CVE-2024-7185
📋 TL;DR
This critical vulnerability in TOTOLINK A3600R routers allows remote attackers to execute arbitrary code via a buffer overflow in the setWebWlanIdx function. Attackers can exploit this without authentication to potentially take full control of affected devices. All users of TOTOLINK A3600R routers running vulnerable firmware versions are affected.
💻 Affected Systems
- TOTOLINK A3600R
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, persistent backdoor installation, network pivoting, and data exfiltration.
Likely Case
Remote code execution allowing attackers to modify router settings, intercept traffic, or use the device as part of a botnet.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering and network segmentation.
🎯 Exploit Status
Exploit details are publicly available on GitHub, making weaponization likely. The vulnerability requires no authentication and has straightforward exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None available
Restart Required: Yes
Instructions:
No official patch is available. The vendor did not respond to disclosure attempts. Consider replacing affected devices or implementing workarounds.
🔧 Temporary Workarounds
Network Segmentation and Access Control
allIsolate affected routers in separate network segments and restrict access to management interfaces.
Firewall Rules to Block CGI Access
linuxBlock external access to /cgi-bin/cstecgi.cgi on affected routers.
iptables -A INPUT -p tcp --dport 80 -m string --string "/cgi-bin/cstecgi.cgi" --algo bm -j DROP
iptables -A INPUT -p tcp --dport 443 -m string --string "/cgi-bin/cstecgi.cgi" --algo bm -j DROP
🧯 If You Can't Patch
- Replace affected TOTOLINK A3600R routers with devices from vendors that provide security updates
- Implement strict network segmentation to isolate vulnerable routers from critical network segments
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via web interface at 192.168.1.1 or using command: curl -s http://192.168.1.1/cgi-bin/cstecgi.cgi | grep -i versionCheck Version:
curl -s http://[router-ip]/cgi-bin/cstecgi.cgi | grep -i 'version\|firmware'Verify Fix Applied:
No official fix exists to verify. Monitor for firmware updates from TOTOLINK and verify version is newer than 4.1.2cu.5182_B20201102.📡 Detection & Monitoring
Log Indicators:
- Multiple requests to /cgi-bin/cstecgi.cgi with webWlanIdx parameter
- Unusual process execution or memory errors in router logs
- Configuration changes not initiated by administrators
Network Indicators:
- Unusual outbound connections from router to unknown IPs
- Traffic patterns suggesting command and control communication
- Exploit attempts targeting /cgi-bin/cstecgi.cgi with long webWlanIdx values
SIEM Query:
source="router_logs" AND (uri="/cgi-bin/cstecgi.cgi" AND (webWlanIdx.length>100 OR status=500))🔗 References
- https://github.com/abcdefg-png/IoT-vulnerable/blob/main/TOTOLINK/A3600R/setWebWlanIdx.md
- https://vuldb.com/?ctiid.272606
- https://vuldb.com/?id.272606
- https://vuldb.com/?submit.378054
- https://github.com/abcdefg-png/IoT-vulnerable/blob/main/TOTOLINK/A3600R/setWebWlanIdx.md
- https://vuldb.com/?ctiid.272606
- https://vuldb.com/?id.272606
- https://vuldb.com/?submit.378054
