A flaw in the TEW‑821DAP firmware update diagnostic tool allows attackers to inject arbitrary operating‑system commands, resulting in remote code execution. The vulnerability exists in the tools_diagnostic function of the /tmp/diagnostic component for firmware versions up to 1.12B01. Exploitation can be achieved remotely, and an exploit has already been published and is available for use. This means an attacker could potentially gain full control of the device’s operating system, compromising confidentiality, integrity, and availability of the device.

The Trendnet TEW‑821DAP wireless access point is affected. Any unit running firmware version 1.12B01 or earlier is vulnerable. Versions higher than 1.12B01 are not known to be impacted, and the product has been out of support for about eight years, with no current releases available from the vendor.

The CVSS score of 5.3 indicates a moderate severity vulnerability, and the EPSS score is not provided. The issue is not listed in CISA KEV. Because the component is exposed remotely, the likely attack vector is through publicly reachable links or management interfaces. Remote attackers can invoke the vulnerable API to run arbitrary commands on the device. The vulnerability is exploitable from any host that can reach the diagnostic endpoint, making it a high‑risk threat if the device is connected to untrusted networks.