CVE-2025-6137
📋 TL;DR
A critical buffer overflow vulnerability in TOTOLINK T10 routers allows remote attackers to execute arbitrary code by sending specially crafted HTTP POST requests to the setWiFiScheduleCfg function. This affects all users running TOTOLINK T10 firmware version 4.1.8cu.5207, potentially giving attackers full control of affected devices.
💻 Affected Systems
- TOTOLINK T10 router
📦 What is this software?
T10 Firmware by Totolink
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, creation of persistent backdoors, lateral movement to internal networks, and botnet recruitment.
Likely Case
Remote code execution allowing attackers to modify device configuration, intercept network traffic, or use the device as a pivot point for further attacks.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering, though internal exploitation remains possible.
🎯 Exploit Status
Public exploit details are available, and the vulnerability requires no authentication, making exploitation straightforward for attackers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://www.totolink.net/
Restart Required: Yes
Instructions:
1. Check TOTOLINK website for firmware updates. 2. Download latest firmware for T10 model. 3. Log into router admin interface. 4. Navigate to firmware upgrade section. 5. Upload and apply new firmware. 6. Reboot router.
🔧 Temporary Workarounds
Network Segmentation and Access Control
allRestrict access to router management interface using firewall rules and network segmentation.
Disable Remote Management
allTurn off remote administration features to prevent external exploitation.
🧯 If You Can't Patch
- Isolate affected routers in separate VLANs with strict firewall rules preventing access to management interfaces
- Implement network monitoring for suspicious HTTP POST requests to /cgi-bin/cstecgi.cgi with setWiFiScheduleCfg parameter
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via web interface or SSH if enabled. Look for version 4.1.8cu.5207.Check Version:
curl -s http://router-ip/ | grep -i firmware || ssh admin@router-ip 'cat /etc/version'Verify Fix Applied:
Verify firmware version has been updated to a version newer than 4.1.8cu.5207.📡 Detection & Monitoring
Log Indicators:
- HTTP POST requests to /cgi-bin/cstecgi.cgi with setWiFiScheduleCfg parameter containing unusually long desc values
- Router reboot events or configuration changes without authorized activity
Network Indicators:
- Unusual outbound connections from router to unknown IPs
- HTTP requests with buffer overflow patterns in payloads
SIEM Query:
source="router_logs" AND uri="/cgi-bin/cstecgi.cgi" AND method="POST" AND params CONTAINS "setWiFiScheduleCfg"