The Edimax BR-6675nD router runs firmware 1.12 and contains a flaw in its web interface. The formUSBStorage endpoint accepts a sub_dir parameter via POST request, and the value of this parameter is not properly sanitized. An attacker can inject arbitrary shell commands by manipulating sub_dir, which the router executes with system privileges. The result is command execution on the device, potentially granting full control to the attacker. This is a classic command injection weakness (CWE-77 and CWE-74).

Affected devices are Edimax BR-6675nD routers with firmware 1.12. No other firmware versions are listed as vulnerable, so users should verify that their product matches this version. The issue was discovered in the POST request handler and is documented by various community sources.

The vulnerability carries a CVSS score of 5.3, indicating moderate risk. No EPSS score is available, however the exploit has been published and is known to be usable remotely. The vendor has replied but did not provide a fix, and the flaw is not included in the KEV catalog. Attackers can reach the device over the network, submit a crafted POST request to /goform/formUSBStorage, and successfully inject commands.