SYN flooding attacks exploit the TCP three-way handshake mechanism where a client sends SYN, server responds with SYN-ACK, and client completes with ACK. The attacker sends many SYN packets but never completes the handshake, exhausting server resources. This attack does not target IIS or Netscape vulnerabilities specifically, and SCTP uses a four-way handshake which is not the target of SYN flooding.