CVE-2023-41556
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code on affected Tenda routers via a stack overflow in the SetIpMacBind function. Attackers can exploit this by sending specially crafted HTTP requests to the vulnerable endpoint, potentially gaining full control of the device. Users of Tenda AC7, AC9, and AC5 routers with specific firmware versions are affected.
💻 Affected Systems
- Tenda AC7
- Tenda AC9
- Tenda AC5
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing persistent remote access, credential theft, network pivoting, and deployment of malware or botnets.
Likely Case
Remote code execution leading to device takeover, DNS hijacking, credential harvesting, and use as attack platform.
If Mitigated
Limited impact if device is behind firewall with restricted WAN access and proper network segmentation.
🎯 Exploit Status
Public proof-of-concept available; exploitation requires sending crafted HTTP POST request to /goform/SetIpMacBind endpoint.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Unknown
Restart Required: No
Instructions:
Check Tenda website for firmware updates; if unavailable, consider replacing affected devices.
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to router web interface
Block Vulnerable Endpoint
linuxUse firewall rules to block access to /goform/SetIpMacBind
iptables -A INPUT -p tcp --dport 80 -m string --string "/goform/SetIpMacBind" --algo bm -j DROP
iptables -A INPUT -p tcp --dport 443 -m string --string "/goform/SetIpMacBind" --algo bm -j DROP
🧯 If You Can't Patch
- Isolate affected routers in separate VLAN with strict firewall rules
- Implement network monitoring for suspicious HTTP requests to /goform/SetIpMacBind
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via web interface at 192.168.0.1 or 192.168.1.1Check Version:
curl -s http://router-ip/goform/getStatus | grep versionVerify Fix Applied:
Verify firmware version is newer than affected versions; test if /goform/SetIpMacBind endpoint responds differently📡 Detection & Monitoring
Log Indicators:
- HTTP POST requests to /goform/SetIpMacBind with abnormal parameter length
- Router crash/restart logs
Network Indicators:
- Unusual outbound connections from router
- HTTP requests with oversized parameter lists to router management interface
SIEM Query:
source="router_logs" AND uri="/goform/SetIpMacBind" AND (content_length>1000 OR parameter_length>500)