A vulnerability in the web-based management interface of Cisco Web Security Appliance (WSA) could allow an unauthenticated, remote attacker to conduct cross-site scripting (XSS) attacks against a user of the 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 persuading a user of the interface to click a crafted link. A successful exploit could allow the attacker to execute arbitrary script or HTML code in the context of the interface, which could allow the attacker to gain access to sensitive, browser-based information.
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20191106-wsa-xss