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.
https://hermes.opensuse.org/messages/15374367
https://bugzilla.novell.com/show_bug.cgi?id=769799
http://www.openwall.com/lists/oss-security/2012/07/06/11
http://www.mandriva.com/security/advisories?name=MDVSA-2012:140