CVE-2019-5916
📋 TL;DR
CVE-2019-5916 is an Expression Language (EL) injection vulnerability in POWER EGG software that allows remote attackers to execute arbitrary code on affected servers. This vulnerability affects multiple versions of POWER EGG across various patch levels. Attackers can exploit this without authentication to gain full control of vulnerable systems.
💻 Affected Systems
- POWER EGG
📦 What is this software?
Power Egg by D Circle
Power Egg by D Circle
Power Egg by D Circle
Power Egg by D Circle
Power Egg by D Circle
Power Egg by D Circle
Power Egg by D Circle
Power Egg by D Circle
Power Egg by D Circle
Power Egg by D Circle
Power Egg by D Circle
Power Egg by D Circle
Power Egg by D Circle
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with remote code execution, allowing attackers to install malware, steal data, pivot to other systems, or disrupt operations.
Likely Case
Remote code execution leading to data theft, system takeover, or ransomware deployment on vulnerable servers.
If Mitigated
Limited impact if proper network segmentation, web application firewalls, and input validation are implemented.
🎯 Exploit Status
The vulnerability allows EL expression injection via unspecified vectors, which typically requires minimal technical skill to exploit once the vector is identified.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Apply patches beyond the affected versions listed (e.g., Ver 2.9 Patch 5 or later, Ver 2.8c Patch 6 or later, etc.)
Vendor Advisory: https://poweregg.d-circle.com/support/package/important/20190204_000780/
Restart Required: Yes
Instructions:
1. Download the appropriate patch from the vendor advisory URL. 2. Apply the patch according to vendor instructions. 3. Restart the POWER EGG service. 4. Verify the patch was applied successfully.
🔧 Temporary Workarounds
Network Segmentation
linuxRestrict access to POWER EGG servers to only trusted IP addresses and networks.
iptables -A INPUT -p tcp --dport [POWER_EGG_PORT] -s [TRUSTED_IP] -j ACCEPT
iptables -A INPUT -p tcp --dport [POWER_EGG_PORT] -j DROP
Web Application Firewall
allDeploy a WAF with rules to block EL injection attempts and suspicious input patterns.
🧯 If You Can't Patch
- Isolate affected systems in a separate network segment with strict access controls.
- Implement application-level input validation and sanitization for all user inputs.
🔍 How to Verify
Check if Vulnerable:
Check the POWER EGG version against the affected version list. If running any affected version, the system is vulnerable.Check Version:
Check the POWER EGG administration interface or configuration files for version information.Verify Fix Applied:
Verify the POWER EGG version is updated to a patched version beyond the affected ranges listed in the advisory.📡 Detection & Monitoring
Log Indicators:
- Unusual EL expression patterns in web logs
- Multiple failed injection attempts
- Unexpected system commands executed from web processes
Network Indicators:
- HTTP requests containing EL expressions or suspicious payloads
- Unusual outbound connections from POWER EGG servers
SIEM Query:
source="web_logs" AND (message="*${*" OR message="*#{" OR message="*EL expression*" OR message="*injection*" AND dest_port="[POWER_EGG_PORT]")