CVE-2025-25505
📋 TL;DR
A buffer overflow vulnerability in Tenda AC6 routers allows attackers to execute arbitrary code or cause denial of service by sending specially crafted requests to the affected function. This affects users running Tenda AC6 routers with firmware version 15.03.05.16_multi. The vulnerability is in the sub_452A4 function which handles certain callback operations.
💻 Affected Systems
- Tenda AC6
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, persistence installation, and lateral movement to connected networks.
Likely Case
Denial of service causing router crashes and network disruption, potentially requiring physical reset.
If Mitigated
Limited impact with proper network segmentation and firewall rules blocking external access to router management interfaces.
🎯 Exploit Status
Detailed exploit analysis and proof-of-concept code is publicly available in the GitHub repository. The vulnerability requires sending crafted requests to the vulnerable endpoint.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: Yes
Instructions:
1. Check Tenda's official website for firmware updates. 2. Download the latest firmware for AC6 model. 3. Access router web 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 router management interface
Network Segmentation
allIsolate router management interface to trusted network segments only
🧯 If You Can't Patch
- Replace affected routers with different models or brands
- Implement strict firewall rules blocking all external access to router management ports (typically 80, 443, 8080)
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in web interface under System Status or System Tools > Firmware Upgrade. If version is exactly 15.03.05.16_multi, the device is vulnerable.Check Version:
curl -s http://router-ip/status.asp | grep -i firmware || Check web interface manuallyVerify Fix Applied:
After updating firmware, verify the version number has changed from 15.03.05.16_multi to a newer version.📡 Detection & Monitoring
Log Indicators:
- Multiple failed requests to router management interface
- Router reboot events without user action
- Unusual traffic patterns to router IP on management ports
Network Indicators:
- Unusual HTTP POST requests to router endpoints
- Traffic patterns matching known exploit payloads
- Multiple connection attempts to router management ports from external IPs
SIEM Query:
source="router_logs" AND ("reboot" OR "crash" OR "buffer") OR dest_ip="router_ip" AND (dest_port=80 OR dest_port=443 OR dest_port=8080) AND http_method="POST" AND size>1000