What is a common consequence of a successful application layer attack?

A successful application layer attack typically targets vulnerabilities within the application itself, which can lead to unauthorized access to sensitive information. This type of attack can exploit weaknesses in the application's code or its configurations, allowing an attacker to gain access to data that they should not have permission to view or manipulate. This unauthorized access may result in data theft, data loss, or even data corruption, depending on the nature of the attack and the security measures in place.

The other options present scenarios in which an application could undesirably improve or a situation that enhances user engagement or compliance, but these outcomes do not align with the typical consequences of an application layer attack. Instead, these consequences often lead to greater risks for the organization, including reputational damage, legal ramifications, and financial loss associated with breach remediation and data recovery efforts. Hence, the most accurate and realistic consequence of such an attack is indeed unauthorized data access and potential data loss.