SurrealDB: Field-level SELECT permissions bypassed via graph and reference traversals

A record user could read field values hidden from them by field-level SELECT permissions by reaching the records through a graph-edge (->) or back-reference (<~) traversal instead of a direct SELECT.

When a table was readable at the table level but carried a field hidden by a field-level permission (DEFINE FIELD secret ON knows PERMISSIONS FOR select NONE), a direct SELECT * FROM knows hid secret — but reaching the same records through a traversal that yields full objects — person:bob->(SELECT * FROM knows), person:bob<~(SELECT * FROM comment), or a projected target vertex ->knows->(SELECT * FROM person) — returned it intact.

The root cause: the shared resolve_record_batch helper used by GraphEdgeScan (FullEdge) and ReferenceScan (FullRecord) enforced only the table-level SELECT permission and pushed raw record data, never running the field-level filtering (build_field_state / filter_fields_by_permission) that ordinary table scans and fetch_record apply.

Impact

A record user can read the values of fields hidden by field-level SELECT permissions, on tables they already hold table-level SELECT on, by materialising the records through a graph-edge, back-reference, or target-vertex traversal — recovering the values directly, for every record the traversal returns.

The disclosure is confined to the field-permission layer: it grants no unauthorised cross-table, cross-record, or cross-namespace/database access. The table's own SELECT permission — including any row-level WHERE predicate — is still enforced, so the caller only reaches records they were already entitled to read; only the per-field SELECT filtering within those records is skipped. Root and record-owner sessions are unaffected, and data cannot be modified (confidentiality only).

Table-level enforcement on these traversals landed in 3.1.0 (the fix for GHSA-vjjx-rfw4-rmfc); releases before 3.1.0 additionally exposed whole records on tables the caller could not read, and are covered by that advisory.

Patches