Buffer Overflow Exploitation Basics

What is Buffer Overflow?

Occurs when a program writes more data to a buffer than it can hold.

Stack-Based Overflows

Target the call stack. EIP is overwritten with attacker-controlled data.

void vulnerable(char *input) {
    char buf[64];
    strcpy(buf, input);
}

Mitigations

ASLR, NX/DEP, and stack canaries are modern defenses.