We recently emailed some of our customers about an attack that could affect their Virtual Private Servers or Dedicated Servers. There is a misconfiguration causing their DNS servers to answer queries from any host (this is also called recursive DNS queries).
Attackers use this misconfiguration to perform DNS attacks against other Internet services. For more information on these attacks, please see this blog post.
To prevent these attacks they need to reconfigure and lock down their DNS servers. For more information see these articles:
How do I disable recursive DNS queries on my Windows Dedicated or Virtual Private Server?
How do I disable recursive DNS queries on my Windows server with Parallels Plesk Panel?
How do I disable recursive DNS queries on my Linux VPS or Dedicated Server?