# Florianbuetow Claude Code GRAPHQL > GraphQL Security (GQL) - Skill: `tomevault-io/florianbuetow-claude-code-graphql` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/florianbuetow-claude-code-graphql` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/florianbuetow-claude-code-graphql/raw - Safety review: pending (external: skill-scanner PASS, skillspector PASS) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Security - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/florianbuetow-claude-code-graphql --- # GraphQL Security (GQL) Analyze GraphQL APIs for security vulnerabilities including introspection enabled in production, missing query depth limits, no complexity analysis, batching abuse, alias-based denial of service, and missing per-field authorization. GraphQL's flexibility makes it a rich attack surface when default configurations are deployed to production without hardening. ## Supported Flags Read `../../shared/schemas/flags.md` for the full flag specification. This skill supports all cross-cutting flags. Key flags for this skill: - `--scope` determines which files to analyze (default: `changed`) - `--depth standard` reads code and checks GraphQL configuration - `--depth deep` traces resolvers to data sources and maps authorization coverage - `--severity` filters output (GraphQL issues range from `medium` to `critical`) ## Framework Context Key CWEs in scope: - CWE-200: Exposure of Sensitive Information (introspection) - CWE-400: Uncontrolled Resource Consumption (depth/complexity) - CWE-862: Missing Authorization (per-field auth) - CWE-770: Allocation of Resources Without Limits (batching) - CWE-284: Improper Access Control ## Detection Patterns Read `references/detection-patterns.md` for the full catalog of code patterns, search heuristics, language-specific examples, and false positive guidance. ## Workflow ### 1. Determine Scope Parse flags and resolve the file list per `../../shared/schemas/flags.md`. Filter to files likely to contain GraphQL logic: - Schema definitions (`**/*.graphql`, `**/schema.*`, `**/typeDefs*`) - Resolver implementations (`**/resolvers/**`, `**/graphql/**`) - GraphQL server configuration (`**/server.*`, `**/app.*`, `**/index.*`) - Middleware and plugins (`**/middleware/**`, `**/plugins/**`) - Authorization directives (`**/directives/**`, `**/guards/**`) ### 2. Check for Available Scanners Detect scanners per `../../shared/schemas/scanners.md`: 1. `semgrep` -- primary scanner for GraphQL patterns 2. `graphql-cop` -- specialized GraphQL security auditor (if available) Record which scanners are available and which are missing. ### 3. Run Scanners (If Available) If semgrep is available, run with rules targeting GraphQL: ``` semgrep scan --config auto --json --quiet ``` Filter results to rules matching GraphQL security patterns. Normalize output to the findings schema. ### 4. Claude Code Analysis Regardless of scanner availability, perform manual code analysis: 1. **Introspection check**: Find GraphQL server configuration and verify introspection is disabled in production environments. 2. **Depth limiting**: Check for depth limiting middleware (graphql-depth-limit, @graphql-tools/utils, custom validation rules). 3. **Complexity analysis**: Verify query complexity is calculated and limited before execution (graphql-query-complexity, cost analysis). 4. **Batching controls**: Check whether query batching is enabled and if there are limits on the number of operations per request. 5. **Alias abuse**: Verify aliases are counted toward rate limiting and complexity calculations. 6. **Per-field authorization**: Trace resolvers for sensitive fields and verify each checks the requesting user's permissions. When `--depth deep`, additionally trace: - Full resolver chain from query to data source - Authorization directive/guard coverage across all types and fields - Subscription authentication and authorization ### 5. Report Findings Format output per `../../shared/schemas/findings.md` using the `GQL` prefix (e.g., `GQL-001`, `GQL-002`). Include for each finding: - Severity and confidence - Exact file location with code snippet - Exploit scenario (example malicious query when applicable) - Concrete fix with diff when possible - CWE references ## What to Look For These are the high-signal patterns specific to GraphQL security. Each maps to a detection pattern in `references/detection-patterns.md`. 1. **Introspection enabled in production** -- `__schema` and `__type` queries are accessible, revealing the entire API schema to attackers. 2. **No query depth limit** -- Deeply nested queries can exhaust server resources (e.g., `user { friends { friends { friends { ... } } } }`). 3. **No query complexity limit** -- Expensive queries with many fields or computed values can cause denial of service. 4. **Batching abuse** -- Multiple queries in a single request bypass per-request rate limiting and can brute-force authentication. 5. **Alias-based denial of service** -- Using aliases to repeat expensive fields/resolvers many times in a single query. 6. **Missing per-field authorization** -- Sensitive fields (email, SSN, balance) exposed to any authenticated user without field-level access checks. ## Scanner Integration | Scanner | Coverage | Command | |---------|----------|---------| | semgrep | Introspection, missing auth directives | `semgrep scan --config auto --json --quiet ` | | graphql-cop | Introspection, depth, batching, aliases | `graphql-cop -t ` | **Fallback (no scanner)**: Use Grep with patterns from `references/detection-patterns.md` to find GraphQL server configuration, depth/complexity middleware, resolver authorization, and batching settings. Report findings with `confidence: medium`. ## Output Format Use the findings schema from `../../shared/schemas/findings.md`. - **ID prefix**: `GQL` (e.g., `GQL-001`) - **metadata.tool**: `graphql` - **metadata.framework**: `specialized` - **metadata.category**: `GQL` - **references.cwe**: `CWE-200`, `CWE-400`, `CWE-862` - **references.owasp**: `A05:2021` (Security Misconfiguration) - **references.stride**: `I` (Information Disclosure) or `D` (Denial of Service) Severity guidance for this category: - **critical**: Missing per-field auth on sensitive data, introspection exposing internal schemas - **high**: No depth or complexity limits, batching with no limits on auth endpoints - **medium**: Introspection enabled in prod (non-sensitive schema), alias abuse possible - **low**: Overly permissive but rate-limited batching, minor information disclosure --- > Converted and distributed by [TomeVault](https://tomevault.io/claim/florianbuetow) — claim your Tome and manage your conversions.