CVE-2026-3378
📋 TL;DR
CVE-2026-3378 is a remote buffer overflow vulnerability in Tenda F453 routers affecting the qossetting function. Attackers can exploit this flaw remotely without authentication to execute arbitrary code or cause denial of service. This affects Tenda F453 router users running vulnerable firmware.
💻 Affected Systems
- Tenda F453
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete router compromise, network infiltration, and persistent backdoor installation.
Likely Case
Router crash/reboot causing denial of service, potentially allowing credential theft or network disruption.
If Mitigated
Limited impact if network segmentation isolates routers and strict access controls prevent external exploitation.
🎯 Exploit Status
Public exploit code exists in GitHub repositories. Attack requires sending specially crafted HTTP requests to the vulnerable endpoint.
🛠️ 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. Upload and apply firmware update. 5. Reboot router.
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to router web interface
Access router admin panel → Security → Disable Remote Management
Network Segmentation
allIsolate router management interface from untrusted networks
Configure firewall rules to restrict access to router IP on ports 80/443
🧯 If You Can't Patch
- Replace vulnerable routers with updated models or different vendors
- Implement strict network access controls and monitor for exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface. If version is 1.0.0.3, device is vulnerable.Check Version:
Access router web interface at http://[router-ip] and check System Status or About pageVerify Fix Applied:
Verify firmware version has changed from 1.0.0.3 to a newer version after update.📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP POST requests to /goform/qossetting
- Router crash/reboot logs
- Buffer overflow error messages
Network Indicators:
- HTTP traffic to router IP with abnormal qos parameter values
- Multiple connection attempts to router management interface
SIEM Query:
source="router_logs" AND (url="/goform/qossetting" OR message="buffer overflow" OR message="segmentation fault")