easy.c

/** Easily exploitable Buffer Overflow for learning purposes
 *
 * Compilation:
 *  gcc -fno-stack-protector -z execstack -m32 -o easy easy.c
**/

#include <string.h>
#include <stdio.h>
#include <stdlib.h>

void vulnerable(char * input) {
    char buffer[1024];

    strcpy(buffer, input);

    printf("Input: %s\n", buffer);
}

int main (int argc, char * argv[]) {

    if (argc != 2)
        exit(1);

    vulnerable(argv[1]);
}