SWFUpload is prone to a cross-site scripting vulnerability because it fails to sanitize user-supplied input. An attacker may leverage this issue to execute arbitrary script code in the browser of an unsuspecting user in the context of the affected site. This may allow the attacker to steal cookie-based authentication credentials and launch other attacks. SWFUpload version 220.127.116.11 is vulnerable; prior versions may also be affected.
SWFUpload applet is installed on a large number of applications. The fix is different on each affected application. Please consult the application vendor for information on how to fix this vulnerability.