CVE-2025-25664
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code on Tenda AC8V4 routers by exploiting a stack overflow in the shareSpeed parameter. Attackers can gain full control of affected devices without authentication. All users running the vulnerable firmware version are affected.
💻 Affected Systems
- Tenda AC8V4
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise leading to persistent backdoor installation, network traffic interception, credential theft, and lateral movement to other network devices.
Likely Case
Remote code execution allowing attackers to modify router settings, intercept traffic, or use the device as a pivot point for further attacks.
If Mitigated
Limited impact if device is behind firewall with restricted WAN access and network segmentation prevents lateral movement.
🎯 Exploit Status
Public proof-of-concept exists in GitHub repository. The vulnerability requires no authentication and has a simple exploitation path.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: Yes
Instructions:
1. Check Tenda website for firmware updates
2. Download latest firmware for AC8V4
3. Access router admin interface
4. Navigate to System Tools > Firmware Upgrade
5. Upload new firmware file
6. Wait for reboot to complete
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to router web interface
Network Segmentation
allIsolate router management interface to separate VLAN
🧯 If You Can't Patch
- Replace affected router with different model or vendor
- Place router behind firewall with strict inbound rules blocking all WAN access to management interface
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface under System Status > Firmware VersionCheck Version:
Login to router web interface and navigate to System Status pageVerify Fix Applied:
Verify firmware version is no longer V16.03.34.06 after update📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to router management interface with malformed shareSpeed parameter
- Multiple failed exploit attempts
- Unexpected configuration changes
Network Indicators:
- Unusual outbound connections from router
- Traffic patterns indicating command and control communication
- Port scanning originating from router
SIEM Query:
source="router_logs" AND (uri="*shareSpeed*" OR method="POST" AND status="200" AND size>1000)