Default, self-configured, and incorrect configuration settings may cause a DNS server to function improperly. For example, if a resolving DNS server has been configured to accept recursive requests without any limitations (i.e. from both the internal data network and the Internet), the availability of the server may be significantly impaired due to the increased load. Additionally, the server might become susceptible to DNS reflection attacks as a consequence.

Incorrectly configured DNS servers are also subject to the threat of zone transfers not being limited to authorised DNS servers. This means that every host capable of sending a request to DNS servers can obtain all the domain information of these servers. Data obtained in this way may facilitate future attacks.