CVE-2024-11066
📋 TL;DR
This CVE describes an OS command injection vulnerability in D-Link DSL6740C modems that allows authenticated attackers with administrator privileges to execute arbitrary system commands through a specific web interface. This affects all users of D-Link DSL6740C modems, particularly those with devices exposed to the internet. The vulnerability enables complete system compromise of affected devices.
💻 Affected Systems
- D-Link DSL6740C
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device takeover leading to persistent backdoor installation, network traffic interception, credential theft, and use as a pivot point into internal networks.
Likely Case
Attackers with admin credentials can execute arbitrary commands to modify device configuration, install malware, or disrupt network connectivity.
If Mitigated
With proper network segmentation and access controls, impact is limited to the modem device itself without lateral movement.
🎯 Exploit Status
Exploitation requires admin credentials but is straightforward once authenticated. Public technical details are available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: None
Vendor Advisory: https://www.twcert.org.tw/en/cp-139-8232-5d94e-2.html
Restart Required: No
Instructions:
No official patch available. D-Link has declared this device End-of-Life and will not provide fixes.
🔧 Temporary Workarounds
Disable remote administration
allDisable remote management/administration features to prevent external access to the vulnerable interface.
Access modem web interface > Advanced > Remote Management > Disable
Change default credentials
allChange default admin passwords to strong, unique credentials to prevent credential-based attacks.
Access modem web interface > Management > Password > Set strong password
🧯 If You Can't Patch
- Replace the modem with a supported, patched model from any vendor
- Implement network segmentation to isolate the modem from critical internal resources
🔍 How to Verify
Check if Vulnerable:
Check if you have a D-Link DSL6740C modem by accessing the web interface at 192.168.1.1 and checking the model number on the status page.Check Version:
Access modem web interface > Status > Device Information to see firmware versionVerify Fix Applied:
Since no patch exists, verification involves confirming the modem has been replaced or isolated.📡 Detection & Monitoring
Log Indicators:
- Unusual command execution in system logs
- Multiple failed login attempts followed by successful admin login
- Unexpected configuration changes
Network Indicators:
- Unusual outbound connections from modem
- Traffic to unexpected destinations
- Port scanning originating from modem
SIEM Query:
source="modem" AND (event="command_execution" OR event="config_change")