CVE-2026-3801
📋 TL;DR
A stack-based buffer overflow vulnerability in Tenda i3 routers allows remote attackers to execute arbitrary code by manipulating ping1/ping2 parameters in the formSetAutoPing function. This affects Tenda i3 routers running firmware version 1.0.0.6(2204). Attackers can exploit this remotely without authentication to potentially take full control of affected devices.
💻 Affected Systems
- Tenda i3 router
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, persistence installation, network pivoting, and data exfiltration.
Likely Case
Device takeover enabling network traffic interception, DNS hijacking, or botnet recruitment.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering and network segmentation.
🎯 Exploit Status
Public exploit code available on GitHub. Remote exploitation requires no authentication.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not found
Restart Required: Yes
Instructions:
1. Check Tenda website for firmware updates. 2. Download latest firmware. 3. Access router admin panel. 4. Navigate to firmware upgrade section. 5. Upload and apply new firmware. 6. Reboot router.
🔧 Temporary Workarounds
Disable remote management
allPrevent external access to router management interface
Access router admin panel → System → Remote Management → Disable
Network segmentation
allIsolate router management interface to trusted network segment
🧯 If You Can't Patch
- Replace affected devices with patched or alternative models
- Implement strict firewall rules blocking all inbound traffic to router management ports (typically 80, 443, 8080)
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router admin panel: System → Firmware Upgrade → Current Version should show 1.0.0.6(2204)Check Version:
curl -s http://router-ip/goform/getStatus | grep versionVerify Fix Applied:
Verify firmware version is updated to a version later than 1.0.0.6(2204)📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /goform/setAutoPing with long ping1/ping2 parameters
- Multiple failed exploitation attempts
Network Indicators:
- Traffic to router management ports from unexpected sources
- POST requests with abnormally long parameter values
SIEM Query:
source="router_logs" AND uri="/goform/setAutoPing" AND (param_length(ping1)>100 OR param_length(ping2)>100)🔗 References
- https://github.com/Svigo-o/Tenda_vul/tree/main/tenda-i3-setautoping-ping1-buffer-overflow
- https://github.com/Svigo-o/Tenda_vul/tree/main/tenda-i3-setautoping-ping2-buffer-overflow
- https://vuldb.com/?ctiid.349768
- https://vuldb.com/?id.349768
- https://vuldb.com/?submit.768980
- https://vuldb.com/?submit.768982
- https://www.tenda.com.cn/
