CVE-2020-21933
📋 TL;DR
Motorola CX2 router firmware versions including Build 20190508 Rel.97360n store admin passwords and private keys in log files that are included in tar packages. This allows attackers with access to these log files to gain administrative access and potentially compromise the router. Only users of Motorola CX2 routers with vulnerable firmware are affected.
💻 Affected Systems
- Motorola CX2 router
📦 What is this software?
Cx2 Firmware by Motorola
⚠️ Risk & Real-World Impact
Worst Case
Complete router compromise allowing attackers to intercept traffic, modify configurations, install malware, and pivot to internal networks.
Likely Case
Unauthorized administrative access to the router leading to network monitoring, DNS hijacking, or credential theft.
If Mitigated
Limited impact if logs are properly secured and access controls prevent unauthorized log retrieval.
🎯 Exploit Status
Exploitation requires access to log tar packages, which may be accessible via web interface or file disclosure vulnerabilities.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: No official vendor advisory found
Restart Required: No
Instructions:
No official patch available. Check Motorola support for firmware updates or consider router replacement.
🔧 Temporary Workarounds
Disable log tar generation
allPrevent creation of log tar packages that contain sensitive data
Router-specific configuration commands unavailable - check web interface for logging settings
Secure log access
allRestrict access to log files and tar packages
Router-specific configuration commands unavailable - use access control lists and authentication
🧯 If You Can't Patch
- Isolate router from critical networks and implement network segmentation
- Monitor for unauthorized access attempts and review router logs regularly
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via web interface or SSH. If version is CX 1.0.2 Build 20190508 Rel.97360n or earlier, assume vulnerable.Check Version:
Router-specific command unavailable - use web interface at http://router-ip or check documentationVerify Fix Applied:
Check if newer firmware version is installed and verify log tar packages no longer contain sensitive credentials.📡 Detection & Monitoring
Log Indicators:
- Unauthorized access to log files or tar packages
- Failed authentication attempts followed by successful admin login
Network Indicators:
- Unusual router configuration changes
- DNS or routing modifications from router
SIEM Query:
Example: (source_ip=router_ip AND (event_type="file_access" AND file_path="*.tar") OR (auth_result="success" AND user="admin" AND source_ip!=trusted_ip))