Definition
Data Execution Prevention (DEP) is a security feature built into modern operating systems and processors designed to protect against malicious code execution. It works by marking specific areas of memory as non-executable, preventing programs from running code from these designated regions. This is crucial for preventing buffer overflow attacks, a common method used by malware to inject and execute harmful instructions. For instance, DEP can stop a virus from overwriting legitimate program code with its own malicious payload. Unlike antivirus software which actively scans for known threats, DEP is a proactive defense mechanism that limits the attack surface. You will encounter DEP concepts on CompTIA Security+, CySA+, and CISSP certification exams.