CVE-2025-6616
📋 TL;DR
This critical vulnerability in D-Link DIR-619L routers allows remote attackers to execute arbitrary code via a stack-based buffer overflow in the web management interface. Attackers can exploit this by sending specially crafted requests to the vulnerable formSetWAN_Wizard51 function. Only users of the unsupported DIR-619L firmware version 2.06B01 are affected.
💻 Affected Systems
- D-Link DIR-619L
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise leading to persistent backdoor installation, network traffic interception, lateral movement to connected devices, and botnet recruitment.
Likely Case
Remote code execution allowing attackers to modify router settings, intercept traffic, or use the device as a pivot point for further attacks.
If Mitigated
Limited impact if device is isolated behind firewalls with strict inbound filtering, though internal network compromise remains possible.
🎯 Exploit Status
Proof-of-concept exploit code is publicly available on GitHub, making exploitation trivial for attackers with basic skills.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: N/A
Vendor Advisory: N/A
Restart Required: No
Instructions:
No official patch available. D-Link has ended support for this product. Immediate replacement with supported hardware is recommended.
🔧 Temporary Workarounds
Disable WAN Management
allPrevent remote access to the router's web interface from the internet
Login to router admin panel → Advanced → Remote Management → Disable
Network Segmentation
allIsolate the router from critical internal networks
🧯 If You Can't Patch
- Immediately replace the DIR-619L with a currently supported router model
- Place the router behind a firewall that blocks all inbound traffic to port 80/443 and disable UPnP
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface: Login → Tools → System Info → Firmware VersionCheck Version:
N/A - Use web interface as described aboveVerify Fix Applied:
Since no patch exists, verification requires confirming device replacement or workaround implementation📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /goform/formSetWAN_Wizard51 with malformed curTime parameter
- Multiple failed login attempts followed by exploitation attempts
Network Indicators:
- Unusual outbound connections from router to unknown IPs
- Traffic spikes from router to command-and-control servers
SIEM Query:
source="router.logs" AND (url="/goform/formSetWAN_Wizard51" OR (event="buffer_overflow" AND process="httpd"))