Grackle has StackOverflowError in GraphQL query processing

Impact

Prior to this fix, the GraphQL query parsing was vulnerable to StackOverflowErrors. The possibility of small queries resulting in stack overflow is a potential denial of service vulnerability.

This potentially affects all applications using Grackle which have untrusted users.

[!CAUTION]
No specific knowledge of an application's GraphQL schema would be required to construct a pathological query.

Patches

The stack overflow issues have been resolved in the v0.18.0 release of Grackle.

Workarounds

Users could interpose a sanitizing layer in between untrusted input and Grackle query processing.