SvelteKit Denial of service and possible SSRF when using prerendering

Vulnerability Description

SvelteKit is a framework for rapidly developing robust, performant web applications using Svelte. Prior to 2.49.5, SvelteKit is vulnerable to a server side request forgery (SSRF) and denial of service (DoS) under certain conditions. From 2.44.0 through 2.49.4, the vulnerability results in a DoS when your app has at least one prerendered route (export const prerender = true). From 2.19.0 through 2.49.4, the vulnerability results in a DoS when your app has at least one prerendered route and you are using adapter-node without a configured ORIGIN environment variable, and you are not using a reverse proxy that implements Host header validation. This vulnerability is fixed in 2.49.5.

References

• https://github.com/sveltejs/kit/security/advisories/GHSA-j62c-4x62-9r35
• https://github.com/sveltejs/kit/commit/d9ae9b00b14f5574d109f3fd548f960594346226