Information, Computer and Network Security Terms Glossary and
Syn Attack refers to an attacker sending a series of SYN requests using a fake IP source address to a target (victim). The target sends a SYN ACK in response and waits for an ACK to come back to complete the session set up. Since the source address is fake, the response never comes. The SYN requests from the attacker fill the victim's memory buffers so that it can no longer accept legitimate session requests.