CVE-2025-3712
📋 TL;DR
CVE-2025-3712 is a heap-based buffer overflow vulnerability in LCD KVM over IP Switch CL5708IM firmware that allows unauthenticated remote attackers to cause denial-of-service. The vulnerability affects all firmware versions prior to v2.2.215. Organizations using these vulnerable KVM switches are at risk of service disruption.
💻 Affected Systems
- LCD KVM over IP Switch CL5708IM
⚠️ 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 device crash requiring physical reset, potentially disrupting access to connected servers and infrastructure.
Likely Case
Service disruption of the KVM switch, preventing remote management of connected systems until device is rebooted.
If Mitigated
Limited impact if device is behind firewall with restricted network access and proper segmentation.
🎯 Exploit Status
The vulnerability description indicates unauthenticated remote exploitation is possible, suggesting relatively straightforward attack vectors.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v2.2.215 or later
Vendor Advisory: https://www.twcert.org.tw/en/cp-139-10105-1e8b5-2.html
Restart Required: Yes
Instructions:
1. Download firmware v2.2.215 or later from vendor. 2. Access KVM web interface. 3. Navigate to firmware update section. 4. Upload new firmware file. 5. Apply update and wait for device to reboot.
🔧 Temporary Workarounds
Network Segmentation
allRestrict network access to KVM management interface using firewall rules
VLAN Isolation
allPlace KVM switches on isolated management VLAN separate from user networks
🧯 If You Can't Patch
- Implement strict network access controls to limit which IP addresses can reach the KVM management interface
- Monitor network traffic to the KVM device for unusual patterns or DoS attempts
🔍 How to Verify
Check if Vulnerable:
Check firmware version via web interface: Login > System Information > Firmware VersionCheck Version:
No CLI command available - use web interface at http://[device-ip]Verify Fix Applied:
Verify firmware version shows v2.2.215 or higher after update📡 Detection & Monitoring
Log Indicators:
- Device reboot logs
- Connection attempts to management interface
- Firmware update failures
Network Indicators:
- Unusual traffic patterns to KVM management port
- Multiple connection attempts from single source
SIEM Query:
source_ip=[KVM_IP] AND (event_type="device_reboot" OR port=80 OR port=443) AND protocol="TCP"