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2025-02-09
Bug Report: Reflected XSS on chat.deepseek.com
Domain: chat.deepseek.com
Vulnerability Type: Reflected Cross-Site Scripting (XSS)
Severity: High
Description:
A reflected XSS vulnerability was discovered on chat.deepseek.com. The issue arises when requesting AI-generated HTML, CSS, or JS code that can be executed. When the generated code includes a script to access document.cookie, it inadvertently exposes cookies from cdn.deepseek.com. This allows an attacker to inject malicious scripts and steal sensitive user data, such as session cookies.
Proof of Concept (PoC):
- Visit chat.deepseek.com and request the AI to generate the following HTML+JS code:
<html> <body> <button onclick="alert(document.cookie)">Click Me</button> </body> </html>
- Click the “Run” button in the AI interface.
- A new page is created with a “Click Me” button.
- Clicking the button executes
alert(document.cookie), exposing authentication cookies.
**Impact:**
- Attackers can steal session cookies and impersonate users.
- Potential for account hijacking and data theft.
- Users’ sensitive information may be compromised if exploited.
**Suggested Fixes:**
- Sanitize user input before rendering HTML/JavaScript.
- Implement Content Security Policy (CSP) to block inline JavaScript execution.
- Restrict AI-generated code execution to a secure sandbox environment.
**What Undercode Say:**
Reflected XSS vulnerabilities remain a critical threat to web applications, especially those leveraging AI-generated content. The ability to inject malicious scripts through user input highlights the importance of robust input sanitization and secure coding practices. Below are some Linux and cybersecurity commands and tools that can help mitigate such vulnerabilities:
1. **Input Sanitization with OWASP ZAP:**
Use OWASP ZAP to test for XSS vulnerabilities:
zap-cli quick-scan -s xss http://example.com
2. **Content Security Policy (CSP) Implementation:**
Add a CSP header to your web server configuration (e.g., Apache):
Header set Content-Security-Policy "default-src 'self'; script-src 'self';"
3. **Sandboxing with Docker:**
Run AI-generated code in a Docker container to isolate execution:
docker run --rm -v /path/to/code:/code python:3.9 python /code/script.py
4. **Cookie Security with Secure and HttpOnly Flags:**
Ensure cookies are set with Secure and HttpOnly flags in your web application:
[javascript]
res.setHeader(‘Set-Cookie’, ‘sessionId=12345; Secure; HttpOnly’);
[/javascript]
5. **Automated Scanning with Nikto:**
Scan for vulnerabilities using Nikto:
nikto -h http://example.com
6. **Log Analysis with Grep:**
Monitor logs for suspicious activity:
grep "XSS" /var/log/apache2/access.log
7. **Web Application Firewall (WAF) Configuration:**
Use ModSecurity to block XSS attacks:
sudo apt-get install libapache2-mod-security2 sudo a2enmod security2
8. **Secure Coding Practices:**
Use libraries like DOMPurify to sanitize HTML:
[javascript]
const clean = DOMPurify.sanitize(dirty);
[/javascript]
9. **Penetration Testing with Metasploit:**
Test for XSS vulnerabilities using Metasploit:
msfconsole use auxiliary/scanner/http/xss set RHOSTS example.com run
10. **Monitoring with Fail2Ban:**
Protect against brute-force attacks:
sudo apt-get install fail2ban sudo systemctl start fail2ban
By implementing these measures, developers and security professionals can significantly reduce the risk of XSS vulnerabilities. Regular security audits, penetration testing, and adherence to secure coding practices are essential to maintaining a robust defense against cyber threats.
For further reading, refer to:
Stay vigilant and prioritize security in every layer of your application.
References:
Hackers Feeds, Undercode AI
