CVE-2025-3714
📋 TL;DR
This critical vulnerability allows unauthenticated remote attackers to execute arbitrary code on LCD KVM over IP Switch CL5708IM devices by exploiting a stack-based buffer overflow. Attackers can gain full control of affected devices, potentially compromising connected systems. All organizations using CL5708IM switches with firmware older than v2.2.215 are affected.
💻 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 takeover leading to lateral movement into connected servers, data exfiltration, ransomware deployment, and persistent backdoor installation across the network.
Likely Case
Device compromise allowing attackers to intercept KVM sessions, capture credentials, and pivot to connected systems for further exploitation.
If Mitigated
Limited to device compromise without lateral movement if proper network segmentation and access controls are implemented.
🎯 Exploit Status
Remote unauthenticated exploitation with low complexity makes this highly attractive to attackers. No authentication required.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v2.2.215
Vendor Advisory: https://www.twcert.org.tw/en/cp-139-10107-26b24-2.html
Restart Required: Yes
Instructions:
1. Download firmware v2.2.215 from vendor. 2. Access device web interface. 3. Navigate to firmware update section. 4. Upload new firmware file. 5. Apply update and wait for automatic restart.
🔧 Temporary Workarounds
Network Isolation
allPlace KVM switches on isolated VLAN with strict access controls
Access Restriction
linuxImplement firewall rules to restrict access to KVM switch management interface
iptables -A INPUT -p tcp --dport [KVM_PORT] -s [TRUSTED_NETWORK] -j ACCEPT
iptables -A INPUT -p tcp --dport [KVM_PORT] -j DROP
🧯 If You Can't Patch
- Immediately isolate affected devices from production networks and internet access
- Implement strict network segmentation with firewall rules blocking all unnecessary traffic to KVM switches
🔍 How to Verify
Check if Vulnerable:
Check firmware version in device web interface under System Information or via SSH if enabledCheck Version:
Check via web interface: System > Firmware InformationVerify Fix Applied:
Confirm firmware version shows v2.2.215 or higher in device management interface📡 Detection & Monitoring
Log Indicators:
- Unusual connection attempts to KVM management port
- Multiple failed login attempts followed by successful access
- Firmware version change alerts
Network Indicators:
- Unusual outbound connections from KVM device
- Traffic patterns indicating reverse shells
- Port scanning originating from KVM device
SIEM Query:
source_ip=[KVM_IP] AND (event_type="buffer_overflow" OR event_type="code_execution" OR destination_port IN [SUSPICIOUS_PORTS])