CVE-2021-1271: Cisco Web Security Virtual Appliance

Medium severity, CVSS 4.8. EPSS: 0.8% 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 authenticated, remote attacker to conduct a stored cross-site scripting (XSS) attack against a user of the interface of an affected device. The vulnerability exists because the web-based management interface does not properly validate user-supplied input. An attacker could exploit this vulnerability by inserting malicious data into a specific data field in an affected interface. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected interface.

Affected products

• Cisco Web Security Virtual Appliance: before 12.5.1 (fixed in 12.5.1)

Published 2021-01-20. Last modified 2026-06-17.