CVE-2025-3241
📋 TL;DR
This XXE vulnerability in YoukeFu allows attackers to read arbitrary files from the server by exploiting XML parsing in the call center router component. It affects YoukeFu versions up to 4.2.0 and can be exploited remotely without authentication.
💻 Affected Systems
- zhangyanbo2007 youkefu
📦 What is this software?
Youkefu by Zhangyanbo2007
⚠️ Risk & Real-World Impact
Worst Case
Complete server compromise through file disclosure, potential credential theft, and lateral movement within the network.
Likely Case
Sensitive file disclosure including configuration files, credentials, and system information.
If Mitigated
Limited impact with proper XML parser hardening and network segmentation.
🎯 Exploit Status
Exploit details are publicly available and the vulnerability is straightforward to exploit.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None available
Restart Required: Yes
Instructions:
1. Check for official patch from YoukeFu developers
2. If patch available, download and apply
3. Restart YoukeFu service
4. Verify fix is working
🔧 Temporary Workarounds
Disable XXE in XML parser
allConfigure XML parser to disable external entity processing
Modify Java XML parser configuration to set: FEATURE_SECURE_PROCESSING = true, DISALLOW_DOCTYPE_DECL = true
Input validation and sanitization
allAdd validation to reject XML containing external entity references
Implement input filtering for routercontent parameter to block XXE patterns
🧯 If You Can't Patch
- Implement WAF rules to block XXE payloads in HTTP requests
- Network segmentation to isolate YoukeFu instances from sensitive systems
🔍 How to Verify
Check if Vulnerable:
Test with XXE payload: <?xml version="1.0"?><!DOCTYPE root [<!ENTITY test SYSTEM 'file:///etc/passwd'>]><root>&test;</root> sent to routercontent parameterCheck Version:
Check YoukeFu version in admin interface or application.propertiesVerify Fix Applied:
Attempt XXE exploitation after applying fixes - should return error or sanitized output📡 Detection & Monitoring
Log Indicators:
- XML parsing errors
- File access attempts in logs
- Unusual XML content in routercontent parameter
Network Indicators:
- HTTP requests containing XXE payloads to CallCenterRouterController endpoints
SIEM Query:
http.uri:"*CallCenterRouterController*" AND http.param:"*routercontent*" AND (content:"<!ENTITY" OR content:"SYSTEM 'file://" OR content:"DOCTYPE")