CVE-2021-47709
📋 TL;DR
The COMMAX Smart Home System has an unauthenticated configuration modification vulnerability that allows attackers to change system settings and cause denial-of-service. Attackers can send malformed requests to the setconf endpoint without authentication. This affects users of COMMAX Smart Home systems with vulnerable versions.
💻 Affected Systems
- COMMAX Smart Home System
- COMMAX Ruvie CCTV Bridge DVR Service
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to reconfigure security settings, disable security features, and cause permanent denial-of-service requiring physical reset.
Likely Case
Temporary denial-of-service disrupting smart home functionality and potential unauthorized configuration changes to security cameras or access controls.
If Mitigated
Limited impact if network segmentation prevents external access, though internal threats could still exploit the vulnerability.
🎯 Exploit Status
Exploit code is publicly available on Exploit-DB and other sources, making exploitation trivial for attackers with network access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Specific version not documented in public sources
Vendor Advisory: https://www.commax.com
Restart Required: Yes
Instructions:
1. Contact COMMAX support for latest firmware updates. 2. Download and apply firmware patch from vendor portal. 3. Restart the smart home system to apply changes. 4. Verify the setconf endpoint now requires authentication.
🔧 Temporary Workarounds
Network Segmentation
allIsolate COMMAX systems from untrusted networks and internet access
Firewall Blocking
linuxBlock access to the setconf endpoint using network firewalls
iptables -A INPUT -p tcp --dport [COMMAX_PORT] -m string --string "setconf" --algo bm -j DROP
🧯 If You Can't Patch
- Implement strict network segmentation to isolate COMMAX systems from all untrusted networks
- Deploy network intrusion detection systems to monitor for exploitation attempts on the setconf endpoint
🔍 How to Verify
Check if Vulnerable:
Attempt to access the setconf endpoint without authentication using curl: curl -X POST http://[TARGET_IP]:[PORT]/setconfCheck Version:
Check system web interface or contact COMMAX support for firmware versionVerify Fix Applied:
Verify setconf endpoint now requires authentication and rejects malformed requests📡 Detection & Monitoring
Log Indicators:
- Unauthenticated POST requests to /setconf endpoint
- Configuration change logs without user authentication
- System restart or crash logs following setconf requests
Network Indicators:
- HTTP POST requests to /setconf with malformed parameters
- Unusual traffic patterns to smart home system ports
SIEM Query:
source="commax_logs" AND (uri_path="/setconf" AND http_method="POST" AND auth_status="failed")