CVE-2021-38124
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code on Micro Focus ArcSight ESM systems without authentication. It affects all ArcSight ESM versions from 7.0.2 through 7.5, potentially compromising the entire security monitoring infrastructure.
💻 Affected Systems
- Micro Focus ArcSight Enterprise Security Manager (ESM)
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system takeover, data exfiltration, lateral movement to connected systems, and disabling of security monitoring capabilities.
Likely Case
Attacker gains full control of the ESM server, installs persistence mechanisms, and accesses sensitive security event data.
If Mitigated
Limited impact due to network segmentation, strict access controls, and immediate detection through monitoring.
🎯 Exploit Status
The vulnerability is in a command injection component (CWE-77) that can be exploited without authentication. While no public PoC exists, the high CVSS score and nature suggest weaponization is likely.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 7.6 or later
Vendor Advisory: https://portal.microfocus.com/s/article/KM000001960
Restart Required: Yes
Instructions:
1. Download ArcSight ESM version 7.6 or later from Micro Focus support portal. 2. Backup current configuration and data. 3. Apply the update following Micro Focus upgrade documentation. 4. Restart all ArcSight services. 5. Verify functionality post-upgrade.
🔧 Temporary Workarounds
Network Segmentation
allRestrict network access to ArcSight ESM servers to only trusted management networks and required client connections.
Firewall Rules
allImplement strict firewall rules to limit inbound connections to ArcSight ESM ports from authorized IP addresses only.
🧯 If You Can't Patch
- Immediately isolate ArcSight ESM servers from untrusted networks and internet access
- Implement strict network monitoring and alerting for any suspicious activity targeting ArcSight systems
🔍 How to Verify
Check if Vulnerable:
Check ArcSight ESM version via web interface or command line. Versions 7.0.2 through 7.5 are vulnerable.Check Version:
On ArcSight server: /opt/arcsight/manager/bin/arcsight versionVerify Fix Applied:
Verify ArcSight ESM version is 7.6 or later and confirm no unauthorized access or suspicious activity in logs.📡 Detection & Monitoring
Log Indicators:
- Unusual command execution in system logs
- Unauthorized access attempts to ArcSight services
- Unexpected process creation from ArcSight components
Network Indicators:
- Unusual outbound connections from ArcSight server
- Suspicious payloads in requests to ArcSight ports
- Traffic from unexpected sources to ArcSight management interfaces
SIEM Query:
source="arcsight_esm" AND (event_type="command_execution" OR process_name="suspicious" OR src_ip="untrusted_network")