Which of the following is a common consequence of insufficient transport layer protection?

Insufficient transport layer protection can lead to a variety of serious issues, making the selected answer the most encompassing and accurate.

At the transport layer, protocols like TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) handle the transmission of data between hosts. When these protocols lack adequate protection, it can create vulnerabilities that expose data to multiple risks.

Data leakage can occur because unencrypted data transmitted over a network can be easily intercepted by an attacker, leading to unauthorized access to sensitive information. Additionally, inadequate transport layer security can result in service unavailability. Attackers might exploit vulnerabilities to perform denial-of-service (DoS) attacks that disrupt service and prevent legitimate users from accessing resources.

Unauthorized access is another major consequence; if attackers can intercept or manipulate data packets, they may gain access to systems or data they shouldn't have, leading to further security breaches.

In summary, insufficient transport layer protection can culminate in a variety of adverse outcomes, including data leakage, service unavailability, and unauthorized access. Thus, recognizing that all the mentioned consequences are valid reinforces the understanding of the importance of robust transport layer security measures in protecting data and systems.