> ## Documentation Index
> Fetch the complete documentation index at: https://rootea.es/llms.txt
> Use this file to discover all available pages before exploring further.

# CrossFit

> Verified writeups for the CrossFit machine of Hack The Box

# CrossFit

<p className="machine-summary"><span className="prompt"><code>\$ tldr</code></span> XSS + CSRF bypass → webshell lftp → cron php-shellcommand</p>

<div className="machine-meta">
  | ·                | ·                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
  | ---------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
  | Operating system | Linux                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
  | Difficulty       | Insane                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
  | Vector           | <span className="vbadge vbadge-web">Web</span>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
  | IP               | `10.10.10.208`                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
  | Retirement date  | 2021-03-20                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
  | Skills           | FTP SSL Certificate Enumeration XSS Injection Subdomain Enumeration through the Origin Header \[Access-Control-Allow-Origin] Accessing internal websites through XSS - Creating a javascript file Registering a new user through XSS - CSRF Protection Bypass Uploading a webshell with lftp Cracking Hashes Abusing Cron Job php-shellcommand exploitation - escapeArgs option is not working properly Injecting data into the database to achieve remote command execution (RCE) \[User Pivoting] Binary Analysis - dbmsg \[GHIDRA] Reversing Creating an exploit - Abusing Rand \[Time travel] Abusing symbolic links Injecting our own public key as authorized\_keys in /root |
</div>

## Writeups

| Language | Author      | Format | Link                                                        |
| -------- | ----------- | ------ | ----------------------------------------------------------- |
| 🇪🇸 ES  | **S4vitar** | Vídeo  | [Open](https://www.youtube.com/watch?v=sIaVrGnzRjM)         |
| 🇬🇧 EN  | **0xdf**    | Texto  | [Open](https://0xdf.gitlab.io/2021/03/20/htb-crossfit.html) |
| 🇬🇧 EN  | **IppSec**  | Vídeo  | [Open](https://www.youtube.com/watch?v=Z3Lj_YN0crc)         |

## Skill resources

Curated documentation for each technique listed in the *Skills* column above. Sources: HackTricks, GTFOBins, PortSwigger, etc.

| Skill                             | Source      | Link                                                                                                              |
| --------------------------------- | ----------- | ----------------------------------------------------------------------------------------------------------------- |
| Subdomain Enumeration             | HackTricks  | [Open](https://book.hacktricks.wiki/en/generic-methodologies-and-resources/external-recon-methodology/index.html) |
| Cracking Hashes (hashcat / John)  | HackTricks  | [Open](https://book.hacktricks.wiki/en/generic-methodologies-and-resources/brute-force.html)                      |
| Port Forwarding / Pivoting        | HackTricks  | [Open](https://book.hacktricks.wiki/en/generic-hacking/tunneling-and-port-forwarding.html)                        |
| CSRF (Cross-Site Request Forgery) | PortSwigger | [Open](https://portswigger.net/web-security/csrf)                                                                 |
| Remote Code Execution (RCE)       | HackTricks  | [Open](https://book.hacktricks.wiki/en/pentesting-web/command-injection.html)                                     |
| Cross-Site Scripting (XSS)        | HackTricks  | [Open](https://book.hacktricks.wiki/en/pentesting-web/xss-cross-site-scripting/index.html)                        |
| Cross-Site Scripting (XSS)        | PortSwigger | [Open](https://portswigger.net/web-security/cross-site-scripting)                                                 |

## Related skills worth mastering

Brute Force / Rate-Limit Bypass · Local File Inclusion (LFI) · Remote File Inclusion (RFI) · Shellshock (CVE-2014-6271) · SQL Injection · Server-Side Request Forgery

## If you liked this machine, try

* [Stacked](/en/htb/machines/linux/insano/stacked) — Linux, Insane
* [Joker](/en/htb/machines/linux/dificil/joker) — Linux, Hard
* [Schooled](/en/htb/machines/linux/medio/schooled) — Linux, Medium
* [Undetected](/en/htb/machines/linux/medio/undetected) — Linux, Medium
* [Meta](/en/htb/machines/linux/medio/meta) — Linux, Medium

***

## Comments & tips

Did the official writeup not work? Found a smarter trick? Share it here — comments live in [GitHub Discussions](https://github.com/FFuson/HTB_Writeups/discussions).

<div className="rootea-giscus-wrap" data-giscus-term="machine:crossfit" data-giscus-lang="en" />

*Last updated: 2026-06-07*

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