CVE-2023-25218
📋 TL;DR
CVE-2023-25218 is a critical stack overflow vulnerability in Tenda AC5 routers that allows attackers to cause denial of service or execute arbitrary code by sending crafted payloads to the form_fast_setting_wifi_set function. This affects Tenda AC5 router users running vulnerable firmware versions. Attackers can potentially gain full control of affected devices.
💻 Affected Systems
- Tenda AC5 router
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, network infiltration, and persistent backdoor installation.
Likely Case
Denial of service causing router crashes and network disruption, with potential for limited code execution.
If Mitigated
Isolated network impact if device is behind firewall with strict inbound filtering.
🎯 Exploit Status
Public GitHub repository contains exploit details and likely proof-of-concept code. Attack requires sending crafted HTTP requests to vulnerable endpoint.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Tenda website for latest firmware > V15.03.06.28
Vendor Advisory: https://www.tenda.com.cn/security
Restart Required: Yes
Instructions:
1. Log into Tenda router admin interface. 2. Navigate to System Tools > Firmware Upgrade. 3. Download latest firmware from Tenda website. 4. Upload and install firmware. 5. Reboot router.
🔧 Temporary Workarounds
Disable remote management
allPrevent external access to router admin interface
Login to router > System Tools > Remote Management > Disable
Network segmentation
allIsolate router management interface from untrusted networks
Configure firewall rules to block WAN access to router admin port (typically 80/443)
🧯 If You Can't Patch
- Place router behind dedicated firewall with strict inbound filtering
- Disable WiFi functionality if not required
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface under System Status or Firmware Upgrade sectionCheck Version:
Login to router web interface and check System Status pageVerify Fix Applied:
Verify firmware version is updated to latest release from Tenda📡 Detection & Monitoring
Log Indicators:
- Multiple HTTP POST requests to /goform/fast_setting_wifi_set
- Router crash/reboot logs
- Unusual outbound connections from router
Network Indicators:
- HTTP traffic to router admin interface with large payloads
- Router becoming unresponsive
SIEM Query:
source="router_logs" AND (uri="/goform/fast_setting_wifi_set" OR message="crash" OR message="reboot")