Allaire JRun contains a flaw that allows a remote cross site scripting attack. This flaw exists because the application does not validate user input upon submission to the Java Servlet which is in turn passed to the error handler. This could allow a user to create a specially crafted URL that would execute arbitrary code in a user's browser within the trust relationship between the browser and the server, leading to a loss of integrity.
Currently, there are no known workarounds or upgrades to correct this issue.
However, Macromedia has released a patch to address this vulnerability.