What type of attack allows an insider to gain unauthorized access to confidential data by exploiting system permissions?

A privilege escalation attack occurs when an insider, who may have limited access rights or permissions, exploits vulnerabilities within a system to gain elevated privileges. This type of attack can often involve manipulating software vulnerabilities, leveraging misconfigurations, or taking advantage of weak security policies that allow a user to access confidential data they are not authorized to view.

The ability to escalate privileges is particularly concerning because it allows individuals to bypass the normal access controls that are in place to protect sensitive information. This could lead to unauthorized viewing, modification, or even deletion of data. The implications of such an attack are significant, as they can compromise the integrity, confidentiality, and availability of an organization's sensitive information.

In contrast, other types of attacks listed do not focus primarily on the exploitation of system permissions. SQL injection attacks target databases by injecting malicious SQL queries, Trojan horse attacks involve disguising malicious software as legitimate, and denial of service attacks focus on overwhelming systems to render them unusable. These attacks do not primarily revolve around the exploitation of user privileges to access confidential data.