CVE-2026-3044
📋 TL;DR
A stack-based buffer overflow vulnerability in Tenda AC8 routers allows remote attackers to execute arbitrary code by manipulating the boundary argument in the webCgiGetUploadFile function. This affects Tenda AC8 routers running firmware version 16.03.34.06. 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
Remote code execution leading to complete device compromise, lateral movement to internal networks, persistent backdoor installation, and data exfiltration.
Likely Case
Remote code execution allowing attackers to modify router settings, intercept network traffic, or use the device as part of a botnet.
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: https://www.tenda.com.cn/
Restart Required: Yes
Instructions:
1. Check Tenda website for firmware updates. 2. Download latest firmware. 3. Access router admin interface. 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 web interface
Network Segmentation
allIsolate router management interface from untrusted networks
🧯 If You Can't Patch
- Replace affected devices with patched or alternative models
- Implement strict network access controls to limit exposure
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via admin interface. If version is 16.03.34.06, device is vulnerable.Check Version:
Check via router web interface or SSH if enabled: cat /proc/version or similar firmware version filesVerify Fix Applied:
Verify firmware version has been updated to a version later than 16.03.34.06.📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP POST requests to /cgi-bin/UploadCfg
- Multiple failed upload attempts
- Abnormal process creation
Network Indicators:
- Unexpected outbound connections from router
- Traffic patterns suggesting command and control
SIEM Query:
source="router_logs" AND (uri="/cgi-bin/UploadCfg" OR process="httpd") AND (method="POST" AND size>normal)