CVE-2021-1490: Cisco Web Security Appliance

Medium severity, CVSS 6.1. EPSS: 0.7% chance of exploitation in the next 30 days.

A vulnerability in the web-based management interface of Cisco AsyncOS for Cisco Web Security Appliance (WSA) could allow an unauthenticated, remote attacker to conduct a cross-site scripting (XSS) attack against a user of the interface of an affected device. This vulnerability is due to improper validation of user-supplied input in the web-based management interface. An attacker could exploit this vulnerability by persuading a user to retrieve a crafted file that contains malicious payload and upload it to the affected device. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected interface or access sensitive, browser-based information.

Affected products

• Cisco Web Security Appliance: before 14.0 (fixed in 14.0)

Published 2021-05-06. Last modified 2026-06-17.