CVE-2026-0641
📋 TL;DR
This CVE describes a command injection vulnerability in TOTOLINK WA300 routers that allows remote attackers to execute arbitrary commands on affected devices. The vulnerability exists in the cstecgi.cgi file's sub_401510 function via manipulation of the UPLOAD_FILENAME argument. Organizations using TOTOLINK WA300 routers with the vulnerable firmware version are affected.
💻 Affected Systems
- TOTOLINK WA300
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the router allowing attackers to establish persistence, pivot to internal networks, intercept traffic, or use the device for botnet activities.
Likely Case
Remote code execution leading to device compromise, credential theft, network reconnaissance, or denial of service.
If Mitigated
Limited impact if network segmentation prevents lateral movement and the device is not internet-facing.
🎯 Exploit Status
Public proof-of-concept exists, making exploitation straightforward for attackers with basic skills.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: No
Instructions:
Check TOTOLINK vendor website for firmware updates. If available, download and apply the latest firmware through the router's web interface.
🔧 Temporary Workarounds
Network Segmentation
allIsolate affected routers from critical network segments and restrict access to management interfaces.
Access Control Lists
allImplement firewall rules to restrict access to the vulnerable CGI endpoint (typically port 80/443).
🧯 If You Can't Patch
- Replace affected devices with supported models from vendors providing security updates.
- Implement strict network monitoring and intrusion detection for suspicious activity targeting the routers.
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via web interface (typically under System Status or About page).Check Version:
Not applicable - check via web interface or consult device documentation.Verify Fix Applied:
Verify firmware version has been updated to a version newer than 5.2cu.7112_B20190227.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to cstecgi.cgi with UPLOAD_FILENAME parameter containing shell metacharacters
- Unexpected command execution in system logs
Network Indicators:
- Suspicious traffic to router management interface from unexpected sources
- Outbound connections from router to unknown destinations
SIEM Query:
source="router_logs" AND (uri="*cstecgi.cgi*" AND (param="*UPLOAD_FILENAME*" AND value="*;*" OR value="*|*" OR value="*`*"))