CVE-2026-1544
📋 TL;DR
This CVE describes an OS command injection vulnerability in D-Link DIR-823X routers via the lan_gateway parameter in the /goform/set_mode endpoint. Attackers can execute arbitrary commands remotely without authentication. Only affects products no longer supported by the vendor.
💻 Affected Systems
- D-Link DIR-823X
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full device compromise allowing attacker to install persistent backdoors, pivot to internal networks, or use device in botnets.
Likely Case
Device takeover for botnet participation, credential theft, or network reconnaissance.
If Mitigated
Limited impact if device is isolated behind firewalls with strict network segmentation.
🎯 Exploit Status
Exploit code is publicly available on GitHub and requires minimal technical skill to execute.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: N/A
Vendor Advisory: https://www.dlink.com/
Restart Required: No
Instructions:
No official patch available as product is end-of-life. Replace with supported hardware.
🔧 Temporary Workarounds
Network Isolation
allPlace affected devices in isolated VLAN with strict firewall rules blocking all inbound traffic.
Access Control
allBlock access to /goform/set_mode endpoint at network perimeter or web application firewall.
🧯 If You Can't Patch
- Immediately replace affected devices with supported hardware
- Implement strict network segmentation and firewall rules to isolate vulnerable devices
🔍 How to Verify
Check if Vulnerable:
Check device firmware version via web interface or SSH. If version is 250416 and model is DIR-823X, device is vulnerable.Check Version:
Check web interface at http://[router-ip]/ or via SSH: cat /etc/versionVerify Fix Applied:
No fix available to verify. Only complete replacement resolves vulnerability.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /goform/set_mode with shell metacharacters in parameters
- Unexpected command execution in system logs
Network Indicators:
- Unusual outbound connections from router
- Traffic to known C2 servers
- Port scanning from router IP
SIEM Query:
source="router.logs" AND uri="/goform/set_mode" AND (lan_gateway="*;*" OR lan_gateway="*|*" OR lan_gateway="*`*")