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 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.
`/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.
Clicking a new-mail notification opened `/mail/message/<id>` in
whichever account was active. With several accounts signed in, that
looked the id up in the wrong account: nothing opened, or a different
message did and was marked read.
The preview API now returns the cookie slot of the login that owns the
notified account, the service worker adds it to the permalink (or links
that account's Inbox for a group notification), and the app switches to
the login on that slot before opening the message.
The code exchange, token refresh and revocation POSTs carry the
authorization code, refresh token and client secret, and used a plain
`fetch` that follows redirects. The endpoints come from a validated
discovery document, but a redirect from them (or from an endpoint that
changed after discovery) re-sent the body to a host nobody validated.
These requests now fail on any redirect. A failed refresh still keeps
the refresh token, as for any other outage.
A failed TOTP login returned the first 500 bytes of the upstream error
body. With custom JMAP endpoints allowed and no server configured, the
upstream is any address the caller names, so the route read other
servers' responses on the caller's behalf. The detail is now only
passed on from an admin-configured server.
A Bearer login may claim a bare local part, which is accepted when the
server's `Session.username` has the same local part (TOTP users who
type `john` log in this way). Settings were keyed on that claim, so on a
multi-domain server `john@b.example` could claim `john` and read and
overwrite the synced settings of the `john@a.example` who signs in as
`john` with a password.
`resolveJmapIdentity` now returns the canonical account name for a bare
Bearer claim, the context cookie carries it as `accountName`, and the
settings route keys on it. Basic logins and fully-qualified claims keep
their existing key.
The theme sanitizer was a short denylist. It missed protocol-relative
`url(//host)`, schemes and keywords spelled with CSS escapes
(`url(\68ttps:...)`, `@\69mport`), `image-set("https://...")` and
`@font-face` sources, so a theme could load remote resources from the
app document. `validateThemeSelectors` was never called, so theme CSS
could also target `input[type=password]` or restyle real UI. The admin
routes and the zip validator only sanitized when the safety check
failed, and CSS returned by the `onThemeBeforeApply` plugin hook was
injected as-is.
- every `url()` except a `#fragment` and every `image-set()` is removed
with its arguments; a banned construct spelled with escapes drops the
whole stylesheet
- theme CSS keeps only `:root` and `.dark` rules (no nested rules),
plus `@font-face`, `@keyframes` and `@media`/`@supports` wrappers
- sanitizing is unconditional everywhere, including plugin-transformed
CSS; compiled token values may not contain escapes or `url()`
The Stalwart admin check only bailed while `allowCustomJmapEndpoint` was
on. A context cookie minted while it was on keeps naming the
user-chosen server, and the envelope has no expiry, so after the admin
turned the switch off that server could still answer the admin probe
and mint a Bulwark admin session. The check now also requires the
cookie's server to be an admin-configured one.
The Stalwart admin check probed `x:Account/query`. Stalwart's default
tenant-admin role carries `sysAccount*`, so an administrator of a single
tenant passed and, in the default `auto` mode, was signed into the
Bulwark dashboard, which configures the whole instance for every
tenant. The `auto|password|off` switch added for #870 left the default
at `auto`, so the advisory never held on a default install.
The probe is now `x:Tenant/query`, which needs `sysTenantQuery`: by
default only the server-wide superuser holds it.
GetFile answered on the webmail origin with the Content-Type stored in
the WOPI token, which for a mail attachment comes straight from the
launch request and for a Files node is a user-settable property. No
CSP, nosniff or disposition was added, since `/api/*` skips the proxy.
A user could mint a token for their own blob typed `text/html` and have
a victim open the GetFile URL, running script in the webmail origin.
GetFile now always sends `application/octet-stream` with
`Content-Disposition: attachment`, `nosniff` and a sandboxing CSP, and
refuses browser loads (any `Sec-Fetch-Dest` other than `empty`). The
editor fetches it server-to-server, so it is unaffected.
The origin gate in the proxy only covered `/api/auth/*`. The JMAP
passthrough, `/api/settings`, `/api/wopi/launch`,
`/api/plugin-approval-status`, `/api/fetch-ical`, `/api/translate`,
`/api/caldav/discover`, `/api/calendar-agenda` and `/api/webdav` all act
with the session cookie and had no origin check. A page on a same-site
sibling origin receives SameSite=Lax cookies, so it could run arbitrary
JMAP as the signed-in user, including sharing mailboxes to a third
account.
The proxy now gates every `/api/` route except the WOPI file endpoints
the office editor calls server-to-server, and each of these handlers
checks again. The proxy also decides on the decoded path, so an escaped
spelling such as `/api/%61uth/session` no longer skips the gate.
An impersonation handoff sealed `<target>%<master>` and the master
password into the session cookie, and `PUT /api/auth/session` hands that
cookie's contents to the browser on every restore. Anyone who received
a handoff could read a credential that signs in as every mailbox and
into Stalwart administration, with no expiry and no audit trail.
The impersonate route now uses the master credential server-side, once,
to create an app password on the target mailbox that expires after
8 hours. Only that app password reaches the cookies. Signing out
revokes it through a sealed grant cookie, and PUT refuses any session
that still holds the configured master password, so cookies minted
before this change are dropped instead of returned.
A PatchObject key is a JSON Pointer (RFC 8620 section 5.3), so a slash
inside the member name it points at has to be escaped as `~1`. Keyword
patches were built as `keywords/${keyword}` verbatim, which is fine for
every flat keyword but wrong for a nested tag: `$label:work/clients`
became the pointer `keywords/$label:work/clients`, asking for the
`clients` member of the `$label:work` keyword rather than for the keyword
itself. The patch is not a boolean at that path, so the server rejects or
ignores it and the tag never lands.
Route the keyword patch sites - setKeyword, removeKeyword, migrateKeyword
and the category-tab batch patch - through `keywordPointer`, which escapes
per RFC 6901 the way the calendar store already does for participant ids.
Flat keywords are untouched, so `$seen`/`$flagged` and friends keep the
exact pointers they had. The dev JMAP mock reads the escaping back, or
nested tags would behave differently against the mock than against a real
server.
migrateKeyword also took any answer as success: a method-level error on
the query read as "no message carries this keyword", one on the write was
ignored outright, and a per-message refusal was invisible - so a rename
that moved nothing still reported a clean migration. It now answers with
{ migrated, refused }, because the work is batched and a failure partway
through cannot undo the batches already applied. A whole batch the server
refuses stops the rest, which it would refuse too; a single message it
refuses does not, the mail behind it being unaffected. A query error
throws, nothing having been written yet, and so does a run that migrated
nothing at all - the case where the caller must not rename a tag over
messages that all kept the old keyword.
The walk over tagged mail was not paginating safely either. It stopped at
the first page shorter than the limit it asked for, but RFC 8620 section
5.5 lets a server clamp that limit, so a clamping server left most of the
mail unmigrated. Positions are also only comparable within one queryState,
which the walk ignored: mail arriving mid-walk shifts every later page. It
now restarts when the state changes under it, and gives up - before any
write, so the caller can simply repeat - once a mailbox has moved under it
three times, rather than mixing ids from states that no longer agree. A
page carrying no id it has not already seen ends the walk, which keeps it
bounded against a server that answers every position with the same page.
Linus Rath
Linus Rath
Paulhenry Saux
KazNIISA IT