CVE-2023-50207
📋 TL;DR
This vulnerability allows attackers on the same network to execute arbitrary commands as root on D-Link G416 routers without authentication. The flaw exists in the HTTP service on port 80 where user input isn't properly validated before being used in system calls. All users of affected D-Link G416 routers are at risk.
💻 Affected Systems
- D-Link G416 Wireless AC1600 Dual Band Gigabit Router
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the router with root access, allowing attackers to intercept/modify all network traffic, install persistent malware, pivot to internal networks, or brick the device.
Likely Case
Attackers gaining full control of the router to monitor network traffic, redirect DNS, or use as a foothold for further attacks on the internal network.
If Mitigated
Limited impact if router is isolated from critical systems and network segmentation prevents lateral movement.
🎯 Exploit Status
Exploit details are publicly available through ZDI advisory. Attack requires network adjacency but no authentication.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Firmware version 1.03
Vendor Advisory: https://supportannouncement.us.dlink.com/announcement/publication.aspx?name=SAP10367
Restart Required: Yes
Instructions:
1. Download firmware version 1.03 from D-Link support site. 2. Log into router admin interface. 3. Navigate to Maintenance > Firmware Update. 4. Upload and install the new firmware. 5. Wait for router to reboot automatically.
🔧 Temporary Workarounds
Disable HTTP Management Interface
allDisable the vulnerable HTTP service on port 80 and use HTTPS management only
Login to router admin > Management > Access Control > Disable HTTP
Restrict Management Access
allLimit management interface access to specific trusted IP addresses only
Login to router admin > Management > Access Control > Add allowed IP addresses
🧯 If You Can't Patch
- Isolate the router on a separate VLAN with strict firewall rules limiting inbound/outbound traffic
- Implement network monitoring for unusual HTTP requests to router management interface
🔍 How to Verify
Check if Vulnerable:
Check current firmware version in router admin interface under Status > Device Info. If version is below 1.03, device is vulnerable.Check Version:
curl -s http://router-ip/status.html | grep -i firmwareVerify Fix Applied:
After updating, verify firmware version shows 1.03 in Status > Device Info. Test that HTTP service still responds but exploit attempts fail.📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP POST requests to router management interface with command injection patterns
- Multiple failed login attempts followed by successful command execution
Network Indicators:
- HTTP requests containing shell metacharacters (;, |, &, $) sent to router port 80
- Unexpected outbound connections from router to external IPs
SIEM Query:
source="router-logs" AND (http_method="POST" AND (uri="*flupl*" OR http_user_agent="*curl*" OR http_user_agent="*wget*"))