We have grouped Layers 5, 6, and 7 of the OSI model corresponding to the TCP/IP Layer 4—application. There are a lot of applications that are known from the past to be vulnerable to exploits. Most of these applications had problems at all of the three upper layers of the OSI model. We will present a few of these applications, known to contain a large number of vulnerabilities, and that are very popular.
BIND (Berkley Internet Name Domain) is the most used DNS server on the Internet. Nowadays, every Linux distribution has a BIND package for DNS services.
The problem with BIND and any DNS server is that in order to be able to translate names into IP addresses it has to communicate with a whole lot of other DNS servers, and so, filtering DNS packets is not possible.
DNS services are vital for internet connection; so in order to disrupt services to victims, attackers have a great interest in bringing down DNS servers. Although BIND...