SharedObjectManager scopes querysets to what a user may see, which
includes other people's public and shared-with-them objects. Several
mutating rule endpoints treated that visibility as permission to write.
Generalise get_owned_object_or_403 into get_shared_object_or_error, which
takes an explicit access level instead of inferring one:
- READ requires the object to be visible; denial is 404 so the response
does not confirm that an id exists.
- EDIT requires ownership; denial is 403, but only after the visibility
check, so 403 never leaks the existence of an invisible object. This
matters for TransactionRuleAction, whose manager is unscoped.
The previous owner_path resolved to a User and discarded the object, so
it could not express visibility at all. via= now points at the governing
SharedObject and is resolved with a plain getattr, so an unresolvable
path raises instead of silently granting access.
is_visible_to/is_editable_by replace is_accessible_by, which was never
called and tested visibility == "shared", a value that does not exist in
Visibility.
Also fixes two further holes in the same module:
- transaction_rule_delete fell through to delete() whenever the caller
was not in shared_with, so any user could delete a public rule. Now
only the owner deletes; a shared user revokes their own access.
- transaction_rule_view was read-only but is now explicitly READ, so
rules shared with a user stay viewable.
The activate/deactivate control is hidden for rules the user does not
own, instead of rendering a button that always fails.
Refs GHSA-83g9-vjqf-2j5q
Herculino Trotta