Attacks against business logic rules occur when the attacker exploits the domain rules in a malicious way. Such logic attacks have not received sufficient attention in research so far. In this paper, we propose a novel self-protecting approach that defends a system against the exploitation of business logic vulnerabilities. The approach empowers a system with a self-protecting layer to protect it against attacks that misusing business logic rules. The appraoch maintains up-to-date domain knowledge that is analyzed using runtime verification (RV) to detect logical attacks. When attacks are discovered they are dynamically mitigated by applying proper system reconfigurations. We evaluate the approach using a case in the domain of hotel booking systems.