CVE-2021-21799: Advantech R-Seenet

Medium severity, CVSS 6.1. EPSS: 12.3% chance of exploitation in the next 30 days.

Cross-site scripting vulnerabilities exist in the telnet_form.php script functionality of Advantech R-SeeNet v 2.4.12 (20.10.2020). If a user visits a specially crafted URL, it can lead to arbitrary JavaScript code execution in the context of the targeted user’s browser. An attacker can provide a crafted URL to trigger this vulnerability.

Affected products

Published 2021-07-16. Last modified 2026-06-17.