Cache Poisoning Raises Cash Crop for DNS Pharmers

Executive Summary

DNS (Domain Name System) servers let us navigate the Internet in real time and are critical to network security. They match the names of network resources and websites with unique numerical addresses. This information is cached for other users of the system. Cache poisoning is an attack where a DNS server receives bogus information but is not aware that the information is invalid. This directly affects all users of the server, and indirectly, other DNS servers. Once a DNS server is compromised, pharming then redirects traffic intended for a certain resource or website to another location. This white paper briefly explores these and other vulnerabilities, as well as methods for securing DNS services.