XML External Entity

The video tutorial discusses the risks associated with uploading malicious XML files, which can exploit vulnerabilities in code or dependencies to execute harmful actions like code execution and data theft. It highlights the dangers of allowing XML file uploads that can access local files, such as password files. The tutorial also provides countermeasures to mitigate these risks, including server-side whitelisting, using web application firewalls, conducting code reviews, and avoiding serialization of sensitive data on the client side.

What role does a web application firewall (WAF) play in preventing XML file upload attacks?

Why is it recommended to avoid serialization of sensitive data at the client side?