CVE-2024-41616
📋 TL;DR
D-Link DIR-300 REVA routers running firmware v1.06B05_WW contain hardcoded credentials in their Telnet service, allowing attackers to gain administrative access. This affects all users of these specific router models with the vulnerable firmware version. Attackers can completely compromise the router and potentially pivot to internal networks.
💻 Affected Systems
- D-Link DIR-300 REVA
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete router takeover leading to network compromise, traffic interception, credential theft, and lateral movement to connected devices.
Likely Case
Router compromise enabling network monitoring, DNS hijacking, and access to connected IoT devices.
If Mitigated
Limited impact if Telnet is disabled and strong perimeter controls prevent external access.
🎯 Exploit Status
Exploitation requires only Telnet access and knowledge of hardcoded credentials. Public proof-of-concept exists in GitHub repositories.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: None available
Vendor Advisory: Not available
Restart Required: No
Instructions:
No official patch exists. Consider replacing affected hardware with supported models.
🔧 Temporary Workarounds
Disable Telnet Service
linuxCompletely disable Telnet access to prevent credential exploitation
telnetd stop
killall telnetd
chmod -x /usr/sbin/telnetd
Network Access Control
linuxBlock Telnet port 23 at firewall/network perimeter
iptables -A INPUT -p tcp --dport 23 -j DROP
🧯 If You Can't Patch
- Replace affected hardware with supported models
- Isolate vulnerable routers in separate network segments with strict firewall rules
🔍 How to Verify
Check if Vulnerable:
Check firmware version in web interface or via command: cat /etc/versionCheck Version:
cat /etc/versionVerify Fix Applied:
Attempt Telnet connection to port 23 - should be unreachable or require authentication📡 Detection & Monitoring
Log Indicators:
- Failed/successful Telnet authentication attempts
- Telnet service start/stop events
Network Indicators:
- Telnet connections to port 23 from external IPs
- Multiple failed login attempts followed by success
SIEM Query:
source="router.log" AND ("telnet" OR "port 23") AND ("login" OR "authentication")