CVE-2020-19318
📋 TL;DR
This CVE describes a buffer overflow vulnerability in D-Link DIR-605L routers that allows authenticated attackers to execute arbitrary code by sending crafted data to the webserver service. The vulnerability affects hardware version AX with firmware version 1.17beta and below. Successful exploitation could lead to complete compromise of the affected router.
💻 Affected Systems
- D-Link DIR-605L
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete router compromise allowing attacker to intercept all network traffic, install persistent backdoors, pivot to internal networks, and potentially brick the device.
Likely Case
Router takeover enabling traffic monitoring, credential theft, and use as a foothold for further attacks on connected devices.
If Mitigated
Limited impact if router is behind firewall with restricted web interface access and strong authentication.
🎯 Exploit Status
Exploit requires authentication to the router web interface. Public proof-of-concept code is available on GitHub.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Firmware version after 1.17beta
Vendor Advisory: https://support.dlink.com/ProductInfo.aspx?m=DIR-605L
Restart Required: Yes
Instructions:
1. Download latest firmware from D-Link support site. 2. Log into router web interface. 3. Navigate to Tools > Firmware. 4. Upload and install new firmware. 5. Wait for router to reboot.
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to router web interface
Log into router > Tools > Admin > Disable 'Enable Remote Management'
Change Default Credentials
allUse strong unique credentials to reduce authentication risk
Log into router > Tools > Admin > Change admin password
🧯 If You Can't Patch
- Isolate router on separate VLAN with strict firewall rules
- Implement network monitoring for suspicious traffic to router web interface
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in web interface: Status > Device Info > Firmware VersionCheck Version:
curl -s http://router-ip/status_deviceinfo.htm | grep FirmwareVerify Fix Applied:
Verify firmware version is above 1.17beta after update📡 Detection & Monitoring
Log Indicators:
- Multiple failed login attempts followed by successful login and unusual POST requests to webserver
Network Indicators:
- Unusual traffic patterns to router web interface, especially large crafted HTTP requests
SIEM Query:
source="router-logs" AND (event="authentication_success" OR url="*.cgi") AND bytes>10000