CVE-2025-5905
📋 TL;DR
A critical buffer overflow vulnerability in TOTOLINK T10 routers allows remote attackers to execute arbitrary code by sending specially crafted POST requests to the setWiFiRepeaterCfg function. This affects TOTOLINK T10 routers running firmware version 4.1.8cu.5207. Attackers can exploit this without authentication to potentially take full control of affected devices.
💻 Affected Systems
- TOTOLINK T10
📦 What is this software?
T10 Firmware by Totolink
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, persistence installation, lateral movement to internal networks, and data exfiltration.
Likely Case
Device takeover for botnet recruitment, credential theft, or network traffic interception.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering and network segmentation.
🎯 Exploit Status
Public exploit details are available, making this easily weaponizable by 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. 3. Access router admin interface. 4. Navigate to firmware upgrade section. 5. Upload and apply new firmware. 6. Reboot router.
🔧 Temporary Workarounds
Network Access Control
linuxBlock external access to router administration interface
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP
Disable Remote Management
allTurn off remote administration features in router settings
🧯 If You Can't Patch
- Isolate affected routers in separate VLAN with strict firewall rules
- Implement network monitoring for suspicious POST requests to /cgi-bin/cstecgi.cgi
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface or via SSH: cat /proc/versionCheck Version:
ssh admin@router-ip 'cat /proc/version' or check web interfaceVerify Fix Applied:
Verify firmware version has been updated beyond 4.1.8cu.5207📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /cgi-bin/cstecgi.cgi
- Multiple failed buffer overflow attempts in system logs
Network Indicators:
- HTTP POST requests with oversized Password parameter to router IP
- Traffic patterns indicating exploit attempts
SIEM Query:
source="router.log" AND "POST /cgi-bin/cstecgi.cgi" AND "setWiFiRepeaterCfg"🔗 References
- https://candle-throne-f75.notion.site/TOTOLINK-T10-setWiFiRepeaterCfg-20bdf0aa118580bd8cd0da62d4d2e47f?pvs=73
- https://vuldb.com/?ctiid.311678
- https://vuldb.com/?id.311678
- https://vuldb.com/?submit.592265
- https://www.totolink.net/
- https://candle-throne-f75.notion.site/TOTOLINK-T10-setWiFiRepeaterCfg-20bdf0aa118580bd8cd0da62d4d2e47f?pvs=73
