CVE-2024-4066
📋 TL;DR
A critical stack-based buffer overflow vulnerability in Tenda AC8 routers allows remote attackers to execute arbitrary code by manipulating specific parameters in the fromAdvSetMacMtuWan function. This affects Tenda AC8 routers running firmware version 16.03.34.09. Attackers can exploit this without authentication to potentially take full control of affected devices.
💻 Affected Systems
- Tenda AC8
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise leading to persistent backdoor installation, network traffic interception, lateral movement to other devices, and participation in botnets.
Likely Case
Remote code execution allowing attackers to modify router settings, intercept traffic, or use the device as a foothold for further attacks.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering and network segmentation.
🎯 Exploit Status
Exploit details are publicly available on GitHub. The vulnerability requires no authentication and has straightforward exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None available
Restart Required: Yes
Instructions:
1. Check Tenda's official website for firmware updates. 2. If an update is available, download the firmware file. 3. Log into the router's web interface. 4. Navigate to System Tools > Firmware Upgrade. 5. Upload and install the new firmware. 6. Reboot the router after installation.
🔧 Temporary Workarounds
Block Access to Vulnerable Endpoint
linuxUse firewall rules to block access to the /goform/AdvSetMacMtuWan endpoint
iptables -A INPUT -p tcp --dport 80 -m string --string "/goform/AdvSetMacMtuWan" --algo bm -j DROP
iptables -A INPUT -p tcp --dport 443 -m string --string "/goform/AdvSetMacMtuWan" --algo bm -j DROP
Disable Remote Management
allTurn off remote management features to prevent external exploitation
🧯 If You Can't Patch
- Isolate affected routers in a separate VLAN with strict firewall rules limiting inbound and outbound traffic
- Implement network monitoring for unusual traffic patterns or attempts to access the vulnerable endpoint
🔍 How to Verify
Check if Vulnerable:
Check the router's firmware version via the web interface at System Status > Firmware VersionCheck Version:
curl -s http://router-ip/goform/getStatus | grep versionVerify Fix Applied:
Verify firmware version has changed from 16.03.34.09 to a newer version📡 Detection & Monitoring
Log Indicators:
- Multiple POST requests to /goform/AdvSetMacMtuWan with unusually long parameter values
- Router crash/reboot logs following web interface access
Network Indicators:
- Unusual outbound connections from router IP
- Traffic spikes to/from router on ports 80/443
SIEM Query:
source="router_logs" AND (url="/goform/AdvSetMacMtuWan" AND (param="wanMTU" OR param="wanSpeed" OR param="cloneType" OR param="mac" OR param="serviceName" OR param="serverName"))🔗 References
- https://github.com/abcdefg-png/IoT-vulnerable/blob/main/Tenda/AC8/fromAdvSetMacMtuWan.md
- https://vuldb.com/?ctiid.261792
- https://vuldb.com/?id.261792
- https://vuldb.com/?submit.316495
- https://github.com/abcdefg-png/IoT-vulnerable/blob/main/Tenda/AC8/fromAdvSetMacMtuWan.md
- https://vuldb.com/?ctiid.261792
- https://vuldb.com/?id.261792
- https://vuldb.com/?submit.316495
