Buffer Overflow Exploitation is the technique of writing more data into a memory buffer than it can hold, overwriting adjacent memory (return addresses, pointers, data). An attacker crafts input to overwrite specific memory locations, redirecting program flow to malicious code or leaking sensitive data. It's a fundamental vulnerability class affecting low-level code (C/C++). Understanding buffer overflows is essential for penetration testers, security researchers, and incident responders. It teaches memory layout, CPU architecture, and system-level security fundamentals. High salaries reflect the specialized knowledge required and ongoing relevance in legacy system assessments.