Improper Check for Unusual or Exceptional Conditions

Summary

The Apollo Router is a configurable, high-performance graph router written in Rust to run a federated supergraph that uses Apollo Federation. Affected versions are subject to a Denial-of-Service (DoS) type vulnerability which causes the Router to panic and terminate when a multi-part response is sent. When users send queries to the router that uses the `@defer` or Subscriptions, the Router will panic. To be vulnerable, users of Router must have a coprocessor with `coprocessor.supergraph.response` configured in their `router.yaml` and also to support either `@defer` or Subscriptions. Apollo Router version 1.33.0 has a fix for this vulnerability which was introduced in PR #4014. Users are advised to upgrade. Users unable to upgrade should avoid using the coprocessor supergraph response or disable defer and subscriptions support and continue to use the coprocessor supergraph response.