Five low-risk, high-value fixes surfaced by the security review:
#3 Branding lockdown — `custom_domain`/`custom_css` (which feed the PUBLIC,
pre-auth branding resolver and the login-page <style>) are now settable only
by platform admins; a workspace_admin can no longer hijack the platform login
page by claiming its domain. The public /api/branding (+ /domain) now return
only presentational fields via publicBranding() (no id/user_id/workspace_id/
custom_domain/timestamps leak).
#6 Strip device_token — the device WS auth secret (validated with
timingSafeEqual) was returned in device list/get/update + pairing responses
(SELECT d.* / *). New lib/device-sanitize.js strips it everywhere; prevents
device impersonation by any workspace user.
#7 must_change_password enforced server-side — was a frontend-only redirect, so
a provisioned temp password worked indefinitely via the API. requireAuth now
403s every route except GET/PUT /api/auth/me (the password change, which
clears the flag) and logout while the flag is set.
#8 XSS — escape user data interpolated into innerHTML in teams.js, kiosk.js,
layout-editor.js (team/page/layout/zone names, member name/email, kiosk
config fields). scriptSrcAttr 'unsafe-inline' made these exploitable via
injected event handlers, not just markup.
#9 Thumbnail IDOR — /api/content/:id/thumbnail had no auth/scope gate (any UUID
served any tenant's thumbnail). Now mirrors the /file route's playlist/widget
workspace-scoped reference check.
Tests: new test/security-fixes.test.js (device strip, publicBranding field
allowlist, must_change_password gate). Full suite 41/41. Verified live against a
prod-data copy: device_token absent from /api/devices, /api/branding trimmed.
Not addressed here (tracked for follow-up): Android OTA signature verification
(Critical), public widget-render XSS, token revocation/logout, pairing-code
strength, validateRemoteUrl hardening, import quota.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
ScreenTinker - open source digital signage management software.
MIT License, all features included, no license gates.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
