CVE-2024-7159
📋 TL;DR
This CVE describes a critical vulnerability in TOTOLINK A3600R routers where the Telnet service uses a hard-coded password in the product.ini file. Attackers can exploit this to gain unauthorized access to affected devices. This affects TOTOLINK A3600R routers running firmware version 4.1.2cu.5182_B20201102.
💻 Affected Systems
- TOTOLINK A3600R
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the router allowing attackers to intercept traffic, modify configurations, install malware, or use the device as part of a botnet.
Likely Case
Unauthorized administrative access to the router enabling network reconnaissance, traffic monitoring, and potential lateral movement to connected devices.
If Mitigated
Limited impact if Telnet is disabled and strong perimeter controls prevent external access to management interfaces.
🎯 Exploit Status
Exploit details are publicly available on GitHub, making this trivial to exploit by anyone with network access to the Telnet service.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None available - vendor did not respond to disclosure
Restart Required: No
Instructions:
No official patch available. Contact TOTOLINK support for firmware updates and monitor their website for security advisories.
🔧 Temporary Workarounds
Disable Telnet Service
allCompletely disable the Telnet service and use SSH with strong authentication instead.
Access router admin interface → Services → Telnet → Disable
Restrict Telnet Access
linuxConfigure firewall rules to restrict Telnet access to trusted management networks only.
iptables -A INPUT -p tcp --dport 23 -s [TRUSTED_IP] -j ACCEPT
iptables -A INPUT -p tcp --dport 23 -j DROP
🧯 If You Can't Patch
- Isolate affected routers in a separate VLAN with strict access controls
- Implement network segmentation to limit potential lateral movement from compromised routers
🔍 How to Verify
Check if Vulnerable:
Attempt to connect to Telnet port 23 using the hard-coded credentials disclosed in the public exploit. If access is granted, the device is vulnerable.Check Version:
Check router web interface or use: telnet [router_ip] → login with admin credentials → check firmware versionVerify Fix Applied:
Verify Telnet service is disabled or inaccessible. Test that Telnet connections fail even with known credentials.📡 Detection & Monitoring
Log Indicators:
- Failed Telnet authentication attempts followed by successful login
- Multiple Telnet connections from unusual IP addresses
- Configuration changes via Telnet session
Network Indicators:
- Telnet traffic to router management interfaces from unauthorized sources
- Unusual outbound connections from router after Telnet access
SIEM Query:
source="router_logs" AND (event="telnet_login" AND result="success") OR (port=23 AND dest_ip="[ROUTER_IP]")🔗 References
- https://github.com/abcdefg-png/IoT-vulnerable/blob/main/TOTOLINK/A3600R/product.md
- https://vuldb.com/?ctiid.272573
- https://vuldb.com/?id.272573
- https://vuldb.com/?submit.377942
- https://github.com/abcdefg-png/IoT-vulnerable/blob/main/TOTOLINK/A3600R/product.md
- https://vuldb.com/?ctiid.272573
- https://vuldb.com/?id.272573
- https://vuldb.com/?submit.377942
