What is purpose of execute disable bit?

The Execute Disable Bit (XD Bit) is a security feature found in modern processors that helps prevent the execution of code in certain regions of memory, such as the stack and heap, which are typically used for data storage. By marking these areas as non-executable, it protects against certain types of malware and buffer overflow attacks that attempt to execute malicious code. This feature enhances system security by ensuring that only designated executable memory can run code, thereby reducing the risk of unauthorized code execution.