CVE-2023-51926
📋 TL;DR
YonBIP v3_23.05 contains an arbitrary file read vulnerability in the nc.bs.framework.comn.serv.CommonServletDispatcher component. This allows attackers to read sensitive files from the server filesystem without authentication. Organizations using YonBIP v3_23.05 are affected.
💻 Affected Systems
- YonBIP
📦 What is this software?
Yonbip by Yonyou
⚠️ Risk & Real-World Impact
Worst Case
Attackers could read sensitive configuration files, credentials, database connections, or other critical system files, potentially leading to full system compromise.
Likely Case
Unauthenticated attackers reading application configuration files, source code, or other sensitive data stored on the server.
If Mitigated
If proper network segmentation and access controls are in place, impact is limited to reading files within the application's accessible directories.
🎯 Exploit Status
GitHub references suggest exploit details are publicly available. Arbitrary file read vulnerabilities typically have simple exploitation paths.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://www.yonyou.com/
Restart Required: No
Instructions:
1. Check vendor advisory at yonyou.com for patches
2. Apply any available security updates
3. Monitor vendor communications for specific fix
🔧 Temporary Workarounds
Restrict Servlet Access
allConfigure web server or application firewall to block access to the vulnerable CommonServletDispatcher endpoint
# Example for Apache: RewriteRule ^/path/to/CommonServletDispatcher - [F]
# Example for Nginx: location ~ /CommonServletDispatcher { deny all; }
Network Segmentation
linuxRestrict network access to YonBIP instances to only trusted sources
# Firewall rule example: iptables -A INPUT -p tcp --dport 80 -s trusted_network -j ACCEPT
# iptables -A INPUT -p tcp --dport 80 -j DROP
🧯 If You Can't Patch
- Implement strict network access controls to limit exposure
- Deploy web application firewall with rules to detect and block file read attempts
🔍 How to Verify
Check if Vulnerable:
Test if the CommonServletDispatcher endpoint allows reading arbitrary files by attempting to access known system files through the vulnerable componentCheck Version:
Check YonBIP version in application interface or configuration filesVerify Fix Applied:
Verify the patch prevents arbitrary file reads by testing the same exploitation attempts📡 Detection & Monitoring
Log Indicators:
- Unusual file path patterns in servlet requests
- Multiple failed file access attempts
- Requests to CommonServletDispatcher with file path parameters
Network Indicators:
- HTTP requests containing file path traversal patterns
- Requests to CommonServletDispatcher endpoint
SIEM Query:
web.url:*CommonServletDispatcher* AND (web.uri:*../* OR web.uri:*..\*)