The remote host is vulnerable to a 'file upload' flaw.
The remote host is running RunCMS, a web-based messaging system. This version of RunCMS is vulnerable to a remote file upload vulnerability. Specifically, when 'Allow custom avatar upload' has been enabled, remote attackers would be able to upload arbitrary files to the server. Successful exploitation would result in arbitary code being executed with the rights of the web application.
Upgrade or patch according to vendor recommendations.