The vulnerability resides in the System Information Settings page of the D‑Link DGS‑3420 router. An attacker can supply a specially crafted System Name parameter that is reflected back into the page without proper sanitization, leading to cross‑site scripting. This flaw allows arbitrary JavaScript execution in the browser of any user who views the page, potentially enabling session hijacking, credential theft, or malicious navigation. The flaw is classified as CWE‑79 and also involves potential code injection (CWE‑94).

This issue affects D‑Link DGS‑3420 devices running firmware version 1.50.018. No other firmware releases or builds were specified in the advisory, so only this version is known to be vulnerable. The router interface is the target of the attack; the vulnerability lies in the web‑based System Information Settings component.

The CVSS base score is 6.8, indicating a moderate severity level. The EPSS score is below 1 %, meaning the likelihood of exploitation is low at the moment. The vulnerability is not listed in the CISA KEV catalog. Remote exploitation is possible; an attacker only needs to send a request containing a malicious System Name value to the router’s web interface, which is reachable over the network. Because the flaw occurs on a publicly reachable input and the payload is executed in the victim’s browser, the risk is primarily to users who log into the router remotely.