- Including Authentication re-arms protect_from_forgery on DiskController.
Active Storage's direct-upload service PUT (#update) sends only signed
service headers and no CSRF token, so a real authenticated upload would
422 storing bytes. Re-exempt #update from forgery protection; the signed
URL token and session check still gate the write.
- Swap the raw skip_before_action for the Authentication concern's
intent-revealing allow_unauthenticated_access / allow_bot_access helpers
on #show, matching the rest of the app.
- Scope the test's ActiveStorage::Current.url_options override to a
set { } block so it can't leak thread-local state into later tests.
ActiveStorage's direct-upload endpoints ship unauthenticated by Rails
default: ActiveStorage::DirectUploadsController and DiskController inherit
from ActionController::Base, so they bypass the app's Authentication
concern. That leaves the write path open — anyone could mint blob records
and PUT bytes to local disk storage.
Campfire never uses direct upload for legitimate attachments. Those flow
through MessagesController#create (already authenticated), and Trix file
drops are disabled in the composer. Gating the write path is therefore
pure defense-in-depth with no functional cost.
Require an authenticated session on the two write actions
(DirectUploadsController#create and DiskController#update) by including the
existing Authentication concern. Blob serving stays public —
DiskController#show keeps its auth skip, and the Blobs/Representations
controllers are untouched — so message attachments and the account logo
keep loading. Because these controllers live in ActiveStorage::Engine and
only see the engine's url helpers, also include the application route
helpers so the concern can redirect to new_session_url on failure (302,
write blocked).
Jeremy Daer