CVE-2021-22767
📋 TL;DR
This vulnerability in Schneider Electric PowerLogic EGX devices allows attackers to send specially crafted HTTP packets that bypass input validation, potentially causing denial of service or remote code execution. It affects PowerLogic EGX100 versions 3.0.0+ and all versions of PowerLogic EGX300, which are industrial energy management gateways.
💻 Affected Systems
- PowerLogic EGX100
- PowerLogic EGX300
📦 What is this software?
Powerlogic Egx100 Firmware by Schneider Electric
Powerlogic Egx300 Firmware by Schneider Electric
⚠️ Risk & Real-World Impact
Worst Case
Remote unauthenticated attacker gains full control of the device, executes arbitrary code, and potentially pivots to other industrial control systems.
Likely Case
Denial of service causing device reboot or malfunction, disrupting energy monitoring and management functions.
If Mitigated
Attack blocked at network perimeter, minimal impact with proper segmentation and monitoring.
🎯 Exploit Status
CVSS 9.8 indicates critical severity with network attack vector and no privileges required.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check vendor advisory for specific patched versions
Vendor Advisory: http://download.schneider-electric.com/files?p_Doc_Ref=SEVD-2021-159-03
Restart Required: Yes
Instructions:
1. Download firmware update from Schneider Electric portal. 2. Backup device configuration. 3. Apply firmware update following vendor instructions. 4. Reboot device. 5. Verify updated version.
🔧 Temporary Workarounds
Network Segmentation
allIsolate EGX devices in dedicated VLANs with strict firewall rules limiting HTTP access to authorized management stations only.
Access Control Lists
allImplement network ACLs to restrict HTTP traffic to EGX devices from specific trusted IP addresses.
🧯 If You Can't Patch
- Implement strict network segmentation with firewall rules blocking all unnecessary HTTP traffic to affected devices.
- Deploy intrusion detection systems monitoring for anomalous HTTP packets targeting EGX devices.
🔍 How to Verify
Check if Vulnerable:
Check device firmware version via web interface or CLI. If EGX100 is version 3.0.0+ or EGX300 is any version, device is vulnerable.Check Version:
Check via web interface at http://<device-ip>/ or consult device documentation for CLI version check.Verify Fix Applied:
After patching, verify firmware version is updated to version specified in vendor advisory.📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP request patterns to EGX device web interface
- Device reboot logs without scheduled maintenance
Network Indicators:
- Malformed HTTP packets targeting EGX device ports (typically 80/443)
- Unusual outbound connections from EGX devices
SIEM Query:
source_ip=* AND dest_ip=<EGX_IP> AND (http_method=* AND http_uri contains unusual_patterns)