fix(builder): escape/allowlist all attribute-value sinks incl. numeric/enum props (XSS)

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>

craft/src/components/sections/ContentSlider.toHtml.test.ts

@@ -110,3 +110,23 @@ describe('ContentSlider.toHtml renders slide.imageSrc as a background-image (INT
     expect(html).toContain('background-color:#123456');
   });
 });
+
+describe('ContentSlider.toHtml interval is NOT runtime-type-checked -- must be coerced before it reaches the inline <script> numeric context', () => {
+  test('a malicious interval string cannot inject arbitrary JS into the autoplay setInterval call', () => {
+    const malicious = '5000);alert(document.domain);//';
+    const { html } = toHtml({ slides, autoplay: true, interval: malicious }, '');
+    expect(html).not.toContain('alert(document.domain)');
+    // the setInterval call must still be well-formed with a plain numeral delay
+    expect(html).toMatch(/setInterval\(function\(\)\{show\(current\+1\);\},\d+\);/);
+  });
+
+  test('a non-numeric interval falls back to a safe default delay', () => {
+    const { html } = toHtml({ slides, autoplay: true, interval: 'not-a-number' }, '');
+    expect(html).toMatch(/setInterval\(function\(\)\{show\(current\+1\);\},5000\);/);
+  });
+
+  test('a normal numeric interval still renders as the exact configured delay', () => {
+    const { html } = toHtml({ slides, autoplay: true, interval: 3000 }, '');
+    expect(html).toMatch(/setInterval\(function\(\)\{show\(current\+1\);\},3000\);/);
+  });
+});

craft/src/components/sections/ContentSlider.tsx

@@ -250,11 +250,24 @@ ContentSlider.craft = {
   } = props;
 
   const items = slides.length > 0 ? slides : defaultSlides;
+  // Number() coercion: `interval` is declared `number` in TS but is NOT
+  // type-checked at runtime -- it arrives raw via the AI `update_props`
+  // path or a deserialized saved-state blob and is interpolated directly
+  // into the inline <script>'s `setInterval(fn, ${interval})` call below as
+  // a bare JS numeral (no quotes around it). A string like
+  // `5000);alert(1);//` would previously close the setInterval() call and
+  // splice arbitrary JS into the page's own <script> tag -- worse than an
+  // HTML attribute breakout, since it runs unconditionally on page load.
+  // Number() of anything non-numeric collapses safely to NaN, so we fall
+  // back to the 5000ms default rather than ever interpolating a
+  // non-numeral.
+  const intervalNum = Number(interval);
+  const safeInterval = Number.isFinite(intervalNum) && intervalNum > 0 ? intervalNum : 5000;
   // Deterministic AND unique id, scoped on the Craft node id, for this
   // slider's slide/dot element ids and inline-script globals -- so two
   // ContentSlider instances (e.g. both left at default slides) don't
   // collide and end up driving each other's rotation.
-  const uid = scopeId(nodeId, JSON.stringify(items) + interval, 'cs');
+  const uid = scopeId(nodeId, JSON.stringify(items) + safeInterval, 'cs');
 
   const sectionStyle = cssPropsToString({
     position: 'relative',
@@ -339,7 +352,7 @@ ContentSlider.craft = {
     window["${uid}_prev"]=function(){ markManualNav(); show(current-1); };
     ${autoplayActive ? `
     var timer=null;
-    function start(){ if(!timer && document.visibilityState!=="hidden"){ timer=setInterval(function(){show(current+1);},${interval}); } }
+    function start(){ if(!timer && document.visibilityState!=="hidden"){ timer=setInterval(function(){show(current+1);},${safeInterval}); } }
     function stop(){ if(timer){ clearInterval(timer); timer=null; } }
     var root=document.getElementById(uid);
     if(root){

