The preview hands the attachment's blob to the browser's own viewer,
which picks the viewer from the blob's type and downloads anything it
cannot show - under the blob's UUID. It only corrected the exact
application/octet-stream declaration from the file name. Other
declarations kept the preview from working: IBM i (AS/400) systems send
every attachment as application/x-as400attachment, some senders use
application/x-pdf or force-download, and the octet-stream check was
case-sensitive.
Move the decision into previewBlobType(): a PDF, image, audio or video
preview takes the first type its viewer can show - declared, then
served, then the one the file name implies. Other previews keep the
declared type unless it is generic, and the name never yields a
script-capable type.
The app refuses a JMAP server over plain http (loopback aside), yet the
desktop issued a code, reported "Signed in on your phone" once it was
redeemed, and the phone failed. Linking now stops before the step-up
with an explanation.
- An app password minted for a phone that never redeemed its code stayed
valid (no expiry, full permissions, no TOTP) and used up one of the
account's five app-password slots. It is now deleted, with its own
credential, when its grant is discarded or expires.
- Replaced codes were kept for twelve minutes each, so a session could
grow the store, and the cost of every request, without bound; only the
last three of a grant are kept now.
- A session read that failed after the credential check was taken for a
non-Stalwart server and handed the phone the account password; it now
refuses the pairing instead.
The token proxy trusted the endpoint sealed into a phone's refresh token
for good: after a server was removed or its provider moved, it kept
posting there with the plain fetch and whichever secret the server id
now maps to. Trust is now re-derived on every renewal; an endpoint the
webmail is no longer configured for gets neither the secret nor the
unguarded fetch.
The step-up for SSO accounts asks the provider for a new login with
`prompt=login`, but a provider that ignores it answers from its existing
session, so anyone at an unlocked desktop could link a phone. When the
ID token's `auth_time` is older than the step-up, the re-auth is now
refused.
The step-up's failure count was keyed on the cookie slot, which the
client chooses, so a session could spread guesses over 50 slots; and
even one key allowed 480 failures a day, well above Stalwart's ban of
100 a day per address, which would ban the webmail's own IP for every
user. Failures now count per server and login name, 5 per 15 minutes
and 20 a day.
The mobile handoff returned the provider's token endpoint and the
webmail's client id as they were. With a confidential client the phone
could not renew (it has no secret), and a provider on another host was
refused by the app outright. The handoff now returns the same bundle a
paired phone gets: such grants renew through `/api/auth/pair/token` with
a sealed refresh token.
"Link Mobile App" only appeared for OAuth sessions, its step-up could
only go through the identity provider (which failed without an OAuth
client and bounced password+TOTP users to the provider's login page),
and it handed the phone the desktop's own refresh token. Revoking that
token on sign-out, or a rotating provider, signed the phone out too; a
confidential client stopped the phone at its first token expiry; and an
identity provider on another host was refused by the app.
The step-up now mints the phone's own grant:
- Password and password+TOTP accounts confirm the current password (and
code) in the dialog. The server uses it once to get an OAuth grant
from Stalwart's structured login for the app's own client, retries
with the webmail's client when the server insists on a registered one,
and falls back to an app password ("Bulwark mobile (paired <date>)")
or, on servers that offer neither, the verified password. Failed
attempts are limited per account so the webmail's address cannot be
banned by guessing through it.
- SSO accounts keep the provider round trip, now with `offline_access`
where offered; its fresh tokens become the phone's grant instead of
being thrown away, and must belong to the account being paired.
- The account and server always come from the slot's verified session
context, never from the request.
Grants live 5 minutes server-side, codes 2 minutes, both single use; the
store is pinned on `globalThis`. Redeem answers `invalid_code`,
`expired_code` or `used_code`, and the desktop polls a separate status
id to replace the QR with "Signed in on your phone". A phone whose
client is confidential, or whose provider is on another host, renews
through `/api/auth/pair/token` with a sealed refresh token, so current
app builds work unchanged. Signing out discards a pending grant but no
longer affects a paired phone.
The dialog shows for every account (not in Lite), with a copyable
sign-in link, a TOTP field when needed, and the app's own "Scan a
sign-in code" wording.
The step-up for linking a device sends the user to the identity
provider with `prompt=login`. The login route accepted that pending
state too, so a code from the re-auth could be spent there and sign this
browser in as whichever account answered the prompt. It now refuses a
re-auth state; only the pairing route completes one.
The callback page also handles its code once. React's development
double effect ran it twice: the second pass no longer saw the re-auth
flag and raced the pairing route for the single-use code.
With custom JMAP endpoints allowed, the password+TOTP login posted the
admin's client secret to `/auth/token` on whatever server the user
named. The secret now only goes to admin-configured servers.
The Stalwart bundle's README told admins to use
`releases/latest/download/bulwark-lite-stalwart.zip` as `resourceUrl`.
Stalwart re-downloads that URL on its own schedule and checks no hash or
signature, so whatever the newest release held would run as script on
the Stalwart origin next to the web admin.
The README now installs from the tagged release, explains updating by
moving `resourceUrl` to the next tag, and describes the floating URL as
an opt-in with that risk spelled out. Release runs upload a `.sha256`
next to each Lite zip.
The static export's header policy has to allow inline scripts (the
hydration scripts differ per page and one header cannot list them all),
so any injected inline script ran. The Stalwart bundle had no policy at
all: Stalwart sends no security headers for an Application, and nothing
stopped another site from framing it.
- Postbuild gives every page of the static target a `<meta>` CSP that
allows exactly the page's own inline scripts; enforced together with
the host's header, it takes away `'unsafe-inline'`. `verify` fails a
page whose inline scripts are not all pinned.
