Denial of service vulnerability in silverstripe-graphql via recursive queries

silverstripe-graphql is a package which serves Silverstripe data in GraphQL representations. An attacker could use a recursive graphql query to execute a Distributed Denial of Service attack (DDOS attack) against a website. This mostly affects websites with publicly exposed graphql schemas. If your Silverstripe CMS project does not expose a public facing graphql schema, a user account is required to trigger the DDOS attack. If your site is hosted behind a content delivery network (CDN), such as Imperva or CloudFlare, this may further mitigate the risk. This issue has been addressed in versions 3.8.2, 4.1.3, 4.2.5, 4.3.4, and 5.0.3. Users are advised to upgrade. There are no known workarounds for this vulnerability.