Apollo Router vulnerable to Improper Check or Handling of Exceptional Conditions

Impact

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.

Patches

Router version 1.33.0 has a fix for this vulnerability. https://github.com/apollographql/router/pull/4014 fixes the issue.

Workarounds

For affected versions, avoid using the coprocessor supergraph response:

# do not use this stage in your coprocessor configuration
coprocessor:
  supergraph:
    response:

Or you can disable defer and subscriptions support:

# disable defer and subscriptions:
supergraph:
  defer_support: false # enabled by default
subscription:
  enabled: false # disabled by default

and continue to use the coprocessor supergraph response.

References

https://github.com/apollographql/router/issues/4013