Parse Server 9.0.0 before 9.10.1 Protected Fields Disclosure via LiveQuery

Summary

Parse Server is an open-source backend server. In versions >= 9.0.0 and < 9.10.1-alpha.8, and in versions < 8.6.89, LiveQuery evaluates the protectedFields class-level permission against an incompletely resolved caller identity: the subscriber's roles are not resolved, and when a subscription does not supply its own session token the event payload is redacted against an anonymous identity even though the read was authorized against the connected user. As a result, field masks defined for a role, for authenticated users, or for a specific user are not applied, so an authenticated subscriber can receive field values that the REST API correctly withholds and can use a masked field to filter or watch a subscription. Only classes with LiveQuery enabled that define protectedFields under a role:, authenticated, or per-user group are affected; masks under the public (*) group are applied correctly. The issue is fixed in 9.10.1-alpha.8 and 8.6.89. As a workaround, additionally define the affected field masks under the public (*) group, or disable LiveQuery for classes whose class-level permissions rely on role-scoped, authenticated, or per-user protectedFields groups.