Critical: Leaflet marker popups built untrusted Nostr event fields (and
BTC Map API fields) into innerHTML, bypassing React's output encoding. Any
user could publish a spot/tour/crew/event with an <img onerror> payload in a
text field; it executed on /map render with no interaction, letting injected
script read the plaintext nsec from localStorage (nostr:login) and the Cashu
seed (cashu-mnemonic) — permanent, unrotatable account + wallet takeover.
Fixes in src/components/SpotMap.tsx:
- Rebuild all popup DOM with createElement + textContent instead of innerHTML
for every untrusted field: spot.location; tour.title/location/meetingPoint;
evt.title/location; crew.name/location; BTC Map name/address/opening_hours/
phone/description.
- Validate every event/API URL with sanitizeUrl() before it reaches an
href/src: crew.image (popup + marker icon) and BTC Map website. Drop
anything that isn't http(s). tel: links reduced to safe characters.
- Replace inline onerror handler on the crew marker image (would be blocked
by CSP anyway) with a scripted img.onerror fallback.
- Add popupRow() helper so untrusted detail rows can never be innerHTML'd.
Defense in depth (web only, native Capacitor build unaffected):
- Add public/_headers with a strict Content-Security-Policy: default-src
'none'; script-src 'self' 'wasm-unsafe-eval' (no unsafe-inline/eval);
object-src 'none'; base-uri 'none'; frame-ancestors 'none'; plus the
https:/wss: allowances a Nostr client genuinely needs for relays, media,
and mints. Also X-Content-Type-Options, X-Frame-Options, Referrer-Policy,
Permissions-Policy.
- Move the inline boot-crash-guard script to public/boot-guard.js so
script-src can stay 'self' with no 'unsafe-inline'; index.html now loads it
externally. The guard also now paints errors via textContent, not innerHTML.
Co-authored-by: shakespeare.diy <assistant@shakespeare.diy>
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