XSS

Security Level - Low

DOM-Based XSS

Choose English language and intercept the request in Burp.

Notice that the choice is being passed to the document.write() sink

Exploit

Exploiting this requires escaping <option value='English'>English</option>.

Submit domain/DVWA/vulnerabilities/xss_d/?default='><script>alert(1)</script>

Result

Reflected XSS

In order to exploit this, we add a random value, submit it and then check the page source:

We notice that the value is reflected between <pre></pre> tags.

We can now submit <script>alert(1)</script>.

Result

Stored XSS

Input a random value to the Name and Message fields and check how the values are stored.

For this stored XSS to work, we can try to add <img src=x onerror=alert(1)> in the message box.

Result