- The Stalwart entry document carries a `<meta>` CSP (no plugins, eval,
foreign scripts or moved `<base>`; its shells are rewritten at runtime,
so hashes are not possible there) and refuses to run inside a frame
of another origin.
- The nginx and Caddy examples send the same CSP as `_headers`.
The mock JMAP server behind `/api/dev-jmap` accepts any password and
shipped in every image, held back only by `DEV_MOCK_JMAP=true` at
runtime. It now also needs the flag at build time (inlined through
`next.config.ts`), so a build made without it cannot switch the mock on,
and the Docker image drops the route before building.
Several endpoints answered anyone with what fingerprints a deployment:
`/api/health?detailed=true` (versions, memory), the update status
(exact version and the text of a pending security advisory, even with
`loginShowVersion` off), `/api/plugins` (installed plugins and the hosts
they may reach), the admin policy (push relays, sidebar app URLs,
plugin lists) and `/api/config` (every domain each server serves).
Visitors without a session now get:
- the plain liveness answer from `/api/health`;
- the update status only where the login page shows the version, and
never the advisory text;
- a 401 from `/api/plugins`, which the client only syncs after signing
in;
- the policy without plugin lists, push relays and sidebar apps, marked
`X-Bulwark-Policy-Scope: public`; the client fetches the full policy
once it signs in;
- server domain lists only when servers are picked by domain.
A mailbox session, a remembered session cookie or the admin session
counts as signed in. Deployments without a session secret cannot tell
sessions apart and keep the old answers.
A full sign-out emptied the stores but left the accounts' traces in the
browser for the next person at the computer: search history, open tabs
with message subjects, Files favourites and recent files, calendar
alert acknowledgements, and attachment bytes a plugin had staged for an
upload that never started. Other open tabs kept showing the signed-out
accounts' mail, and the boot snapshot of the mailbox list was restored
for whichever account happened to be active next.
- A full sign-out now removes those keys and the staged files, and
tells the other tabs through a `storage` event so they leave for the
login page.
- The boot snapshot names its account and is only restored for it.
- The login form only remembers the username for suggestions when the
user did not decline "remember me".
Device preferences and `template-storage` stay: with settings sync off
they exist only on this browser.
`api.storage` kept one `plugin:<id>:` namespace for everyone signed in
to the browser and left it behind after signing out, so a plugin read
what it had stored for the previous account, such as quick-notes'
notes on someone else's mail.
Keys now carry the account (`plugin:<id>:@<account>:<key>`). Signing an
account out or removing it deletes its keys, and a full sign-out
deletes all plugin storage. Keys written before this change are handed
to the first account that uses the plugin. Uninstalling a plugin still
removes everything under its prefix.
A WOPI token carries the user's credentials to the editor server and
stayed valid for its whole six-hour lifetime, so an editor opened
before signing out could still read and save the document afterwards.
Each token now records the browser (a random id in an HttpOnly cookie,
hashed) and account slot that opened it. Signing out records a
revocation time for that browser and slot, or for every slot on a full
sign-out, and WOPI calls with a token minted before it are refused.
Signing out on another device leaves this browser's editors alone.
Revocations live in the state directory, so they survive a restart and
reach replicas sharing the state volume, and are dropped once the
tokens they cover have expired.
`/api/auth/verify` checked any username and password against the JMAP
server without a limit. Every probe reaches the server from the
webmail's own address, so the route was a password oracle and enough
wrong passwords could trip Stalwart's authentication ban against the
webmail itself, locking out every user.
Wrong passwords now use up a budget of five per client and thirty
across all clients per fifteen minutes; right ones are refunded. Over
budget the route answers `inconclusive` and the browser probes the JMAP
server itself, as it did before the pre-check existed.
Used impersonation token ids were only remembered in process memory, so
a captured handoff link could be redeemed a second time within its five
minute lifetime once the process restarted, or on another replica. Each
used id now also leaves a marker file in the state directory, created
exclusively, which every replica sharing the state volume sees; markers
are pruned once the token could no longer verify.
The absolute session limit comes from the eight-hour app password that
Stalwart itself expires.
The startup banner printed `/setup?token=...`, so the one-hour bootstrap
token that grants the setup wizard landed in reverse-proxy access logs,
Referer headers and browser history. The link now carries the token in
the fragment, which never leaves the browser, and the wizard removes it
from the address bar as soon as it reads it. Old `?token=` links still
work and are cleaned up the same way.
The inline sidebar apps hand their origins to the proxy through a
client-written cookie, which the proxy merges into `frame-src`. Any
same-site sibling host could set that cookie too. Over HTTPS the cookie
is now `__Host-bulwark_app_frame_origins`, which only this exact host
can set, and the proxy ignores the unprefixed name there. Plain HTTP
(local development) keeps the old name.
`/api/favicon` is unauthenticated and answers on the webmail origin,
and it passed the upstream Content-Type through unchecked. Should the
favicon service ever return `image/svg+xml` or `text/html`, opening
that URL on its own would run script as the webmail. Only raster image
types are served now, with `nosniff` and a sandboxing CSP; anything
else falls back to the transparent placeholder.
Paths the proxy skips (static files, `/_next`, `/api`) got no security
headers at all, so the not-found shell rendered for a missing
`/foo.html`, `/branding/x` or an unknown `/api` route could be framed
by any site. Skipped responses now carry `nosniff` and
`X-Frame-Options: DENY`, and non-API ones `frame-ancestors 'none'`;
API routes keep setting their own CSP.
Bulwark Lite deleted the remembered refresh token on any non-5xx error
from `/auth/token`, so a 429 or 408 during a busy moment signed the
user out for good. Like the server build, it now clears the token only
when the server refuses it (400, 401, 403) and treats everything else
as an outage.
Linus Rath
Linus Rath
dealerweb
lucamzanon