CVE-2024-54151: Directus allows unauthenticated access to WebSocket events and operations

Summary When setting WEBSOCKETSGRAPHQLAUTH or WEBSOCKETSRESTAUTH to "public", an unauthenticated user is able to do any of the supported operations (CRUD, subscriptions) with full admin privileges.

Details Accountability for unauthenticated WebSocket requests is set to null, which used to be "public permissions" until the Permissions Policy update which now defaults that to system/admin level access. So instead of null we need to make use of createDefaultAccountability() to ensure public permissions are used for unauthenticated users.

PoC 1. Start directus with bash WEBSOCKETSENABLED=true WEBSOCKETSGRAPHQLAUTH=public WEBSOCKETSRESTAUTH=public

2. Subscribe using GQL or REST or do any CRUD operation on a user created collection (system tables are not reachable with crud) gql subscription { directususersmutated { key event data { id email firstname lastname password } } } or json { "type": "items", "action": "read", "collection": "yourcollectionname" } 3a. Open up the data studio as any user. Observe how the subscriber gets notified on each page navigation (because the users lastpage gets updated, the password fields is properly redacted here)

3b. Observe receiving all available items from the yourcollectionname collection.

Impact

This impacts any Directus instance that has either WEBSOCKETSGRAPHQLAUTH or WEBSOCKETSRESTAUTH set to public allowing unauthenticated users to subscribe for changes on any collection or do REST CRUD operations on user defined collections ignoring permissions.