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 flaw. Specifically, an attacker can create a malicious .php3 or .php5 script and upload it to the RunCMS server. The attacker can then invoke the script, causing arbitrary code to be run on the RunCMS system.
Upgrade to version 1.3a3 or higher, when available.