Intypedia, the Information Security Encyclopedia has just given its 13th lesson under the title "DNS Security". The video for the lesson was created by several GMV professionals, including Javier Osuna García-Malo de Molina, Head of GMV’s Processes and Security Consultancy Division, together with Isidro Labrador and Manuel Collado.

The Domain Name System (DNS) is widely used in the Internet, and the aim of this lesson was to analyse its utility, weakness and anti-attack measures.
DNS enables more or less descriptive “human” addresses to be translated into “machine” addresses, in our case IP addresses. For example, it is much easier to memorise or even guess the meaning of the UPM university address “www.upm.es” than to work with its IP address, which is “138.100.200.6”. It also facilitates, among other functions, the sending of emails.

Public organisations and companies are well aware of this system’s importance and the possible impact of its unavailability. Maximum security measures are therefore taken on the most important items of the system such as the root servers that are prone to DoS attacks.

Nowadays, without DNS architecture internet communications would be much more difficult: website access, sending emails, etc. Today’s hackers often exploit the DNS for phishing, spying or stealing information.

The best way of warding off attacks of this sort is the following: keep secure access control, raise user awareness of the existence and methods of social engineering, ensure traceability of why and when DNS-contained information was modified and by whom, run an efficient monitoring system, use only the latest DNS-related software versions which are continually updated, configure the DNS properly and limit the number of networks from which the DNS cache can be accessed, where possible.