The conversation view used on phones built its own sanitizer hook that
only caught `<img src>` starting with a lowercase scheme and inline
style `url()`, and its iframe CSP always allowed http(s) images. With
remote content blocked (the default `ask` policy) uppercase schemes,
srcset, `<source>`, video posters and background attributes still
loaded, so trackers fired when a phone user opened a thread.
The view now uses the desktop viewer's `blockExternalResourcesOnNode`,
and the strict iframe CSP is shared as `emailIframeCsp()` and applied
whenever remote content is blocked, together with `no-referrer`.
A newsletter's List-Unsubscribe `mailto:` was sent from the user's own
account as written: every `to=` field became a recipient, and subject
and body were the sender's choice. The confirmation said only
"Unsubscribe from this sender?", so one click could mail
"I resign" to someone's boss and HR.
The unsubscribe now goes to the single address in the URL (a list of
addresses is refused and `to=` is ignored), the subject is kept on one
line and both subject and body are capped. Both confirmations show the
recipient, subject and body before anything is sent.
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()`
Attachment thumbnails were object URLs typed with the sender's MIME
type. Object URLs share the webmail origin, so an `image/svg+xml`
attachment opened from its thumbnail ("Open image in new tab", or
dragged to the tab strip) ran the sender's script as the webmail in
Chromium and Firefox. The drag-out URL and Files thumbnails had the
same shape.
`fetchBlobAsObjectUrl` now re-types every blob to an inert type, and
image thumbnails in mail and Files go through `imageBlobUrl`, which
hands an SVG over as a `data:` URL: it still renders in the `<img>`,
but opened on its own it gets an opaque origin.
Only the host API methods checked a plugin's permissions. Every hook
and slot the sandbox reported was wired as-is, so a plugin declaring no
permissions could rewrite recipients and body of every outgoing mail
through `onTransformOutgoingEmail`, replace displayed bodies through
`onRenderEmailBody`, or read all fetched mail through
`onEmailsFetched`. Admin-installed plugins are managed, so users never
saw a consent prompt for any of it.
Each hook and slot now maps to a permission in
`lib/plugin-sandbox/permissions.ts`, checked the same way as API calls
(declared, and managed or granted). Hooks that change what is sent need
`email:send`, display takeovers need `email:render-takeover`, and a hook
or slot missing from the table is refused. Logout and account switches
stay implicit so plugins can always drop per-account state.
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.
A MAPI property in a TNEF attachment declares how many values follow.
The parser looped that many times even when a value could not be read
and nothing was consumed, so a 31-byte winmail.dat claiming 0xFFFFFFFF
values froze the tab for about 13 seconds on every open, longer with
more such properties. The count is now clamped to what the block can
hold and the loop stops as soon as a value consumes no bytes.
The Authentication-Results parser matched `dmarc=` and `dkim=` anywhere
in all headers joined together. A sender who used `dmarc=pass@...` as
the envelope address got a green DMARC pass for a message that failed,
because the server echoes that address in the SPF clause before its
real `dmarc=fail`. A sender could also add their own
Authentication-Results header to an unsigned message and get a DKIM and
DMARC pass. Calendar invites from such a message were shown as trusted.
The parser now splits each header on `;` outside quoted strings and
comments and reads the method only at the start of a part. DKIM, DMARC
and iprev come from the topmost header, which the receiving server
wrote; lower headers can only escalate SPF to a failure.
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.
The URL guard behind fetch-ical, OAuth discovery, branding and the
server-side JMAP fetches blocked only the single address 127.0.0.1 plus
the RFC 1918, link-local and ULA subnets. Any logged-in user could make
the server fetch 127.0.0.2, 100.64.0.0/10, 198.18.0.0/15, multicast,
reserved space or a NAT64/6to4/Teredo address that wraps an internal
IPv4 address.
The telemetry guard already rejected all of these (GHSA-m7j8), so its
range check moves to `lib/security/ip-ranges.ts` and both guards use it.
`guardedLookup` inherits the wider list, so the connect-time rebinding
check covers the new ranges too.
fetchUnifiedEmails and fetchCrossView set isUnifiedView:true synchronously
then await a network fetch with no check on completion that the view is
still current. If one resolved after the user had since selected a real
folder, it re-set isUnifiedView back to true while selectedMailbox stayed
on the folder - so a push-driven refreshCurrentMailbox (e.g. after
deleting a message) took the unified branch and blended in Inbox-tagged
messages instead of refreshing the folder.
Add a viewToken bumped by selectMailbox/selectKeyword/exitUnifiedView;
fetchUnifiedEmails/fetchCrossView capture it before fetching and discard
their result if it no longer matches on return. Also make selectMailbox/
selectKeyword defensively reset isUnifiedView/unifiedRole/crossView.
Upstream: bulwarkmail/webmail#1102
Linus Rath
Linus Rath
Luis Felipe Marzagao
Aaron Guise