CVE-2021-21905
📋 TL;DR
This CVE describes a stack-based buffer overflow in the CMA readfile function of Garrett Metal Detectors iC Module CMA Version 5.0, allowing authenticated attackers to execute arbitrary code via crafted commands sent over TCP port 6877. It affects users of Garrett iC Module CMA Version 5.0 with the CMA Connect GUI client interface enabled.
💻 Affected Systems
- Garrett Metal Detectors iC Module CMA
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise leading to remote code execution, device manipulation, or data exfiltration.
Likely Case
Unauthorized access and control of the metal detector module, potentially disrupting operations.
If Mitigated
Limited impact if authentication is strong and network access is restricted, though buffer overflow risk remains.
🎯 Exploit Status
Exploitation requires authentication, but buffer overflow details are publicly disclosed in references.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not available
Vendor Advisory: Not provided in input; check Garrett Metal Detectors for updates.
Restart Required: No
Instructions:
No official patch available; rely on workarounds and risk reduction steps.
🔧 Temporary Workarounds
Restrict Network Access
allBlock TCP port 6877 at firewalls to prevent external and unauthorized internal access.
iptables -A INPUT -p tcp --dport 6877 -j DROP (Linux)
netsh advfirewall firewall add rule name="Block Port 6877" dir=in action=block protocol=TCP localport=6877 (Windows)
Disable CMA Connect Interface
allTurn off the CMA Connect GUI client interface if not required for operations.
Consult device manual or vendor for specific disable commands; may involve configuration changes.
🧯 If You Can't Patch
- Implement strict network segmentation to isolate affected devices from untrusted networks.
- Enforce strong authentication policies and monitor for unusual activity on port 6877.
🔍 How to Verify
Check if Vulnerable:
Check if Garrett iC Module CMA Version 5.0 is running and if TCP port 6877 is open and accessible.Check Version:
Consult device interface or vendor documentation; no standard command provided.Verify Fix Applied:
Verify that port 6877 is closed or access is blocked, and confirm no unauthorized connections are established.📡 Detection & Monitoring
Log Indicators:
- Unusual authentication attempts or command patterns on port 6877 logs.
Network Indicators:
- Traffic to/from TCP port 6877, especially from unexpected sources.
SIEM Query:
Example: 'source_port:6877 OR dest_port:6877' to monitor for related network events.