An adversarial pass found 5 Critical XSS sinks where props declared number/enum
in TypeScript were interpolated raw into exported HTML attribute values,
trusting the type — but nothing enforces it at runtime (AI update_props only
validates node_id; deserialized saved state is untyped JSON). Fixed all 5
(NumberCounter data-target, StarRating aria-label, FormContainer method,
ContactForm/InputField input type) plus 6 sibling sinks found by an exhaustive
audit of every attribute-value interpolation across src/components: a
JS-source injection into ContentSlider's inline setInterval script, a
prototype-pollution-adjacent allowlist gap in Section's divider-shape lookup,
TextareaField rows, Testimonials rating aria-label, HeroSimple textAlign, and
MapEmbed zoom. Adds shared sanitizeFormMethod/sanitizeInputType allowlist
helpers to utils/escape.ts alongside the existing escapeAttr/safeUrl/cssValue
primitives. Every fix is TDD'd: a malicious-value test reproduces the raw
injection against the pre-fix code, then passes after the fix.
502 tests green (npx vitest run), tsc + vite build green (npm run build).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Adversarial re-review found the C1 fix incomplete plus an adjacent
same-class XSS, both reachable via the AI update_props path and
deserialized saved state:
- cssPropsToString only ran sanitizeCssValue on typeof-string values, so a
non-string style value (array/object) with a valid key skipped
sanitization entirely and was template-coerced raw into style="...",
e.g. { color: ['red', '"><img src=x onerror=alert(1)>'] }. Now every
non-number value is coerced with String() and sanitized; numbers stay
raw. sanitizeBreakoutChars also now escapes < and > (previously only ;
and ") as defense-in-depth, since values can reach it from non-string
sources.
- props.tag (Container) and props.level (Heading) were interpolated raw
into the tag position of exported HTML (`<${tag}`, `<${level}`) with no
runtime validation, letting a malicious value break out of the tag
entirely. Both are now allowlisted/clamped against their known-safe sets
(div/section/article/header/footer/main; h1-h6), falling back to
div/h2. Applied in Container's live render + toHtml, Heading's live
render + toHtml, and the typeName==='div' fallback branch in
html-export.ts's renderNode (hit for unresolved/legacy node types).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
shadowdaoandClaude Opus 4.8