h4cker/buffer_overflow_example/strcpy_example2.c

#include <stdio.h> 
#include <string.h> 
#include <stdlib.h> 
  
int main(int argc, char *argv[]) 
{ 
  
       // Reserve 5 byte of buffer plus the terminating NULL. 
       // should allocate 8 bytes = 2 double words, 
       // To overflow, need more than 8 bytes... 
       char buffer[5];  // If more than 8 characters input 
                        // by user, there will be access  
                        // violation, segmentation fault 
  
       // a prompt how to execute the program... 
       if (argc < 2) 
       { 
              printf("strcpy() NOT executed....\n"); 
              printf("Syntax: %s <characters>\n", argv[0]); 
              exit(0); 
       } 
  
       // copy the user input to mybuffer, without any 
       // bound checking a secure version is srtcpy_s() 
       strcpy(buffer, argv[1]); 
       printf("buffer content= %s\n", buffer); 
  
       // you may want to try strcpy_s() 
       printf("strcpy() executed...\n"); 
  
       return 0; 
}