CVE-2026-1156
📋 TL;DR
A buffer overflow vulnerability in Totolink LR350 routers allows remote attackers to execute arbitrary code by manipulating the ssid parameter in the setWiFiBasicCfg function. This affects Totolink LR350 routers running firmware version 9.3.5u.6369_B20220309. Attackers can exploit this without authentication to potentially take full control of affected devices.
💻 Affected Systems
- Totolink LR350
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, creation of persistent backdoors, network pivoting, and data exfiltration.
Likely Case
Device takeover 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 ingress filtering and network segmentation.
🎯 Exploit Status
Public exploit details are available in the disclosed references. The vulnerability requires sending specially crafted HTTP requests to the vulnerable endpoint.
🛠️ 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 LR350. 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
linuxRestrict access to router management interface using firewall rules.
iptables -A INPUT -p tcp --dport 80 -s TRUSTED_IP -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -s TRUSTED_IP -j ACCEPT
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 network segmentation
- Implement network monitoring and intrusion detection for exploit attempts
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via admin interface or using curl: curl -k http://ROUTER_IP/cgi-bin/cstecgi.cgiCheck Version:
curl -k http://ROUTER_IP/cgi-bin/cstecgi.cgi | grep -i versionVerify Fix Applied:
Verify firmware version has been updated to a version later than 9.3.5u.6369_B20220309📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP POST requests to /cgi-bin/cstecgi.cgi with setWiFiBasicCfg function
- Large ssid parameter values in HTTP requests
- Router crash or reboot logs
Network Indicators:
- HTTP requests with abnormally long ssid parameters
- Multiple failed exploit attempts from single source
SIEM Query:
source="router_logs" AND (uri="/cgi-bin/cstecgi.cgi" AND method="POST" AND params CONTAINS "setWiFiBasicCfg")