CVE-2024-28211
📋 TL;DR
CVE-2024-28211 is a critical vulnerability in nGrinder versions before 3.5.9 that allows remote attackers to execute arbitrary code by connecting to malicious JMX/RMI servers. This affects all nGrinder deployments using default configurations, potentially giving attackers full control over affected systems.
💻 Affected Systems
- nGrinder
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote unauthenticated attacker gains complete system control, executes arbitrary code, installs malware, and compromises the entire infrastructure.
Likely Case
Attackers exploit exposed nGrinder instances to execute malicious code, steal credentials, and pivot to internal networks.
If Mitigated
With proper network segmentation and access controls, exploitation is limited to isolated test environments with minimal business impact.
🎯 Exploit Status
Exploitation leverages standard Java RMI deserialization attacks, which are well-documented and easily weaponized.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.5.9
Vendor Advisory: https://cve.naver.com/detail/cve-2024-28211.html
Restart Required: Yes
Instructions:
1. Download nGrinder 3.5.9 or later from official sources. 2. Stop the nGrinder service. 3. Replace the existing installation with the patched version. 4. Restart the nGrinder service. 5. Verify the version is 3.5.9 or higher.
🔧 Temporary Workarounds
Network Isolation
linuxRestrict network access to nGrinder JMX/RMI ports (default 16001, 16002) using firewall rules.
iptables -A INPUT -p tcp --dport 16001 -j DROP
iptables -A INPUT -p tcp --dport 16002 -j DROP
Disable JMX/RMI
allConfigure nGrinder to disable JMX/RMI connections by modifying startup parameters.
Add -Dcom.sun.management.jmxremote=false to nGrinder startup script
🧯 If You Can't Patch
- Implement strict network segmentation to isolate nGrinder instances from production networks
- Deploy application firewalls or WAF rules to block suspicious RMI traffic patterns
🔍 How to Verify
Check if Vulnerable:
Check nGrinder version via web interface or configuration files. If version is below 3.5.9, the system is vulnerable.Check Version:
Check nGrinder web interface or examine version.txt in installation directoryVerify Fix Applied:
Confirm nGrinder version is 3.5.9 or higher and test that JMX/RMI ports are not accepting unauthorized connections.📡 Detection & Monitoring
Log Indicators:
- Unexpected RMI connection attempts
- Java deserialization errors in nGrinder logs
- Unauthorized JMX authentication attempts
Network Indicators:
- Unusual traffic to nGrinder JMX/RMI ports (16001, 16002)
- RMI registry lookups from unexpected sources
SIEM Query:
source="ngrinder.log" AND ("RMI" OR "JMX") AND ("error" OR "unauthorized" OR "deserialization")