API6:2023 Demo

// POST /api/Feedbacks/
async function submitFeedback(req, res) {
  const { captchaId, captcha, comment, rating } = req.body;

  // Validate CAPTCHA answer
  const captchaRecord = await getCaptcha(captchaId);
  if (captchaRecord.answer !== captcha) {
    return res.status(400).json({ error: "Invalid CAPTCHA" });
  }

  // ⚠️ VULNERABILITY: CAPTCHA is validated but NEVER invalidated
  // The same captchaId + answer can be replayed indefinitely
  // No rate limiting applied

  const feedback = await createFeedback({ comment, rating });
  return res.status(201).json({ success: true, id: feedback.id });
}

// POST /api/Feedbacks/
async function submitFeedback(req, res) {
  const { captchaId, captcha, comment, rating } = req.body;
  // Validate CAPTCHA answer
  const captchaRecord = await getCaptcha(captchaId);
  if (captchaRecord.answer !== captcha) {
    return res.status(400).json({ error: "Invalid CAPTCHA" });
  }
+ // ✅ FIX 1: Single-use CAPTCHA enforcement
+ if (captchaRecord.used) {
+   return res.status(403).json({
+     error: "CAPTCHA already used. Request a new one."
+   });
+ }
+ await markCaptchaAsUsed(captchaId);
+ // ✅ FIX 2: Rate limiting (max 3 requests per minute)
+ if (!checkRateLimit(req.sessionId)) {
+   return res.status(429).json({
+     error: "Rate limit exceeded. Try again later."
+   });
+ }
  const feedback = await createFeedback({ comment, rating });
  return res.status(201).json({ success: true, id: feedback.id });
}