/cloud-security

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.

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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)

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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.

Distinction from Other Security Skills

| Skill | Focus | Approach | |-------|-------|----------| | **cloud-security** (this) | Cloud configuration risk | Preventive — assess before exploitation | | incident-response | Active cloud incidents | Reactive — triage confirmed cloud compromise | | threat-detection | Behavioral anomalies | Proactive — hunt for attacker activity in cloud logs | | security-pen-testing | Application vulnerabilities | Offensive — actively exploit found weaknesses |

Prerequisites

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).

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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.

# 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
python3 scripts/cloud_posture_check.py bucket_config.json --check s3 --json

# Check security group rules for open admin ports
python3 scripts/cloud_posture_check.py sg.json --check sg --json

# Run all checks with internet-facing severity bump
python3 scripts/cloud_posture_check.py config.json --check all \
  --provider aws --severity-modifier internet-facing --json

# Regulated data context (bumps severity by one level for all findings)
python3 scripts/cloud_posture_check.py config.json --check all \
  --severity-modifier regulated-data --json

# Pipe IAM policy from AWS CLI
aws iam get-policy-version --policy-arn arn:aws:iam::123456789012:policy/MyPolicy \
  --version-id v1 | jq '.PolicyVersion.Document' | \
  python3 scripts/cloud_posture_check.py - --check iam --json

Exit Codes

| Code | Meaning | Required Action | |------|---------|-----------------| | 0 | No high/critical findings | No action required | | 1 | High-severity findings | Remediate within 24 hours | | 2 | Critical findings | Remediate immediately — escalate to incident-response if active |

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IAM Policy Analysis

IAM analysis detects privilege escalation paths, overprivileged grants, public principal exposure, and data exfiltration risk.

Privilege Escalation Patterns

| Pattern | Severity | Key Action Combination | MITRE | |---------|----------|------------------------|-------| | Lambda PassRole escalation | Critical | iam:PassRole + lambda:CreateFunction | T1078.004 | | EC2 instance profile abuse | Critical | iam:PassRole + ec2:RunInstances | T1078.004 | | CloudFormation PassRole | Critical | iam:PassRole + cloudformation:CreateStack | T1078.004 | | Self-attach policy escalation | Critical | iam:AttachUserPolicy + sts:GetCallerIdentity | T1484.001 | | Inline policy self-escalation | Critical | iam:PutUserPolicy + sts:GetCallerIdentity | T1484.001 | | Policy version backdoor | Critical | iam:CreatePolicyVersion + iam:ListPolicies | T1484.001 | | Credential harvesting | High | iam:CreateAccessKey + iam:ListUsers | T1098.001 | | Group membership escalation | High | iam:AddUserToGroup + iam:ListGroups | T1098 | | Password reset attack | High | iam:UpdateLoginProfile + iam:ListUsers | T1098 | | Service-level wildcard | High | iam:* or s3:* or ec2:* | T1078.004 |

IAM Finding Severity Guide

| Finding Type | Condition | Severity | |-------------|-----------|----------| | Full admin wildcard | Action=* Resource=* | Critical | | Public principal | Principal: '*' | Critical | | Dangerous action combo | Two-action escalation path | Critical | | Individual priv-esc actions | On wildcard resource | High | | Data exfiltration actions | s3:GetObject, secretsmanager:GetSecretValue on * | High | | Service wildcard | service:* action | High | | Data actions on named resource | Appropriate scope | Low/Clean |

Least Privilege Recommendations

For every critical or high finding, the tool outputs a `least_privilege_suggestion` field with specific remediation guidance:

• Replace `Action: *` with a named list of required actions
• Replace `Resource: *` with specific ARN patterns
• Use AWS Access Analyzer to identify actually-used permissions
• Separate dangerous action combinations into di