Gramps Web API: Private Sub-Object Data in Non-Private Objects Exposed to Guest Users

Summary

Users with the Guest role could receive private sub-object data (e.g. private alternate names, private addresses, private note/citation/media handles) through list API endpoints such as GET /api/people/, GET /api/places/, GET /api/events/, and all other object list endpoints.

This does not expose objects (people, places, events, …) that are themselves marked private. Top-level private objects are correctly excluded from all responses. Only sub-object data attached to otherwise-public objects is affected.

Affected Versions

All versions of Gramps Web API prior to the fix.

Root Cause

The vulnerability originates from the behaviour of PrivateProxyDb.iter_*() in Gramps core. The ProxyDbBase.__iter_object() helper, which backs all iter_*() methods in PrivateProxyDb, correctly filters out top-level private objects but returns the remaining objects unsanitized — i.e. without stripping private sub-object references. In contrast, PrivateProxyDb.get_*_from_handle() does call the appropriate sanitize_*() function.

Gramps Web API's ModifiedPrivateProxyDb (which wraps the raw database for non-admin users) inherited this behaviour without override.

The same issue affects Gramps desktop features that consume iter_*() output: reports and exports generated via Gramps desktop using PrivateProxyDb may also include private sub-object data that should have been stripped.

Conditions Required

This issue only affects trees in which sub-objects have been explicitly marked private in Gramps desktop. The Gramps Web frontend UI does not expose controls for setting the private flag on sub-objects (alternate names, addresses, notes, citations, media references, event references, etc.). In practice, such flags are set in Gramps desktop and then synced or imported into Gramps Web.

Impact

When the conditions above are met, a user with the Guest role querying any list endpoint receives:

• Full content of private embedded sub-objects on people, such as alternate names (first name, surname, etc.) and addresses (street, city, etc.).
• Handles referencing private notes, citations, and media attached to places, events, sources, and other objects. These reveal the existence of private linked objects but not their content; fetching those objects by handle is correctly blocked by the proxy.

Fix

ModifiedPrivateProxyDb now overrides all iter_*() object methods to check obj.get_privacy() directly on the already-loaded object (eliminating the redundant per-object refetch) and to call the appropriate sanitize_*() function before yielding each object. This is consistent with the behaviour of get_*_from_handle() in PrivateProxyDb.