Description
Cross-site Scripting (XSS) refers to client-side code injection attack wherein an attacker can execute malicious scripts into a legitimate website or web application. XSS occurs when a web application makes use of unvalidated or unencoded user input within the output it generates.
Some ASP.NET web applications that use the Control.ResolveUrl method to resolve app-root-relative paths are vulnerable to XSS.
Remediation
Apply context-dependent encoding and/or validation to user input rendered on a page