CVE-2021-1374: Cisco IOS XE

Medium severity, CVSS 4.8. EPSS: 0.6% chance of exploitation in the next 30 days.

A vulnerability in the web-based management interface of Cisco IOS XE Wireless Controller software for the Catalyst 9000 Family of switches could allow an authenticated, remote attacker to conduct a cross-site scripting (XSS) attack against another user of the web-based management interface of an affected device. The vulnerability is due to insufficient validation of user-supplied input by the web-based management interface of an affected device. An attacker could exploit this vulnerability by authenticating to the device as a high-privileged user, adding certain configurations with malicious code in one of its fields, and persuading another user to click on it. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected interface or to access sensitive, browser-based information.

Affected products

• Cisco IOS XE: version 16.6.1 only; version 16.6.2 only; version 16.6.3 only; version 16.6.4 only; version 16.6.4a only; version 16.6.4s only; …

Published 2021-03-24. Last modified 2026-06-17.