fastapi - 💡(How to fix) Fix 🚨 Security Vulnerability Detected: docs/en/docs/js/custom.js [1 participants]

TL;DR

To mitigate the DOM-based XSS vulnerability, ensure that user-controlled data is properly sanitized before being assigned to node.textContent or used in the children array.

Guidance

• Verify that the inputCommands variable contains only sanitized user input to prevent XSS attacks through node.textContent.
• Review the showRandomAnnouncement function to ensure that the children array does not contain user-controlled data that could lead to DOM-based XSS.
• Consider using a library or function to sanitize user input, such as encoding HTML entities, to prevent XSS vulnerabilities.
• Inspect the code for any other instances where user-controlled data is used in a similar manner, as these may also be vulnerable to DOM-based XSS.

Example

// Sanitize user input using a function to encode HTML entities
function sanitizeInput(input) {
  return input.replace(/&/g, '&')
              .replace(/</g, '&lt;')
              .replace(/>/g, '&gt;')
              .replace(/"/g, '&quot;')
              .replace(/'/g, '&#039;');
}

// Use the sanitized input
node.textContent = sanitizeInput(inputCommands);

Notes

The provided guidance assumes that the inputCommands variable and the children array can contain user-controlled data. If this is not the case, or if additional context is needed, further review of the code may be necessary.

Recommendation

Apply workaround: Sanitize user-controlled data to prevent DOM-based XSS attacks, as a patch is being generated and may not be immediately available.