Definition
ASLR, or Address Space Layout Randomization, is a security technique designed to make it harder for attackers to exploit memory corruption vulnerabilities. It works by randomly arranging the positions of key memory areas, such as the base of the executable, libraries, the stack, and the heap, each time a program is run. This unpredictability makes it significantly more difficult for an attacker to guess the correct memory addresses needed to inject malicious code or redirect program execution. For instance, if a buffer overflow attack relies on knowing the exact location of a return address on the stack, ASLR would shift that address, causing the attack to fail. Unlike full memory encryption which protects data confidentiality, ASLR primarily enhances memory integrity by disrupting predictable memory layouts. This concept is crucial for IT professionals and is frequently tested on certifications like CompTIA Security+ and CISSP.