craft/src/components/sections/HeroSimple.toHtml.test.ts

@@ -0,0 +1,35 @@
+import { describe, test, expect } from 'vitest';
+import { HeroSimple } from './HeroSimple';
+
+const toHtml = (HeroSimple as any).toHtml;
+
+describe('HeroSimple.toHtml textAlign enum sink (attacker-controlled prop, not enforced at runtime)', () => {
+  test('malicious textAlign value cannot break out of the content div style attribute', () => {
+    const { html } = toHtml({
+      heading: 'Hi',
+      subtitle: 'There',
+      textAlign: 'center;"><script>alert(1)</script>',
+    }, '');
+    expect(html).not.toContain('<script>alert(1)</script>');
+    expect(html).not.toContain('center;">');
+  });
+
+  test('unrecognized textAlign value falls back to a safe default rather than being echoed raw', () => {
+    const { html } = toHtml({ heading: 'Hi', subtitle: 'There', textAlign: 'not-a-real-value' as any }, '');
+    expect(html).not.toContain('text-align:not-a-real-value');
+  });
+
+  test('valid textAlign values are preserved', () => {
+    const { html: left } = toHtml({ heading: 'Hi', subtitle: 'There', textAlign: 'left' }, '');
+    expect(left).toContain('text-align:left');
+    const { html: right } = toHtml({ heading: 'Hi', subtitle: 'There', textAlign: 'right' }, '');
+    expect(right).toContain('text-align:right');
+  });
+
+  test('normal default render is sane', () => {
+    const { html } = toHtml({ heading: 'Welcome', subtitle: 'Sub text' }, '');
+    expect(html).toContain('Welcome');
+    expect(html).toContain('Sub text');
+    expect(html).toContain('text-align:center');
+  });
+});

craft/src/components/sections/HeroSimple.tsx

@@ -229,7 +229,13 @@ HeroSimple.craft = {
     videoHtml = `<video src="${escapeAttr(safeUrl(props.bgVideo))}" autoplay muted loop playsinline style="position:absolute;top:0;left:0;width:100%;height:100%;object-fit:cover;z-index:0"></video>`;
   }
 
-  const textAlign = props.textAlign || 'center';
+  // Allowlisted -- `textAlign` is declared as a 'left'|'center'|'right' union
+  // but arrives unchecked via AI update_props / deserialized state; it is
+  // interpolated raw into the content div's style attribute below, so any
+  // other value must collapse to a known-safe default rather than being
+  // echoed into the markup.
+  const ALLOWED_TEXT_ALIGN = ['left', 'center', 'right'];
+  const textAlign = ALLOWED_TEXT_ALIGN.includes(props.textAlign as string) ? (props.textAlign as string) : 'center';
   const justifyBtn = textAlign === 'center' ? 'center' : textAlign === 'right' ? 'flex-end' : 'flex-start';
 
   const ctas = normalizeCtas(props);

craft/src/components/sections/NumberCounter.toHtml.test.ts

@@ -47,3 +47,29 @@ describe('NumberCounter.toHtml deterministic + unique scope ids (thread node id,
     expect(wrapId1).not.toBe(wrapId2);
   });
 });
+
+describe('NumberCounter.toHtml counter.number is NOT runtime-type-checked -- must be sanitized before it reaches data-target', () => {
+  test('a malicious counter.number cannot break out of the data-target attribute to inject a <script> tag', () => {
+    const malicious = [
+      { number: '150"><script>alert(1)</script>', suffix: '+', label: 'Evil' },
+    ];
+    const { html } = toHtml({ counters: malicious }, '', 'node-nc-evil1');
+    expect(html).not.toContain('<script>alert(1)</script>');
+    expect(html).not.toContain('"><script>');
+  });
+
+  test('a malicious counter.number cannot break out of the data-target attribute to inject an onmouseover handler', () => {
+    const malicious = [
+      { number: '150" onmouseover="alert(1)', suffix: '+', label: 'Evil' },
+    ];
+    const { html } = toHtml({ counters: malicious }, '', 'node-nc-evil2');
+    expect(html).not.toContain('onmouseover=');
+    expect(html).not.toMatch(/data-target="150" onmouseover/);
+  });
+
+  test('normal numeric counter.number values still render as data-target="150"', () => {
+    const normal = [{ number: 150, suffix: '+', label: 'Projects' }];
+    const { html } = toHtml({ counters: normal }, '', 'node-nc-normal');
+    expect(html).toContain('data-target="150"');
+  });
+});

craft/src/components/sections/NumberCounter.tsx

@@ -140,8 +140,20 @@ NumberCounter.craft = {
   });
 
