AdmirerToo

Verified writeups for the AdmirerToo machine of Hack The Box

AdmirerToo

$ tldr Adminer SSRF (CVE-2021-21311) → OpenTSDB RCE → Fail2ban privesc

CVE / Bulletins: CVE-2021-21311 ↗ CVE-2020-35476 ↗ CVE-2021-32749 ↗

·	·
Operating system	Linux
Difficulty	Hard
Vector	Web
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]

Writeups

Language	Author	Format	Link
🇪🇸 ES	S4vitar	Vídeo	Open
🇬🇧 EN	0xdf	Texto	Open
🇬🇧 EN	IppSec	Vídeo	Open

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
Subdomain Enumeration	HackTricks	Open
Server-Side Request Forgery	HackTricks	Open

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 — Linux, Medium
• Stacked — Linux, Insane
• Undetected — Linux, Medium
• Meta — Linux, Medium
• RedCross — Linux, Medium

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Last updated: 2026-06-07