An attack that takes advantage of the procedures for initiating a session is known as what type of attack?

SYN flood attack.

Explanation:

The transport layer of the OSI network model is the four layer is the model. It provides a medium of transportation between two computers in the network. It segments packets to smaller chunks for easier transmission. The PDU of the layer is called segment.

UDP and TCP are examples of the protocols found in this layer

The UDP is a connectionless transmission while the tcp is connection oriented, which means that it must establish a connection for transmission to take place. It is susceptible to SYN flood attacks because it reply to SYN with and ACK message. For this reason, an attacker could flood all of it ports with an ICMP request echo message.