   const countersHtml = items.map((counter, i) => {
+    // Number() coercion + escapeAttr: `counter.number` is declared `number`
+    // per-item inside an array prop, but is NOT type-checked at runtime --
+    // it arrives raw via the AI `update_props` path or a deserialized
+    // saved-state blob and was previously interpolated straight into this
+    // data-target attribute, letting a string like `150"><script>...`
+    // break out of the attribute and inject markup. Number() collapses any
+    // non-numeric value safely to NaN (then 0), and escapeAttr is kept as
+    // defense-in-depth in case Number()'s string coercion output ever
+    // contains a stray character (it can't today, but the sink should never
+    // rely solely on the coercion).
+    const numberVal = Number(counter.number);
+    const safeNumber = Number.isFinite(numberVal) ? numberVal : 0;
     return `<div style="display:flex;flex-direction:column;align-items:center;gap:8px">
-      <span id="${uid}_n${i}" data-target="${counter.number}" data-suffix="${escapeAttr(counter.suffix)}" style="font-size:${numberSize};font-weight:700;color:${numberColor};line-height:1.1;font-family:Inter,sans-serif">0${escapeHtml(counter.suffix)}</span>
+      <span id="${uid}_n${i}" data-target="${escapeAttr(String(safeNumber))}" data-suffix="${escapeAttr(counter.suffix)}" style="font-size:${numberSize};font-weight:700;color:${numberColor};line-height:1.1;font-family:Inter,sans-serif">0${escapeHtml(counter.suffix)}</span>
       <span style="font-size:15px;color:${labelColor};font-family:Inter,sans-serif;font-weight:500">${escapeHtml(counter.label)}</span>
     </div>`;
   }).join('\n    ');

craft/src/components/sections/Testimonials.toHtml.test.ts

@@ -46,3 +46,28 @@ describe('Testimonials.toHtml decorative star icons (F2.5)', () => {
     stars.forEach((tag: string) => expect(tag).toContain('aria-hidden="true"'));
   });
 });
+
+describe('Testimonials.toHtml rating aria-label sink (attacker-controlled `rating`, typed number but unchecked)', () => {
+  test('malicious rating value cannot break out of the star row aria-label attribute', () => {
+    const malicious = [
+      { quote: 'Q', name: 'N', title: 'T', rating: '5"><script>alert(1)</script>' as any },
+    ];
+    const { html } = toHtml({ testimonials: malicious, layout: 'grid' }, '');
+    expect(html).not.toContain('<script>alert(1)</script>');
+    expect(html).not.toContain('5"><script>');
+  });
+
+  test('non-numeric rating falls back to a safe numeric value', () => {
+    const malicious = [
+      { quote: 'Q', name: 'N', title: 'T', rating: 'not-a-number' as any },
+    ];
+    const { html } = toHtml({ testimonials: malicious, layout: 'grid' }, '');
+    expect(html).toMatch(/aria-label="Rating: 0 out of 5"/);
+  });
+
+  test('normal numeric rating still renders correctly', () => {
+    const { html } = toHtml({ testimonials, layout: 'grid' }, '');
+    expect(html).toContain('aria-label="Rating: 5 out of 5"');
+    expect(html).toContain('aria-label="Rating: 4 out of 5"');
+  });
+});

craft/src/components/sections/Testimonials.tsx

@@ -41,10 +41,16 @@ function renderStars(count: number, color: string): React.ReactNode {
 }
 
 function starsHtml(count: number, color: string): string {
+  // `count` is `Testimonial.rating`, typed `number` but arrives unchecked via
+  // AI update_props / deserialized state -- coerce to a real number before
+  // it's interpolated into the aria-label attribute below (both the loop
+  // comparison and the escapeAttr(String(...)) call are safe against any
+  // non-numeric/garbage value).
+  const safeCount = Number(count) || 0;
   const stars = [1, 2, 3, 4, 5].map((i) =>
-    `<i class="fa ${i <= count ? 'fa-star' : 'fa-star-o'}" style="color:${color};font-size:14px" aria-hidden="true"></i>`
+    `<i class="fa ${i <= safeCount ? 'fa-star' : 'fa-star-o'}" style="color:${color};font-size:14px" aria-hidden="true"></i>`
   ).join('');
-  return `<div style="display:flex;gap:2px;justify-content:center;margin-bottom:12px" role="img" aria-label="Rating: ${count} out of 5">${stars}</div>`;
+  return `<div style="display:flex;gap:2px;justify-content:center;margin-bottom:12px" role="img" aria-label="${escapeAttr(`Rating: ${safeCount} out of 5`)}">${stars}</div>`;
 }
 
 export const Testimonials: UserComponent<TestimonialsProps> = ({