Cross-site scripting (XSS) vulnerability in the ProcessRequest function in mcs/class/System.Web/System.Web/HttpForbiddenHandler.cs in Mono 2.10.8 and earlier allows remote attackers to inject arbitrary web script or HTML via a file with a crafted name and a forbidden extension, which is not properly handled in an error message.
Improper Neutralization of Input During Web Page Generation The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.