CVE-2025-55599
📋 TL;DR
A buffer overflow vulnerability in D-Link DIR-619L routers allows attackers to execute arbitrary code by sending specially crafted input to the formWlanSetup function. This affects users running firmware version 2.06B01 who have WDS (Wireless Distribution System) enabled. Successful exploitation could lead to complete device compromise.
💻 Affected Systems
- D-Link DIR-619L
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to full router compromise, credential theft, network traffic interception, and lateral movement into connected devices.
Likely Case
Router crash/reboot causing temporary network disruption, or limited code execution allowing attacker persistence on the device.
If Mitigated
Denial of service if exploit fails or is detected, with no persistent access.
🎯 Exploit Status
Exploit requires authentication to access the vulnerable web interface endpoint. Public PoC available in GitHub repository.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None available
Restart Required: Yes
Instructions:
1. Check D-Link support site for firmware updates
2. Download latest firmware for DIR-619L
3. Access router web interface
4. Navigate to Tools > Firmware
5. Upload and apply new firmware
6. Wait for router to reboot
🔧 Temporary Workarounds
Disable WDS Feature
allTurn off Wireless Distribution System functionality to remove attack vector
Access router web interface > Wireless > WDS > Disable
Restrict Web Interface Access
allLimit administrative interface access to trusted IP addresses only
Access router web interface > Advanced > Firewall > Enable Access Control
🧯 If You Can't Patch
- Isolate vulnerable router in separate VLAN with strict firewall rules
- Replace with supported hardware if vendor no longer provides security updates
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router web interface: Status > Device Info > Firmware VersionCheck Version:
curl -s http://router-ip/status_deviceinfo.htm | grep 'Firmware Version'Verify Fix Applied:
Verify firmware version is newer than 2.06B01 and WDS is disabled📡 Detection & Monitoring
Log Indicators:
- Multiple failed login attempts followed by POST requests to /goform/formWlanSetup
- Unusual POST data length in f_wds_wepKey parameter
Network Indicators:
- HTTP POST requests to /goform/formWlanSetup with oversized f_wds_wepKey parameter
- Traffic from unexpected sources to router web interface
SIEM Query:
source="router.log" AND (uri_path="/goform/formWlanSetup" AND http_method="POST" AND content_length>100)