CVE-2025-13445
📋 TL;DR
CVE-2025-13445 is a stack-based buffer overflow vulnerability in Tenda AC21 routers that allows remote attackers to execute arbitrary code by manipulating arguments in the /goform/SetIpMacBind endpoint. This affects organizations and individuals using vulnerable Tenda AC21 routers, potentially giving attackers full control of affected devices.
💻 Affected Systems
- Tenda AC21
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, lateral movement into internal networks, persistent backdoor installation, and data exfiltration.
Likely Case
Remote code execution allowing attackers to reconfigure routers, intercept network traffic, or use devices as botnet nodes.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering or in isolated network segments.
🎯 Exploit Status
Exploit details are publicly available on GitHub, making this easily weaponizable. The vulnerability requires no authentication.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://www.tenda.com.cn/
Restart Required: Yes
Instructions:
1. Check Tenda website for firmware updates. 2. Download latest firmware. 3. Access router admin interface. 4. Navigate to firmware upgrade section. 5. Upload and apply new firmware. 6. Reboot router.
🔧 Temporary Workarounds
Block Web Interface Access
linuxRestrict access to router web interface from untrusted networks
iptables -A INPUT -p tcp --dport 80 -s ! TRUSTED_NETWORK -j DROP
iptables -A INPUT -p tcp --dport 443 -s ! TRUSTED_NETWORK -j DROP
Disable Remote Management
allTurn off remote management features in router settings
🧯 If You Can't Patch
- Segment network to isolate vulnerable routers from critical systems
- Implement strict firewall rules to block all inbound traffic to router management interfaces
🔍 How to Verify
Check if Vulnerable:
Access router web interface, navigate to system status or about page, check firmware version matches 16.03.08.16Check Version:
curl -s http://ROUTER_IP/login/Auth | grep -i versionVerify Fix Applied:
After firmware update, verify version is different from 16.03.08.16 and test that /goform/SetIpMacBind endpoint no longer accepts malicious input📡 Detection & Monitoring
Log Indicators:
- Multiple POST requests to /goform/SetIpMacBind with unusually long parameters
- Router reboot events following suspicious web requests
- Unusual outbound connections from router IP
Network Indicators:
- Exploit traffic patterns to router management interface
- Unusual payloads in HTTP POST requests to router
- Router making unexpected external connections
SIEM Query:
source="router_logs" AND (uri="/goform/SetIpMacBind" AND content_length>1000) OR (event="reboot" AND source_ip="ROUTER_IP")