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

# AdmirerToo

> Verified writeups for the AdmirerToo machine of Hack The Box

# AdmirerToo

<p className="machine-summary"><span className="prompt"><code>\$ tldr</code></span> Adminer SSRF (CVE-2021-21311) → OpenTSDB RCE → Fail2ban privesc</p>

<div className="cve-row"><span className="cve-row-label">CVE / Bulletins:</span> <a className="cve-chip" href="https://nvd.nist.gov/vuln/detail/CVE-2021-21311" target="_blank" rel="noopener">CVE-2021-21311 ↗</a> <a className="cve-chip" href="https://nvd.nist.gov/vuln/detail/CVE-2020-35476" target="_blank" rel="noopener">CVE-2020-35476 ↗</a> <a className="cve-chip" href="https://nvd.nist.gov/vuln/detail/CVE-2021-32749" target="_blank" rel="noopener">CVE-2021-32749 ↗</a></div>

<div className="machine-meta">
  | ·                | ·                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
  | ---------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
  | Operating system | Linux                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
  | Difficulty       | Hard                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
  | Vector           | <span className="vbadge vbadge-web">Web</span>                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
  | IP               | `10.10.11.137`                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
  | Retirement date  | 2022-05-28                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
  | Skills           | Subdomain Enumeration Adminer Enumeration SSRF (Server Side Request Forgery) in Adminer \[CVE-2021-21311] Abusing redirect to discover internal services OpenTSDB Exploitation \[CVE-2020-35476] \[Remote Code Execution] Searching for valid metrics OpenCats PHP Object Injection to Arbitrary File Write Abusing Fail2ban \[Remote Code Execution] (CVE-2021-32749) Playing with phpggc in order to serialize our data Abusing whois config file + OpenCats + Fail2ban \[Privilege Escalation] |
</div>

## Writeups

| Language | Author      | Format | Link                                                          |
| -------- | ----------- | ------ | ------------------------------------------------------------- |
| 🇪🇸 ES  | **S4vitar** | Vídeo  | [Open](https://www.youtube.com/watch?v=YmZLdJRBKv0)           |
| 🇬🇧 EN  | **0xdf**    | Texto  | [Open](https://0xdf.gitlab.io/2022/05/28/htb-admirertoo.html) |
| 🇬🇧 EN  | **IppSec**  | Vídeo  | [Open](https://www.youtube.com/watch?v=446sWtb5bc4)           |

## Skill resources

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

| Skill                       | Source     | Link                                                                                                              |
| --------------------------- | ---------- | ----------------------------------------------------------------------------------------------------------------- |
| Remote Code Execution (RCE) | HackTricks | [Open](https://book.hacktricks.wiki/en/pentesting-web/command-injection.html)                                     |
| Subdomain Enumeration       | HackTricks | [Open](https://book.hacktricks.wiki/en/generic-methodologies-and-resources/external-recon-methodology/index.html) |
| Server-Side Request Forgery | HackTricks | [Open](https://book.hacktricks.wiki/en/pentesting-web/ssrf-server-side-request-forgery/index.html)                |

## Related skills worth mastering

Local File Inclusion (LFI) · Remote File Inclusion (RFI) · Shellshock (CVE-2014-6271) · Cross-Site Scripting (XSS)

## If you liked this machine, try

* [Time](/en/htb/machines/linux/medio/time) — Linux, Medium
* [Stacked](/en/htb/machines/linux/insano/stacked) — Linux, Insane
* [Undetected](/en/htb/machines/linux/medio/undetected) — Linux, Medium
* [Meta](/en/htb/machines/linux/medio/meta) — Linux, Medium
* [RedCross](/en/htb/machines/linux/medio/redcross) — 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:admirertoo" data-giscus-lang="en" />

*Last updated: 2026-06-07*

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