UltraTech is a web hacking challenge that involves enumerating a corporate site and an API belonging to a fictional blockchain company to leak credentials via a command injection vulnerability. After we get a shell we’ll abuse the fact that our user is able to run docker to spawn a root shell.

Lian_Yu is a beginner friendly CTF mostly focused on enumeration. We’ll fuzz a website to find credentials that will get us access to the FTP service. There we’ll find an image file to perform steganalysis on, and that will reveal a password we can use to SSH into the box. Escalating to root from there is just a matter of escaping from a binary we have sudo privileges for.

Brooklyn Nine Nine is an easy Linux box with 2 different ways to get user shells and to escalate privileges. We’ll cover both solutions here.

Dogcat involves one of my favorite techniques: log file poisoning. We’ll start by enumerating a webapp and finding a LFI bug. Then we can poison the web server’s logs to escalate the LFI to RCE and pop a user shell. From there, getting root is almost too easy. That’s because we’ll find ourselves inside a Docker container, and the final challenge will be escaping to a root shell on the host.

Anonymous is a simple and straightforward Linux box where we’ll take advantage of a misconfigured FTP service to get a shell. From there we’ll escalate our privileges through another misconfiguration, this time through a root-owned binary with SUID permissions.