CVE-2021-44165
📋 TL;DR
A buffer overflow vulnerability in the web application of Siemens SICAM Q100 power meters allows remote attackers with engineer or admin privileges to potentially execute arbitrary code. This affects all versions before V2.41 of the POWER METER SICAM Q100 device.
💻 Affected Systems
- POWER METER SICAM Q100
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote attacker gains full control of the power meter device, potentially disrupting power monitoring/management systems or using the device as a foothold into operational technology networks.
Likely Case
Attacker with valid credentials exploits the vulnerability to execute arbitrary code on the device, compromising its integrity and potentially affecting power monitoring functions.
If Mitigated
With proper network segmentation and access controls, impact is limited to the isolated device without affecting broader operational networks.
🎯 Exploit Status
Exploitation requires valid credentials (engineer or admin privileges) and knowledge of the buffer overflow trigger.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: V2.41
Vendor Advisory: https://cert-portal.siemens.com/productcert/pdf/ssa-496292.pdf
Restart Required: Yes
Instructions:
1. Download firmware version V2.41 from Siemens support portal. 2. Follow Siemens SICAM Q100 firmware update procedure. 3. Verify successful update and restart device.
🔧 Temporary Workarounds
Network Segmentation
allIsolate SICAM Q100 devices from untrusted networks and restrict access to authorized management systems only.
Access Control Hardening
allImplement strict access controls, use strong unique credentials, and limit engineer/admin accounts to essential personnel only.
🧯 If You Can't Patch
- Implement network-level controls to restrict access to SICAM Q100 web interface to specific trusted IP addresses only.
- Monitor for suspicious activity targeting the SICAM Q100 web interface and implement compensating security controls.
🔍 How to Verify
Check if Vulnerable:
Check device firmware version via web interface or device management console.Check Version:
Check via web interface at http://[device-ip]/status or device management console.Verify Fix Applied:
Confirm firmware version is V2.41 or later via device management interface.📡 Detection & Monitoring
Log Indicators:
- Multiple failed authentication attempts followed by successful login and unusual web requests
- Buffer overflow patterns in web server logs
Network Indicators:
- Unusual traffic patterns to SICAM Q100 web interface from unexpected sources
- Exploit-like payloads in HTTP requests
SIEM Query:
source="sicam-q100-logs" AND (event_type="web_request" AND (uri_contains="overflow" OR data_length>threshold))