CVE-2021-20146
📋 TL;DR
This vulnerability involves an unprotected SSH private key present on Gryphon devices that could allow attackers to gain root access to Gryphon's development and infrastructure servers. The exposed key could be used to authenticate to AWS-hosted development servers. This affects Gryphon device owners and potentially Gryphon's internal development infrastructure.
💻 Affected Systems
- Gryphon devices
📦 What is this software?
Gryphon Tower Firmware by Gryphonconnect
⚠️ Risk & Real-World Impact
Worst Case
Attackers gain root access to Gryphon's development servers, potentially compromising source code, customer data, and enabling further attacks against production systems or customers.
Likely Case
Attackers use the exposed key to access development infrastructure, steal intellectual property, and potentially pivot to other systems in Gryphon's network.
If Mitigated
With proper key rotation and access controls, impact is limited to potential historical exposure of development systems with no current access.
🎯 Exploit Status
Exploitation requires extracting the private key from the device and using it to authenticate to Gryphon's servers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Firmware updates released by Gryphon
Vendor Advisory: https://www.tenable.com/security/research/tra-2021-51
Restart Required: Yes
Instructions:
1. Update Gryphon device firmware to latest version. 2. Ensure the device restarts after update. 3. Verify SSH keys have been rotated on backend servers.
🔧 Temporary Workarounds
Disable SSH access from affected devices
linuxBlock SSH connections from Gryphon devices to development servers
iptables -A INPUT -s [gryphon_device_ip] -p tcp --dport 22 -j DROP
Rotate SSH keys on servers
linuxGenerate new SSH key pairs and replace the compromised key
ssh-keygen -t rsa -b 4096 -f /etc/ssh/ssh_host_rsa_key
systemctl restart sshd
🧯 If You Can't Patch
- Network segmentation: Isolate Gryphon devices from accessing development servers
- Monitor for SSH authentication attempts using the compromised key
🔍 How to Verify
Check if Vulnerable:
Check if Gryphon device contains the exposed SSH private key in firmware or file systemCheck Version:
Check device firmware version in Gryphon admin interfaceVerify Fix Applied:
Verify new firmware version and check that SSH key authentication to Gryphon servers fails with old key📡 Detection & Monitoring
Log Indicators:
- Failed SSH authentication attempts
- Successful SSH logins from unexpected sources
- SSH key-based authentication logs
Network Indicators:
- SSH connections from Gryphon devices to development servers
- Unusual SSH traffic patterns
SIEM Query:
source="auth.log" AND "sshd" AND ("Accepted publickey" OR "Failed publickey")