diff --git a/changelog.d/3641.bugfix b/changelog.d/3641.bugfix new file mode 100644 index 0000000000..02181975c0 --- /dev/null +++ b/changelog.d/3641.bugfix @@ -0,0 +1 @@ +Fix a potential event disclosure issue \ No newline at end of file diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py index 48f26db67c..10e71c78ce 100644 --- a/synapse/federation/federation_server.py +++ b/synapse/federation/federation_server.py @@ -425,6 +425,7 @@ class FederationServer(FederationBase): ret = yield self.handler.on_query_auth( origin, event_id, + room_id, signed_auth, content.get("rejects", []), content.get("missing", []), diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py index 20fb46fc89..60391d07c4 100644 --- a/synapse/handlers/federation.py +++ b/synapse/handlers/federation.py @@ -1349,6 +1349,11 @@ class FederationHandler(BaseHandler): def get_state_for_pdu(self, room_id, event_id): """Returns the state at the event. i.e. not including said event. """ + + event = yield self.store.get_event( + event_id, allow_none=False, check_room_id=room_id, + ) + state_groups = yield self.store.get_state_groups( room_id, [event_id] ) @@ -1359,8 +1364,7 @@ class FederationHandler(BaseHandler): (e.type, e.state_key): e for e in state } - event = yield self.store.get_event(event_id) - if event and event.is_state(): + if event.is_state(): # Get previous state if "replaces_state" in event.unsigned: prev_id = event.unsigned["replaces_state"] @@ -1391,6 +1395,10 @@ class FederationHandler(BaseHandler): def get_state_ids_for_pdu(self, room_id, event_id): """Returns the state at the event. i.e. not including said event. """ + event = yield self.store.get_event( + event_id, allow_none=False, check_room_id=room_id, + ) + state_groups = yield self.store.get_state_groups_ids( room_id, [event_id] ) @@ -1399,8 +1407,7 @@ class FederationHandler(BaseHandler): _, state = state_groups.items().pop() results = state - event = yield self.store.get_event(event_id) - if event and event.is_state(): + if event.is_state(): # Get previous state if "replaces_state" in event.unsigned: prev_id = event.unsigned["replaces_state"] @@ -1706,8 +1713,19 @@ class FederationHandler(BaseHandler): defer.returnValue(context) @defer.inlineCallbacks - def on_query_auth(self, origin, event_id, remote_auth_chain, rejects, + def on_query_auth(self, origin, event_id, room_id, remote_auth_chain, rejects, missing): + in_room = yield self.auth.check_host_in_room( + room_id, + origin + ) + if not in_room: + raise AuthError(403, "Host not in room.") + + event = yield self.store.get_event( + event_id, allow_none=False, check_room_id=room_id + ) + # Just go through and process each event in `remote_auth_chain`. We # don't want to fall into the trap of `missing` being wrong. for e in remote_auth_chain: @@ -1717,7 +1735,6 @@ class FederationHandler(BaseHandler): pass # Now get the current auth_chain for the event. - event = yield self.store.get_event(event_id) local_auth_chain = yield self.store.get_auth_chain( [auth_id for auth_id, _ in event.auth_events], include_given=True diff --git a/synapse/storage/event_federation.py b/synapse/storage/event_federation.py index 8d366d1b91..7cd77c1c29 100644 --- a/synapse/storage/event_federation.py +++ b/synapse/storage/event_federation.py @@ -343,6 +343,7 @@ class EventFederationWorkerStore(EventsWorkerStore, SignatureWorkerStore, table="events", keyvalues={ "event_id": event_id, + "room_id": room_id, }, retcol="depth", allow_none=True, diff --git a/synapse/storage/events_worker.py b/synapse/storage/events_worker.py index 67433606c6..6b8a8e908f 100644 --- a/synapse/storage/events_worker.py +++ b/synapse/storage/events_worker.py @@ -19,7 +19,7 @@ from canonicaljson import json from twisted.internet import defer -from synapse.api.errors import SynapseError +from synapse.api.errors import NotFoundError # these are only included to make the type annotations work from synapse.events import EventBase # noqa: F401 from synapse.events import FrozenEvent @@ -76,7 +76,7 @@ class EventsWorkerStore(SQLBaseStore): @defer.inlineCallbacks def get_event(self, event_id, check_redacted=True, get_prev_content=False, allow_rejected=False, - allow_none=False): + allow_none=False, check_room_id=None): """Get an event from the database by event_id. Args: @@ -87,7 +87,9 @@ class EventsWorkerStore(SQLBaseStore): include the previous states content in the unsigned field. allow_rejected (bool): If True return rejected events. allow_none (bool): If True, return None if no event found, if - False throw an exception. + False throw a NotFoundError + check_room_id (str|None): if not None, check the room of the found event. + If there is a mismatch, behave as per allow_none. Returns: Deferred : A FrozenEvent. @@ -99,10 +101,16 @@ class EventsWorkerStore(SQLBaseStore): allow_rejected=allow_rejected, ) - if not events and not allow_none: - raise SynapseError(404, "Could not find event %s" % (event_id,)) + event = events[0] if events else None - defer.returnValue(events[0] if events else None) + if event is not None and check_room_id is not None: + if event.room_id != check_room_id: + event = None + + if event is None and not allow_none: + raise NotFoundError("Could not find event %s" % (event_id,)) + + defer.returnValue(event) @defer.inlineCallbacks def get_events(self, event_ids, check_redacted=True,