Several API endpoints checked only the coarse Events/Monitors permission
and not the per-monitor object ACL, so a user explicitly denied a monitor
could still reach that monitor's objects by addressing them directly:
- EventsController::edit() and ::delete() checked Events=Edit but never
called canEdit() on the event, so any event could be mutated or deleted
by Id.
- FramesController only guaranteed Events != None in beforeFilter().
view() returned any frame by Id, and edit()/delete() mutated frames
without requiring Events=Edit or checking the parent event at all.
- ZonesController::forMonitor() listed zones for any monitor Id.
Resolve the owning object and apply the same canView()/canEdit() checks
the normal read paths already use. Frames are addressed by their own Id,
so their parent event is looked up to reach the monitor ACL.
Refs GHSA-hw39-qpjw-p7cg.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
