CVE-2024-53477
📋 TL;DR
JFinal CMS 5.1.0 contains a deserialization vulnerability in ApiForm.java that allows unauthenticated attackers to execute arbitrary commands on the server. This affects all systems running the vulnerable version of JFinal CMS, potentially leading to complete system compromise.
💻 Affected Systems
- JFinal CMS
📦 What is this software?
Jfinal Cms by Jflyfox
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with root-level command execution, data exfiltration, and persistent backdoor installation
Likely Case
Remote code execution leading to web shell deployment, data theft, and lateral movement within the network
If Mitigated
Limited impact if proper network segmentation and input validation are in place
🎯 Exploit Status
Exploitation requires understanding of Java deserialization attacks but no authentication
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions after 5.1.0
Vendor Advisory: https://github.com/jflyfox/jfinal_cms/releases/tag/v5.1.0
Restart Required: Yes
Instructions:
1. Upgrade to latest JFinal CMS version 2. Restart the application server 3. Verify the ApiForm.java file no longer contains vulnerable deserialization code
🔧 Temporary Workarounds
Input Validation Filter
allAdd input validation to reject serialized objects in API requests
Implement custom filter to inspect Content-Type and reject application/x-java-serialized-object
Network Restriction
allRestrict access to vulnerable API endpoints
Configure firewall/WAF to block requests to /api/form endpoints
🧯 If You Can't Patch
- Implement strict network segmentation to isolate JFinal CMS from critical systems
- Deploy web application firewall with deserialization attack detection rules
🔍 How to Verify
Check if Vulnerable:
Check if running JFinal CMS 5.1.0 and examine ApiForm.java for unsafe deserializationCheck Version:
Check JFinal CMS configuration files or admin panel for version informationVerify Fix Applied:
Verify version is updated beyond 5.1.0 and ApiForm.java no longer uses ObjectInputStream without validation📡 Detection & Monitoring
Log Indicators:
- Unusual Java deserialization errors
- Suspicious API requests to /api/form
- Unexpected process execution from web server
Network Indicators:
- HTTP POST requests with serialized Java objects
- Outbound connections from web server to unknown destinations
SIEM Query:
source="web_server" AND (uri="/api/form" OR msg="*deserialization*" OR msg="*ObjectInputStream*")