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How the CVE Works:
The vulnerability in Lumi H5P-Nodejs-library (before v9.3.3) arises due to insufficient input sanitization of plain text strings. The library fails to apply `sanitizeHtml()` on user-supplied plain text inputs, allowing attackers to inject malicious JavaScript payloads. When rendered in the frontend, unsanitized text executes arbitrary scripts in the victim’s browser, leading to Cross-Site Scripting (XSS). This flaw affects applications using the library to process untrusted content, such as dynamic H5P educational modules.
DailyCVE Form:
Platform: H5P-Nodejs-library
Version: <9.3.3
Vulnerability: XSS
Severity: Moderate
Date: May 11, 2025
What Undercode Say:
Exploitation:
- Attacker crafts a malicious H5P module with embedded
<script>alert(1)</script>.
2. Victim loads the module, triggering script execution.
3. Steal cookies via `document.cookie` exfiltration.
Protection:
1. Update to H5P-Nodejs-library v9.3.3+.
2. Manually sanitize inputs using `DOMPurify`:
import DOMPurify from 'dompurify'; const cleanText = DOMPurify.sanitize(userInput);
3. Implement CSP headers:
Content-Security-Policy: default-src 'self'; script-src 'unsafe-inline' 'self'
Detection:
1. Scan dependencies for vulnerable versions:
npm audit | grep "h5p-nodejs-library"
2. Test XSS payloads in user-input fields:
<img src=x onerror=alert(1)>
Mitigation Code:
// Patch for legacy versions:
const sanitizeHtml = require('sanitize-html');
h5pInstance.setText = (text) => {
this.text = sanitizeHtml(text);
};
Analytics:
- Attack Vector: DOM-based XSS via untrusted text.
- Impact: Session hijacking, phishing.
- Affected Users: Educators/students using H5P modules.
References:
Sources:
Reported By: github.com
Extra Source Hub:
Undercode
