview
The summary Claude sees to decide when to auto-load this skill.
Use when assessing cloud infrastructure for security misconfigurations, IAM privilege escalation paths, S3 public exposure, open security group rules, or IaC security gaps. Covers AWS, Azure, and GCP posture assessment with MITRE ATT&CK mapping.
📊 Stats
Stars23,056
Forks3,139
LanguagePython
LicenseMIT
📦 Ships with claude-skills
</> SKILL.md
cloud-security.SKILL.md
---name: "cloud-security"
description: "Use when assessing cloud infrastructure for security misconfigurations, IAM privilege escalation paths, S3 public exposure, open security group rules, or IaC security gaps. Covers AWS, Azure, and GCP posture assessment with MITRE ATT&CK mapping."
---# Cloud Security
Cloud security posture assessment skill for detecting IAM privilege escalation, public storage exposure, network configuration risks, and infrastructure-as-code misconfigurations. This is NOT incident response for active cloud compromise (see incident-response) or application vulnerability scanning (see security-pen-testing) — this is about systematic cloud configuration analysis to prevent exploitation.
---## Table of Contents
- [Overview](#overview)
- [Cloud Posture Check Tool](#cloud-posture-check-tool)
- [IAM Policy Analysis](#iam-policy-analysis)
- [S3 Exposure Assessment](#s3-exposure-assessment)
- [Security Group Analysis](#security-group-analysis)
- [IaC Security Review](#iac-security-review)
- [Cloud Provider Coverage Matrix](#cloud-provider-coverage-matrix)
- [Workflows](#workflows)
- [Anti-Patterns](#anti-patterns)
- [Cross-References](#cross-references)
---## Overview
### What This Skill Does
This skill provides the methodology and tooling for **cloud security posture management (CSPM)** — systematically checking cloud configurations for misconfigurations that create exploitable attack surface. It covers IAM privilege escalation paths, storage public exposure, network over-permissioning, and infrastructure code security.
Read access to IAM policy documents, S3 bucket configurations, and security group rules in JSON format. For continuous monitoring, integrate with cloud provider APIs (AWS Config, Azure Policy, GCP Security Command Center).
---
## Cloud Posture Check Tool
The `cloud_posture_check.py` tool runs three types of checks: `iam` (privilege escalation), `s3` (public access), and `sg` (network exposure). It auto-detects the check type from the config file structure or accepts explicit `--check` flags.
```bash
# Analyze an IAM policy for privilege escalation paths
python3 scripts/cloud_posture_check.py policy.json --check iam --json
# Assess S3 bucket configuration for public access
All four public access block settings must be enabled at both the bucket level and the AWS account level. Account-level settings can be overridden by bucket-level settings if not both enforced.
---
## Security Group Analysis
Security group analysis flags inbound rules that expose admin ports, database ports, or all traffic to internet CIDRs (0.0.0.0/0, ::/0).
### Critical Port Exposure Rules
| Port | Service | Finding Severity | Remediation |
| 1433 | MSSQL | High | Allow from application tier SG only — move to private subnet |
| 3306 | MySQL | High | Allow from application tier SG only — move to private subnet |
| 5432 | PostgreSQL | High | Allow from application tier SG only — move to private subnet |
| 27017 | MongoDB | High | Allow from application tier SG only — move to private subnet |
| 6379 | Redis | High | Allow from application tier SG only — move to private subnet |
| 9200 | Elasticsearch | High | Allow from application tier SG only — move to private subnet |
### Severity Modifiers
Use `--severity-modifier internet-facing` when the assessed resource is directly internet-accessible (load balancer, API gateway, public EC2). Use `--severity-modifier regulated-data` when the resource handles PCI, HIPAA, or GDPR-regulated data. Both modifiers bump each finding's severity by one level.
---
## IaC Security Review
Infrastructure-as-code review catches configuration issues at definition time, before deployment.
1. **Running IAM analysis without checking escalation combos** — Individual high-risk actions in isolation may appear low-risk. The danger is in combinations: `iam:PassRole` alone is not critical, but `iam:PassRole + lambda:CreateFunction` is a confirmed privilege escalation path. Always analyze the full statement, not individual actions.
2. **Enabling only bucket-level public access block** — AWS S3 has both account-level and bucket-level public access block settings. A bucket-level setting can override an account-level setting. Both must be configured. Account-level block alone is insufficient if any bucket has explicit overrides.
3. **Treating `--severity-modifier internet-facing` as optional for public resources** — Internet-facing resources have significantly higher exposure than internal resources. High findings on internet-facing infrastructure should be treated as critical. Always apply `--severity-modifier internet-facing` for DMZ, load balancer, and API gateway configurations.
4. **Checking only administrator policies** — Privilege escalation paths frequently originate from non-administrator policies that combine innocuous-looking permissions. All policies attached to production identities must be checked, not just policies with obvious elevated access.
5. **Remediating findings without root cause analysis** — Removing a dangerous permission without understanding why it was granted will result in re-addition. Document the business justification for every high-risk permission before removing it, to prevent silent re-introduction.
6. **Ignoring service account over-permissioning** — Service accounts are often over-provisioned during development and never trimmed for production. Every service account in production must be audited against AWS Access Analyzer or equivalent to identify and remove unused permissions.
7. **Not applying severity modifiers for regulated data workloads** — A high finding in a general-purpose S3 bucket is different from the same finding in a bucket containing PHI or cardholder data. Always use `--severity-modifier regulated-data` when assessing resources in regulated data environments.
| [threat-detection](../threat-detection/SKILL.md) | Cloud posture findings create hunting targets — over-permissioned roles are likely lateral movement destinations |
| [red-team](../red-team/SKILL.md) | Red team exercises specifically test exploitability of cloud misconfigurations found in posture assessment |
| [security-pen-testing](../security-pen-testing/SKILL.md) | Cloud posture findings feed into the infrastructure security section of pen test assessments |
