CVE-2025-56463
📋 TL;DR
Mercusys MW305R routers running firmware version 3.30 and below expose their TLS certificate private keys, allowing attackers to decrypt encrypted traffic and potentially impersonate the device. This affects all users of these specific router models with vulnerable firmware.
💻 Affected Systems
- Mercusys MW305R
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers decrypt all encrypted traffic passing through the router, perform man-in-the-middle attacks, and potentially gain administrative access to the router configuration.
Likely Case
Attackers intercept and decrypt sensitive user traffic (passwords, financial data, personal information) when targeting vulnerable routers.
If Mitigated
With proper network segmentation and monitoring, impact is limited to traffic on the vulnerable router segment.
🎯 Exploit Status
The GitHub repository contains proof-of-concept code demonstrating the vulnerability. Exploitation requires network access to the router's management interface.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version above 3.30
Vendor Advisory: Not available in provided references
Restart Required: Yes
Instructions:
1. Log into router admin interface
2. Navigate to System Tools > Firmware Upgrade
3. Check for and install latest firmware
4. Reboot router after update completes
🔧 Temporary Workarounds
Disable remote management
allPrevents external attackers from accessing the vulnerable interface
Use VPN for sensitive traffic
allEncrypt traffic end-to-end to bypass router's vulnerable TLS
🧯 If You Can't Patch
- Replace affected routers with non-vulnerable models
- Isolate vulnerable routers in separate network segments with strict firewall rules
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface and compare to affected versions (3.30 and below)Check Version:
Check via router web interface at 192.168.1.1 or 192.168.0.1Verify Fix Applied:
Confirm firmware version is above 3.30 and test TLS certificate functionality📡 Detection & Monitoring
Log Indicators:
- Unusual access to router management interface
- Multiple failed TLS handshake attempts
Network Indicators:
- Unexpected certificate changes
- SSL/TLS decryption errors
SIEM Query:
source="router_logs" AND (event="admin_login" OR event="certificate_change")