Which type of attack is characterized by leaving unsecured connections open?

A half-open attack typically exploits the TCP three-way handshake process but does not fully establish a connection. In this scenario, the malicious actor sends a SYN packet to the target system but never completes the handshake by sending the corresponding ACK packet. As a result, the connection remains in a half-open state.

This can lead to several issues, such as resource exhaustion on the target system, which may ultimately result in a denial of service. Since these half-open connections consume system resources, if enough are left open, legitimate users may be unable to establish connections when needed. The key characteristic of this attack is the deliberate action of leaving connections partially open, thereby putting strain on the target system.

Understanding this type of attack is crucial in the context of cybersecurity, as it illustrates a manipulation of the standard protocols that can have significant effects on system availability and performance. Recognizing the nature of half-open attacks allows cybersecurity professionals to implement appropriate defenses, such as SYN cookies or timeouts for incomplete connections, to mitigate these risks.