Hetzner шлёт грозные послания об открытом portmapper

Hetzner шлёт грозные послания об открытом portmapper . Что нужно делать?

We have received a security alert from the German Federal Office for Information Security (BSI).

...

> Dear Sir or Madam,

>

> the Portmapper service (portmap, rpcbind) is required for mapping RPC

> requests to a network service. The Portmapper service is needed e.g.

> for mounting network shares using the Network File System (NFS).

> The Portmapper service runs on port 111 tcp/udp.

>

> In addition to being abused for DDoS reflection attacks, the

> Portmapper service can be used by attackers to obtain information

> on the target network like available RPC services or network shares.

>

> Over the past months, systems responding to Portmapper requests from

> anywhere on the Internet have been increasingly abused DDoS reflection

> attacks against third parties.

>

> Please find below a list of affected systems hosted on your network.

> The timestamp (timezone UTC) indicates when the openly accessible

> Portmapper service was identified.

>

> We would like to ask you to check this issue and take appropriate

> steps to secure the Portmapper services on the affected systems or

> notify your customers accordingly.

>

> If you have recently solved the issue but received this notification

> again, please note the timestamp included below. You should not

> receive any further notifications with timestamps after the issue

> has been solved.

>

> Additional information on this notification, advice on how to fix

> reported issues and answers to frequently asked questions:

> <https://reports.cert-bund.de/en/>

>

> This message is digitally signed using PGP. Information on the

> signature key is available at the aforementioned URL.

>

> Please note:

> This is an automatically generated message. Replies to the

> sender address <reports@reports.cert-bund.de> will NOT be read

> but silently be discarded. In case of questions, please contact

> <certbund@bsi.bund.de> and keep the ticket number [CB-Report#...]

> of this message in the subject line.

>

> !! Please make sure to consult our HOWTOs and FAQ available at

> !! <https://reports.cert-bund.de/en/> first.

>

> ======================================================================

>

> Betroffene Systeme in Ihrem Netzbereich:

> Affected systems on your network:

>

> Format: ASN | IP address | Timestamp (UTC)

>  24940 | 88.198.47.24    | 2017-03-09 06:45:58

>

> Mit freundlichen Gren / Kind regards

> Team CERT-Bund

>

> Bundesamt fr Sicherheit in der Informationstechnik (BSI)

> Federal Office for Information Security

> Referat CK22 - CERT-Bund

> Godesberger Allee 185-189, D-53175 Bonn, Germany