The Clickstorm SEO extension for TYPO3 is vulnerable to a Cross-Site Scripting (XSS) attack due to improper encoding of user input in the backend user interface. This vulnerability allows a logged-in backend user to inject malicious scripts into the HTML context, which can then be executed in the browser of other users. The issue arises when user-supplied data is not properly sanitized before being rendered in the web page, enabling attackers to execute arbitrary JavaScript code. This can lead to session hijacking, defacement, or unauthorized actions on behalf of the victim user. The vulnerability affects multiple versions of the extension, as listed below.
DailyCVE Form:
Platform: TYPO3
Version: 6.0.0 – 9.2.0
Vulnerability: XSS
Severity: Moderate
Date: Mar 19, 2025
What Undercode Say:
Exploitation:
1. Exploit Code Example:
<script>alert('XSS');</script>
Inject this payload into user input fields in the TYPO3 backend to test for XSS.
2. Exploit Steps:
- Log in to the TYPO3 backend.
- Inject malicious script into input fields.
- Save changes and observe script execution in the frontend.
3. Exploit Impact:
- Steal session cookies.
- Redirect users to malicious sites.
- Perform actions on behalf of the user.
Protection:
1. Patch Installation:
- Upgrade to patched versions: 6.7.0, 7.4.0, 8.3.0, or 9.2.0.
2. Input Sanitization:
$sanitized_input = htmlspecialchars($user_input, ENT_QUOTES, 'UTF-8');
Use PHP’s `htmlspecialchars` to encode user input.
3. Content Security Policy (CSP):
Content-Security-Policy: default-src 'self'; script-src 'self';
Implement CSP to restrict script execution.
4. Output Encoding:
{{ user_input|e('html') }}
Use Twig’s escape filter for output encoding.
5. Regular Security Audits:
- Conduct periodic code reviews.
- Use automated tools to detect XSS vulnerabilities.
6. WAF Configuration:
- Deploy a Web Application Firewall (WAF) to filter malicious payloads.
7. User Training:
- Educate backend users about the risks of XSS.
8. Monitoring:
- Monitor logs for suspicious activity.
9. Disable Unused Features:
- Disable unnecessary backend features to reduce attack surface.
10. Security Headers:
X-Content-Type-Options: nosniff X-Frame-Options: DENY
Add security headers to mitigate XSS risks.
By following these steps, you can exploit and protect against this XSS vulnerability effectively.
References:
Reported By: https://github.com/advisories/GHSA-vmgw-24w6-9v82
Extra Source Hub:
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