CVE-2025-3531
📋 TL;DR
This vulnerability allows attackers to inject malicious scripts into YouDianCMS admin interface through the UserName or LogType parameters. When an administrator views the log page, these scripts execute in their browser context. This affects all YouDianCMS 9.5.21 installations with admin access.
💻 Affected Systems
- YouDianCMS
📦 What is this software?
Youdiancms by Youdiancms
⚠️ Risk & Real-World Impact
Worst Case
Administrator account compromise leading to full system takeover, data theft, or malware deployment across the CMS.
Likely Case
Session hijacking of admin accounts, credential theft, or defacement of admin interface.
If Mitigated
Limited to admin interface disruption with no data compromise if proper input validation is implemented.
🎯 Exploit Status
Exploit requires admin privileges. Public disclosure includes technical details making exploitation straightforward.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None available
Restart Required: No
Instructions:
No official patch available. Consider upgrading to a newer version if available or implementing workarounds.
🔧 Temporary Workarounds
Input Validation Filter
allAdd input sanitization for UserName and LogType parameters in the admin log interface
Edit /App/Tpl/Admin/Default/Log/index.html to sanitize all user inputs with htmlspecialchars() or similar functions
Content Security Policy
allImplement CSP headers to restrict script execution
Add 'Content-Security-Policy: script-src 'self'' to admin interface headers
🧯 If You Can't Patch
- Restrict admin interface access to trusted IP addresses only
- Implement web application firewall rules to block XSS payloads in UserName/LogType parameters
🔍 How to Verify
Check if Vulnerable:
Test by injecting basic XSS payloads into UserName or LogType parameters when accessing admin log interfaceCheck Version:
Check YouDianCMS version in admin dashboard or configuration filesVerify Fix Applied:
Verify that script tags and JavaScript payloads are properly escaped in the rendered HTML output📡 Detection & Monitoring
Log Indicators:
- Unusual script tags or JavaScript in UserName/LogType parameters in access logs
- Multiple failed login attempts followed by successful admin login
Network Indicators:
- HTTP requests containing script tags in UserName or LogType parameters to admin interface
SIEM Query:
source="web_logs" AND (uri_path="/App/Tpl/Admin/Default/Log/index.html" AND (query_string CONTAINS "<script>" OR query_string CONTAINS "javascript:"))