GraphQL Attack Surface & Reconnaissance

GraphQL creates a flexible interface layer over your data. Unlike REST, which exposes multiple endpoints (e.g., `/users`, `/products`), GraphQL typically exposes a single endpoint (usually `/graphql`) that accepts complex queries.

This architectural shift moves control from the server to the client. While this improves developer experience, it creates a massive attack surface where a single endpoint must validate an infinite number of possible query combinations.

The attack surface is defined by the Schema. Every type, field, and argument defined in your schema is a potential entry point for an attacker.

Before launching an attack, a threat actor performs reconnaissance to map the schema. This is often trivial because many production environments leave Introspection enabled.

Introspection Queries: GraphQL has a built-in system that allows clients to ask the server for its own schema. By querying `__schema`, an attacker receives a complete map of all available data, including hidden admin fields and deprecated arguments.

Even if introspection is disabled, attackers use Field Suggestion Analysis. By sending queries with typos, the verbose error messages ("Did you mean 'password'?") can reveal the existence of hidden fields.

In enterprise environments, GraphQL often acts as a gateway to multiple microservices. A misconfiguration here creates a "Super-Graph" vulnerability.

• Lack of Visibility: Traditional WAFs inspecting URL paths miss malicious payloads buried inside the GraphQL query body.
• Authorization Gaps: Developers often secure the top-level Query resolver but forget to check permissions on nested field resolvers.