CVE-2024-2809
📋 TL;DR
A critical stack-based buffer overflow vulnerability in Tenda AC15 routers allows remote attackers to execute arbitrary code by manipulating the firewallEn parameter. This affects Tenda AC15 routers running firmware versions 15.03.05.18 and 15.03.20_multi. Attackers can exploit this without authentication to potentially take full control of affected devices.
💻 Affected Systems
- Tenda AC15
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, creation of persistent backdoors, lateral movement to internal networks, and botnet recruitment.
Likely Case
Device takeover for use in DDoS botnets, credential theft, or network surveillance.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering and network segmentation.
🎯 Exploit Status
Public exploit code is available in GitHub repositories. The vulnerability requires sending a specially crafted HTTP POST request to /goform/SetFirewallCfg.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None available
Restart Required: No
Instructions:
No official patch available. Vendor did not respond to disclosure. Consider replacing affected devices or implementing workarounds.
🔧 Temporary Workarounds
Block Web Interface Access
linuxRestrict access to the router's web management interface from untrusted networks
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP
Disable Remote Management
allTurn off remote management features in router settings if enabled
🧯 If You Can't Patch
- Segment affected routers on isolated VLANs with strict firewall rules
- Implement network monitoring for exploit attempts targeting /goform/SetFirewallCfg
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via web interface at 192.168.0.1 or using command: curl -s http://router-ip/ | grep -i 'firmware'Check Version:
curl -s http://192.168.0.1/ | grep -o 'Firmware Version:[^<]*'Verify Fix Applied:
No fix available to verify. Monitor for vendor firmware updates.📡 Detection & Monitoring
Log Indicators:
- HTTP POST requests to /goform/SetFirewallCfg with abnormal firewallEn parameter values
- Router crash/restart logs
Network Indicators:
- Unusual outbound connections from router IP
- Exploit traffic patterns to router management interface
SIEM Query:
source="router_logs" AND url_path="/goform/SetFirewallCfg" AND method="POST"🔗 References
- https://github.com/abcdefg-png/IoT-vulnerable/blob/main/Tenda/AC15/V1.0%20V15.03.20_multi/formSetFirewallCfg.md
- https://vuldb.com/?ctiid.257664
- https://vuldb.com/?id.257664
- https://github.com/abcdefg-png/IoT-vulnerable/blob/main/Tenda/AC15/V1.0%20V15.03.20_multi/formSetFirewallCfg.md
- https://vuldb.com/?ctiid.257664
- https://vuldb.com/?id.257664
