GraphQL Security
Powerful queries require powerful security.
Specialized testing for GraphQL APIs including introspection attacks, query complexity abuse, and authorization bypass.
Overview
GraphQL's flexibility is both its strength and its security challenge. GraphQL Security testing addresses the unique attack surface of GraphQL APIs—introspection that reveals your entire schema, query complexity attacks that can DoS your server, and authorization models that differ fundamentally from REST. Our testers understand GraphQL architecture and test for vulnerabilities specific to this technology.
What We Test
Our graphql security engagements cover these key areas:
Introspection query exposure and schema enumeration
Query depth and complexity limits (DoS prevention)
Field-level authorization and data access controls
Batching and aliasing attacks
Mutation security and data modification controls
Subscription security and real-time data exposure
Our Approach
GraphQL testing requires specialized tools and techniques. We combine automated scanning with manual testing that understands GraphQL's query language, resolver architecture, and common implementation patterns.
Schema Discovery
Attempt introspection queries to map the complete schema. Even with introspection disabled, we use schema inference through error messages and field guessing.
Query Analysis
Analyze available queries for sensitive data access. Test field-level permissions to ensure users can only query data they're authorized to see.
Complexity Testing
Craft deeply nested and wide queries to test for denial of service through query complexity. Verify that complexity limits are properly enforced.
Authorization Testing
Test authorization at the resolver level. GraphQL's flexible queries can bypass authorization if not implemented correctly on every resolver.
Mutation Testing
Test all mutations for proper authentication, authorization, and input validation. Mutations often have weaker controls than queries.
Batching & Alias Testing
Test for vulnerabilities through request batching and query aliases that can bypass rate limiting or enable enumeration.
Common Findings
These are issues we frequently discover during graphql security engagements:
Introspection enabled in production
The GraphQL schema is fully exposed, revealing all types, queries, mutations, and their arguments. Attackers get a complete API blueprint.
Missing query complexity limits
Deeply nested queries or queries requesting many fields can exhaust server resources. A single malicious query can DoS the API.
Inconsistent authorization
Authorization checked on some resolvers but not others. Complex queries can bypass controls by accessing data through unprotected relationships.
Batching bypasses rate limits
A single HTTP request containing multiple GraphQL queries bypasses per-request rate limiting, enabling brute force and enumeration.
Alias-based enumeration
Query aliases allow multiple requests for the same field with different arguments, enabling user enumeration or password spraying in a single request.
Common Questions
Should we disable introspection?
In production, yes—or at minimum, require authentication. Introspection reveals your entire schema, making attacks easier. Keep it enabled in development, but disable or protect it in production environments.
How do you test without introspection?
We use schema inference through error messages, documentation review, client code analysis, and systematic field guessing. Real attackers do the same—disabled introspection slows them down but doesn't stop them.
Do you test subscriptions?
Yes. GraphQL subscriptions over WebSockets can expose real-time data streams. We test subscription authorization, data filtering, and connection handling.
What GraphQL servers do you have experience with?
Apollo Server, Hasura, graphql-yoga, AWS AppSync, and custom implementations. Different servers have different default configurations and common vulnerabilities.
Other API Security Testing Options
REST API Testing
Comprehensive testing of RESTful APIs for authentication bypass, injection flaws, broken object-level authorization, and data exposure.
SOAP/XML Services
Legacy web service testing for XML injection, SOAP action spoofing, and WS-Security implementation flaws.
OAuth/OIDC Assessment
Authentication flow testing for OAuth 2.0 and OpenID Connect implementations, including token handling and redirect vulnerabilities.
Mobile Backend APIs
Testing APIs that support mobile applications, focusing on certificate pinning bypass, API key exposure, and mobile-specific attack vectors.
Ready to Strengthen Your Defenses?
Schedule a free consultation with our security experts to discuss your organization's needs.
Or call us directly at (445) 273-2873