The remote host is vulnerable to a remote 'file include' flaw.
The remote host is running Squirrelmail, a web-based email client. This version of Squirrelmail is vulnerable to a 'file include' flaw within the redirect.php script. An attacker exploiting this flaw would be able to execute local commands. This can lead to the reading, writing or deletion of critical data. To exploit this flaw, the attacker would only need to be able to send web requests to the server.
Upgrade to version 1.4.8 or higher.