CVE-2023-1257
📋 TL;DR
An attacker with physical access to Moxa UC Series devices can restart them, access the BIOS, modify boot parameters to gain terminal access, and then create new administrative users to take full control. This affects organizations using these industrial control devices in physically accessible locations. The vulnerability requires physical access but leads to complete system compromise.
💻 Affected Systems
- Moxa UC Series devices
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device takeover allowing attacker to modify configurations, install malware, disrupt industrial operations, or use device as pivot point into industrial networks.
Likely Case
Unauthorized administrative access leading to configuration changes, data theft, or disruption of industrial processes.
If Mitigated
Limited impact if devices are in physically secure locations with BIOS password protection and boot security enabled.
🎯 Exploit Status
Exploitation requires physical access to device ports and basic BIOS/boot manipulation knowledge. No authentication needed once physical access obtained.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Firmware version 1.8 or later
Vendor Advisory: https://www.moxa.com/en/support/product-support/security-advisory/moxa-uc-series-devices-bios-access-vulnerability
Restart Required: Yes
Instructions:
1. Download latest firmware from Moxa support site. 2. Backup device configuration. 3. Upload firmware via web interface or console. 4. Apply firmware update. 5. Restart device. 6. Restore configuration if needed.
🔧 Temporary Workarounds
Physical Security Controls
allSecure devices in locked cabinets or restricted access areas to prevent physical tampering.
BIOS Password Protection
allEnable BIOS password if supported by device to prevent unauthorized BIOS access.
🧯 If You Can't Patch
- Implement strict physical access controls to device locations
- Enable BIOS password protection and secure boot options if available
- Monitor device physical access logs and tamper indicators
- Segment industrial network to limit lateral movement potential
🔍 How to Verify
Check if Vulnerable:
Check device firmware version via web interface (System > System Information) or console. Versions below 1.8 are vulnerable.Check Version:
ssh admin@device_ip 'cat /etc/version' or check web interface System InformationVerify Fix Applied:
Confirm firmware version is 1.8 or higher and test that BIOS access requires authentication.📡 Detection & Monitoring
Log Indicators:
- Unexpected device restarts
- BIOS access attempts
- New user creation in authentication logs
- Configuration changes without authorization
Network Indicators:
- Unusual network traffic from industrial devices
- New administrative connections from unexpected locations
SIEM Query:
source="moxa-device" AND (event="restart" OR event="bios_access" OR event="user_added")