Addresses the primary finding from the May 27 security report (issue #8):
the admin widget preview modal (frontend/js/views/widgets.js) and the web
player widget renderer (server/player/index.html, 2 sites) loaded
user-authored widget HTML into unsandboxed iframes. Same-origin scripts
in the widget content could access window.parent.localStorage and
exfiltrate the JWT.
sandbox="allow-scripts" without allow-same-origin sandboxes the widget
into a unique origin: inline scripts (clock, RSS, weather widgets)
continue to work, but parent-origin access and same-origin requests are
blocked. Verified via Playwright probe against all 6 widget types in the
dev DB (clock, rss, social, text, weather, webpage): each renders
correctly under the new sandbox and contentDocument access from the
parent is blocked (opaque-origin enforcement working). Admin preview
unchanged in appearance; player display unchanged.
Webpage widget (server/routes/widgets.js) sandbox tightening (drop
allow-same-origin) is a separate forthcoming commit - needs test against
real embed URLs since some sites rely on same-origin behavior. The
sandbox-attribute intersection rule means today's outer-iframe sandbox
will cascade and strip allow-same-origin from the webpage widget's inner
iframe too; accepted as a narrow cosmetic regression (cookies/localStorage
stripped for embedded sites) until the deliberate inner-iframe handling
ships.
SECURITY.md added with reporting process (GitHub Security Advisories
primary, support@bytetinker.net fallback) and scope.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
