CVE-2021-34588
📋 TL;DR
This vulnerability in Bender/ebee Charge Controllers allows attackers to access unprotected data exports after device reboot. The backup export feature uses a random key that resets to empty after reboot, leaving data exposed. This affects users of vulnerable charge controller versions.
💻 Affected Systems
- Bender/ebee Charge Controllers
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers could extract sensitive configuration data, operational logs, or credentials from charge controllers, potentially enabling further attacks on charging infrastructure or energy management systems.
Likely Case
Unauthorized access to backup data containing configuration settings, potentially revealing network configurations or operational parameters.
If Mitigated
With proper network segmentation and access controls, impact is limited to data exposure without enabling further system compromise.
🎯 Exploit Status
Exploitation requires access to the device's web interface or API after reboot when the key is empty.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not specified in provided references
Vendor Advisory: https://cert.vde.com/en/advisories/VDE-2021-047
Restart Required: Yes
Instructions:
1. Contact Bender for updated firmware. 2. Apply firmware update following vendor instructions. 3. Restart device to activate fix.
🔧 Temporary Workarounds
Manual Key Reset After Reboot
allManually set the export key after each device reboot to protect data exports
Disable Remote Backup Access
allRestrict network access to backup export functionality
🧯 If You Can't Patch
- Implement strict network segmentation to isolate charge controllers from untrusted networks
- Monitor for unauthorized access attempts to backup export endpoints
🔍 How to Verify
Check if Vulnerable:
Check if backup export is accessible without authentication after device rebootCheck Version:
Check device web interface or contact vendor for version informationVerify Fix Applied:
Verify backup export requires authentication even after device reboot📡 Detection & Monitoring
Log Indicators:
- Unauthorized access to backup export endpoints
- Multiple failed authentication attempts to backup functions
Network Indicators:
- Unusual traffic to backup export endpoints
- Data extraction patterns from charge controllers
SIEM Query:
source_ip='charge_controller' AND (uri CONTAINS '/backup' OR uri CONTAINS '/export') AND status_code=200