The SSL certificate chain for this service ends in an unrecognized self-signed certificate.
Description
The X.509 certificate chain for this service is not signed by a recognized certificate authority. If the remote host is a public host in production, this nullifies the use of SSL as anyone could establish a man-in-the-middle attack against the remote host.
Note that this plugin does not check for certificate chains that end in a certificate that is not self-signed, but is signed by an unrecognized certificate authority.
Solution
Purchase or generate a proper SSL certificate for this service.