CVE-2025-61577
📋 TL;DR
A stack overflow vulnerability in D-Link DIR-816A2 routers allows attackers to cause Denial of Service (DoS) by sending crafted input to the statuscheckpppoeuser parameter. This affects users of DIR-816A2 routers with firmware version 1.10CNB05. The vulnerability requires network access to the router's web interface.
💻 Affected Systems
- D-Link DIR-816A2
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete router crash requiring physical reboot, potentially disrupting all network connectivity for connected devices.
Likely Case
Router becomes unresponsive to web interface requests, requiring reboot to restore management functionality.
If Mitigated
No impact if router is behind firewall blocking external access to web interface.
🎯 Exploit Status
Exploit requires authentication to router web interface; public proof-of-concept code exists in GitHub repositories.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not available
Vendor Advisory: https://www.dlink.com/en/security-bulletin/
Restart Required: No
Instructions:
No official patch available. Check D-Link security bulletin for updates and consider workarounds or replacement.
🔧 Temporary Workarounds
Disable remote management
allPrevent external access to router web interface
Access router admin panel → Advanced → Remote Management → Disable
Change default credentials
allUse strong unique password for router admin access
Access router admin panel → Tools → Admin → Set new password
🧯 If You Can't Patch
- Replace router with supported model that receives security updates
- Place router behind firewall that blocks all external access to web interface ports
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin panel under Tools → System InfoCheck Version:
Not applicable - check via web interfaceVerify Fix Applied:
No fix available to verify; monitor D-Link security bulletins for updates📡 Detection & Monitoring
Log Indicators:
- Multiple failed authentication attempts followed by POST requests to dir_setWanWifi with long statuscheckpppoeuser parameter
- Router crash/reboot logs
Network Indicators:
- HTTP POST requests to router IP on port 80/443 with unusually long parameter values
- Sudden loss of router responsiveness
SIEM Query:
source="router.log" AND ("dir_setWanWifi" OR "statuscheckpppoeuser") AND content_length>1000