CVE-2025-3699
📋 TL;DR
CVE-2025-3699 is a critical authentication bypass vulnerability affecting multiple Mitsubishi Electric air conditioning control systems. Unauthenticated remote attackers can gain unauthorized access to control HVAC systems, tamper with firmware, and access sensitive information. All listed Mitsubishi Electric G-series, GB-series, AE-series, EW-series, TE-series, TW-series, and CMS-RMD-J products are affected.
💻 Affected Systems
- G-50
- G-50-W
- G-50A
- GB-50
- GB-50A
- GB-24A
- G-150AD
- AG-150A-A
- AG-150A-J
- GB-50AD
- GB-50ADA-A
- GB-50ADA-J
- EB-50GU-A
- EB-50GU-J
- AE-200J
- AE-200A
- AE-200E
- AE-50J
- AE-50A
- AE-50E
- EW-50J
- EW-50A
- EW-50E
- TE-200A
- TE-50A
- TW-50A
- CMS-RMD-J
⚠️ 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 compromise of building HVAC systems leading to physical damage, environmental manipulation, data exfiltration, and potential firmware tampering enabling persistent backdoors.
Likely Case
Unauthorized control of air conditioning systems causing operational disruption, energy waste, and access to sensitive configuration data.
If Mitigated
Limited impact with proper network segmentation and access controls preventing external access to vulnerable systems.
🎯 Exploit Status
Authentication bypass vulnerability typically requires minimal technical skill to exploit once details are known. No public exploit code identified yet.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Contact Mitsubishi Electric for specific firmware updates
Vendor Advisory: https://www.mitsubishielectric.com/psirt/vulnerability/pdf/2025-004_en.pdf
Restart Required: Yes
Instructions:
1. Contact Mitsubishi Electric support for firmware updates specific to your model
2. Download the firmware update from authorized sources
3. Follow vendor instructions for firmware update procedure
4. Verify successful update and system functionality
🔧 Temporary Workarounds
Network Segmentation
allIsolate HVAC control systems from general network and internet access
Access Control Lists
allImplement strict firewall rules to limit access to HVAC systems
🧯 If You Can't Patch
- Segment HVAC systems on isolated network VLAN with no internet access
- Implement strict firewall rules allowing only necessary management traffic from authorized IPs
🔍 How to Verify
Check if Vulnerable:
Check device model against affected products list. If using any listed model, assume vulnerable.Check Version:
Check firmware version through device management interface or contact vendorVerify Fix Applied:
Contact Mitsubishi Electric to verify if specific firmware version for your model addresses CVE-2025-3699📡 Detection & Monitoring
Log Indicators:
- Unauthorized access attempts to HVAC management interfaces
- Unexpected configuration changes to HVAC systems
- Firmware update attempts from unauthorized sources
Network Indicators:
- Unusual traffic patterns to HVAC control ports
- External IP addresses accessing internal HVAC systems
- Protocol anomalies in HVAC communication
SIEM Query:
source="HVAC_controller" AND (event_type="authentication_failure" OR event_type="configuration_change")