CVE-2024-3907
📋 TL;DR
This critical vulnerability in Tenda AC500 routers allows remote attackers to execute arbitrary code via a stack-based buffer overflow in the formSetCfm function. Attackers can exploit this by sending specially crafted requests to the /goform/setcfm endpoint, potentially gaining full control of affected devices. All users of Tenda AC500 routers with firmware version 2.0.1.9(1307) are affected.
💻 Affected Systems
- Tenda AC500
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, allowing attackers to install persistent malware, pivot to internal networks, or use the device as part of a botnet.
Likely Case
Remote code execution enabling attackers to modify router settings, intercept network traffic, or launch attacks against internal systems.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering, though internal exploitation remains possible.
🎯 Exploit Status
Public exploit code is available on GitHub, making exploitation trivial for attackers with basic skills.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None available - vendor did not respond to disclosure
Restart Required: Yes
Instructions:
No official patch available. Consider replacing affected devices or implementing strict network controls.
🔧 Temporary Workarounds
Disable remote management
allDisable web management interface access from WAN/Internet
Network segmentation
allPlace affected routers in isolated network segments with strict firewall rules
🧯 If You Can't Patch
- Immediately isolate affected devices from internet access using firewall rules
- Implement strict network monitoring for unusual traffic patterns to/from router management interface
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via web interface at http://router-ip/ or using command: telnet router-ip (if enabled) and checking version infoCheck Version:
Check web interface at http://router-ip/ under System Status or Advanced SettingsVerify Fix Applied:
No fix available to verify. Monitor for firmware updates from vendor.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /goform/setcfm with long parameter values
- Multiple failed login attempts followed by successful exploitation
Network Indicators:
- Unusual outbound connections from router to unknown IPs
- Traffic patterns suggesting command and control communication
SIEM Query:
source_ip=router_ip AND (url_path="/goform/setcfm" OR (http_method="POST" AND url_contains="setcfm"))🔗 References
- https://github.com/abcdefg-png/IoT-vulnerable/blob/main/Tenda/AC500/formSetCfm.md
- https://vuldb.com/?ctiid.261143
- https://vuldb.com/?id.261143
- https://vuldb.com/?submit.313802
- https://github.com/abcdefg-png/IoT-vulnerable/blob/main/Tenda/AC500/formSetCfm.md
- https://vuldb.com/?ctiid.261143
- https://vuldb.com/?id.261143
- https://vuldb.com/?submit.313802
