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>
This commit is contained in:
2026-07-12 18:03:44 -07:00
parent 7ba91d9829
commit 591a51dcc2
45 changed files with 1039 additions and 26 deletions
@@ -0,0 +1,34 @@
import { describe, test, expect } from 'vitest';
import { Divider } from './Divider';
const toHtml = (Divider as any).toHtml;
describe('Divider.toHtml normal rendering', () => {
test('renders thickness/color into the border-top style', () => {
const { html } = toHtml({ thickness: '2px', color: '#ff0000' }, '');
expect(html).toContain('border-top:2px solid #ff0000');
});
});
describe('Divider.toHtml XSS hardening (thickness/color into style=)', () => {
test('a thickness value with an attribute-breakout string cannot escape style=""', () => {
const malicious = '1px" onmouseover="alert(1)';
const { html } = toHtml({ thickness: malicious as any, color: '#000' }, '');
// The quote must not survive unescaped -- otherwise it closes style=""
// early and "onmouseover" becomes a live, attacker-controlled attribute.
expect(html).not.toMatch(/"\s+onmouseover="/);
expect(html).not.toMatch(/style="[^"]*"[^>]*onmouseover/);
});
test('a color value with a </style><script> breakout is neutralized', () => {
const malicious = '#000</style><script>alert(1)</script>';
const { html } = toHtml({ thickness: '1px', color: malicious as any }, '');
expect(html).not.toContain('<script>alert(1)</script>');
});
test('a non-string thickness (object) does not raw-splice into style=""', () => {
const malicious = { toString: () => '1px" onmouseover="alert(1)' };
const { html } = toHtml({ thickness: malicious as any, color: '#000' }, '');
expect(html).not.toMatch(/"\s+onmouseover="/);
});
});