Insecure Inherited Permissions

Summary

SpiceDB is an open source database system for creating and managing security-critical application permissions. Prior to version 1.47.1, if a schema includes the following characteristics: permission defined in terms of a union (+) and that union references the same relation on both sides (but one side arrows to a different permission). Then SpiceDB may have missing LookupResources results when checking the permission. This only affects LookupResources; other APIs calculate permissionship correctly.