Which security feature blocks execution in a non-executable memory location?

Which security feature blocks execution in a non-executable memory location?

• A. Data Execution Prevention (DEP)
• B. Address Space Layout Randomization (ASLR)
• C. User Account Control (UAC)
• D. Secure Boot

Answer: (A)

Data Execution Prevention blocks execution in memory locations that aren’t meant to run code. It uses the processor’s NX (or XD) bit to mark pages as non-executable, so even if an attacker injects code into regions like the stack or heap, the CPU will not execute it. This directly stops many common exploits such as buffer overflows and return-oriented programming by preventing code from running where it shouldn’t. The other options address different goals: ASLR makes it harder to predict where code and data live, complicating exploits but not inherently stopping execution; UAC controls privilege elevation for user actions; Secure Boot ensures the system boots with trusted software, not runtime memory execution rights.

Data Execution Prevention blocks execution in memory locations that aren’t meant to run code. It uses the processor’s NX (or XD) bit to mark pages as non-executable, so even if an attacker injects code into regions like the stack or heap, the CPU will not execute it. This directly stops many common exploits such as buffer overflows and return-oriented programming by preventing code from running where it shouldn’t. The other options address different goals: ASLR makes it harder to predict where code and data live, complicating exploits but not inherently stopping execution; UAC controls privilege elevation for user actions; Secure Boot ensures the system boots with trusted software, not runtime memory execution rights.