CVE-2025-60331
📋 TL;DR
A buffer overflow vulnerability exists in the FillMacCloneMac parameter of the /EXCU_SHELL endpoint on D-Link DIR-823G A1 routers running firmware v1.0.2B05. Attackers can exploit this by sending crafted inputs to cause a Denial of Service (DoS), potentially crashing the device. This affects all users of the specified router model and firmware version.
💻 Affected Systems
- D-Link DIR-823G A1
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device crash requiring physical reboot, potential remote code execution if the overflow can be controlled precisely (though not indicated in description).
Likely Case
Denial of Service causing router reboot and network disruption for connected devices.
If Mitigated
Limited impact if device is behind firewall with restricted access to management interface.
🎯 Exploit Status
Public PoC exists on GitHub, making exploitation straightforward for attackers with basic skills. The description suggests unauthenticated access to the vulnerable endpoint.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://www.dlink.com/en/security-bulletin/
Restart Required: Yes
Instructions:
1. Check D-Link security bulletin for firmware updates. 2. Download updated firmware from D-Link support site. 3. Log into router admin interface. 4. Navigate to firmware update section. 5. Upload and apply the new firmware. 6. Wait for router to reboot.
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to router management interface
Log into router admin → System → Remote Management → Disable
Restrict Management Access
allLimit management interface access to specific IP addresses
Log into router admin → Firewall → Access Control → Add rules to restrict admin access
🧯 If You Can't Patch
- Replace affected router with a different model that receives security updates
- Isolate router in separate network segment with strict firewall rules blocking access to management ports
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface under System → FirmwareCheck Version:
curl -s http://router-ip/status.html | grep FirmwareVerify Fix Applied:
Verify firmware version has been updated to a version later than v1.0.2B05📡 Detection & Monitoring
Log Indicators:
- Multiple requests to /EXCU_SHELL endpoint
- Router crash/reboot events in system logs
- Unusual POST requests with large FillMacCloneMac parameter
Network Indicators:
- HTTP POST requests to router IP on port 80/443 targeting /EXCU_SHELL
- Sudden loss of connectivity to router management interface
SIEM Query:
source="router_logs" AND (uri="/EXCU_SHELL" OR message="reboot" OR message="crash")