CVE-2025-51082
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code on Tenda AC8V4 routers by exploiting a stack-based buffer overflow in the web interface's timeZone parameter. Attackers can potentially take full control of affected devices. Only users running Tenda AC8V4 routers with firmware version V16.03.34.06 are affected.
💻 Affected Systems
- Tenda AC8V4
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, persistence installation, network traffic interception, and lateral movement to other devices on the network.
Likely Case
Router crash/reboot causing temporary network disruption, or limited code execution allowing configuration changes and credential theft.
If Mitigated
Denial of service from failed exploitation attempts or blocked by network segmentation and access controls.
🎯 Exploit Status
The GitHub reference contains technical details and likely proof-of-concept. Stack overflow vulnerabilities in embedded devices are frequently weaponized due to their reliability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: http://tenda.com
Restart Required: Yes
Instructions:
1. Check Tenda's official website for firmware updates. 2. Download the latest firmware for AC8V4. 3. Log into router admin interface. 4. Navigate to System Tools > Firmware Upgrade. 5. Upload and install the new firmware. 6. Wait for router to reboot.
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to the vulnerable web interface
Log into router admin > Advanced > System Tools > Remote Management > Disable
Change Default Admin Credentials
allReduce risk of unauthorized access to admin interface
Log into router admin > Advanced > System Tools > Modify Login Password
🧯 If You Can't Patch
- Isolate the router on a separate VLAN with strict firewall rules limiting access to management interface
- Implement network monitoring for unusual traffic patterns or exploitation attempts targeting the router
🔍 How to Verify
Check if Vulnerable:
Log into router admin interface, navigate to Advanced > System Status, check firmware version matches V16.03.34.06Check Version:
curl -s http://router-ip/goform/getStatus | grep versionVerify Fix Applied:
After firmware update, verify version no longer shows V16.03.34.06 and test that the /goform/fast_setting_wifi_set endpoint rejects malformed timeZone input📡 Detection & Monitoring
Log Indicators:
- Multiple failed POST requests to /goform/fast_setting_wifi_set
- Router crash/reboot logs
- Unusual timeZone parameter values in web logs
Network Indicators:
- Unusual HTTP POST traffic to router management interface with long timeZone parameters
- Router becoming unresponsive after specific web requests
SIEM Query:
source="router_logs" AND (url="/goform/fast_setting_wifi_set" AND timeZone LENGTH > 100) OR (event="crash" AND device="router")