An attacker could use a specially crafted graphql query to execute a Distributed Denial of Service attack (DDOS attack) against a website. This mostly affects websites with publicly exposed and particularly large/complex 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 will likely further mitigate the risk.

Upgrade to silverstripe/graphql 4.2.3 or 4.1.2 or above to remedy the vulnerability.

References

• GHSA-67g8-c724-8mp3
• https://github.com/FriendsOfPHP/security-advisories/blob/master/silverstripe/graphql/CVE-2023-28104.yaml
• https://www.silverstripe.org/download/security-releases/CVE-2023-28104
• https://nvd.nist.gov/vuln/detail/CVE-2023-28104
• silverstripe/silverstripe-graphql#526
• https://github.com/silverstripe/silverstripe-graphql/releases/tag/4.1.2
• https://github.com/silverstripe/silverstripe-graphql/releases/tag/4.2.3