CVE-2023-41011
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary commands on China Mobile HG6543C4 home gateways via the shortcut_telnet.cg component. Attackers can gain full control of affected devices without authentication. All users of the vulnerable gateway version are affected.
💻 Affected Systems
- China Mobile Intelligent Home Gateway HG6543C4
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device takeover allowing attackers to intercept all network traffic, install persistent malware, pivot to internal networks, and use the device as part of botnets.
Likely Case
Attackers gain shell access to modify device settings, intercept credentials, and use the gateway as a foothold for further attacks on the internal network.
If Mitigated
With proper network segmentation and access controls, impact is limited to the gateway device itself without lateral movement.
🎯 Exploit Status
Public GitHub repository contains exploit details and likely working code. Attack requires network access to the gateway's web interface.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not found
Restart Required: No
Instructions:
No official patch available. Contact China Mobile support for firmware updates and check their website for security advisories.
🔧 Temporary Workarounds
Disable vulnerable component via firewall
linuxBlock access to the shortcut_telnet.cg endpoint using firewall rules
iptables -A INPUT -p tcp --dport 80 -m string --string "shortcut_telnet.cg" --algo bm -j DROP
iptables -A INPUT -p tcp --dport 443 -m string --string "shortcut_telnet.cg" --algo bm -j DROP
Restrict gateway management interface access
linuxLimit which IP addresses can access the gateway's web management interface
iptables -A INPUT -p tcp --dport 80 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP
🧯 If You Can't Patch
- Replace vulnerable gateway with a different model from a vendor with better security track record
- Place gateway behind a separate firewall that blocks all inbound WAN access to management interfaces
🔍 How to Verify
Check if Vulnerable:
Check if http://[gateway-ip]/shortcut_telnet.cg exists and responds. Test with curl: curl -v http://[gateway-ip]/shortcut_telnet.cgCheck Version:
Check gateway web interface at http://[gateway-ip] for firmware version information, or login via SSH/Telnet and check system infoVerify Fix Applied:
Verify the shortcut_telnet.cg endpoint no longer exists or returns access denied. Test with same curl command.📡 Detection & Monitoring
Log Indicators:
- Unusual access to shortcut_telnet.cg in web server logs
- Unexpected telnet/SSH connections originating from gateway
- Suspicious command execution in system logs
Network Indicators:
- HTTP requests to /shortcut_telnet.cg with command parameters
- Outbound connections from gateway to suspicious IPs
- Unusual traffic patterns from gateway
SIEM Query:
source="gateway-logs" AND (url="*shortcut_telnet.cg*" OR command="*telnet*" OR command="*bash*" OR command="*sh*")