DETECTING AND BLOCKING DOMAIN NAME SYSTEM CACHE POISONING ATTACKS

Concepts and technologies for detecting and blocking Domain Name System (“DNS”) cache poisoning attacks are provided. An inline detector and blocker apparatus implements a detection algorithm to monitor DNS response packets and detects a DNS cache poisoning attack utilizing the detection algorithm. The inline detector and blocker apparatus detects the DNS cache poisoning attack by receiving a DNS response packet and determining that the response packet includes poison data. The poison data may be included within an additional section of the response packet and/or an answer section of the response packet. As appropriate, the inline detector and blocker apparatus removes the additional section and/or the answer section of the response packet to effectively block the poison data from being cached by a DNS caching resolver.