Recent Posts

Zetta - Hack The Box

Zetta is another amazing box by jkr. The first part was kinda tricky because you had to pay attention to the details on the webpage and spot the references to IPv6 that lead you to the EPTR command to disclose the IPv6 address of the server. Then there’s some light bruteforcing of rsync’s credentials with a custom bruteforce script and finally a really cool SQL injection in a syslog PostgreSQL module.

JSON - Hack The Box

To get remote code execution on JSON, I exploited a deserialization vulnerability in the web application using the Json.net formatter. After getting a shell I could either get a quick SYSTEM shell by abusing SeImpersonatePrivileges with Juicy Potato or reverse the Sync2FTP application to decrypt its configuration and find the superadmin user credentials.

RE - Hack The Box

I had fun solving RE but I did it using an unintended path. After getting a shell with a macroed .ods file, I saw that the Winrar version had a CVE which allowed me to drop a webshell in the webserver path and get RCE as iis apppool\re. The user had access to modify the UsoSvc service running with SYSTEM privileges so it was trivial at that point to get a SYSTEM shell. Because the root flag was encrypted for user Coby, I used meterpreter to impersonate his token and read the file.

Mini WebSocket CTF

During the holidays, @stackfault (sysop from the BottomlessAbyss BBS) ran a month long CTF with challenges being released every couple of days. Some of challenges were unsolved or partially solved challenges from earlier HackFest editions as well as some new ones. There was also a point depreciation system in place so challenges solved earlier gave more points. This post is a writeup for the Evilconneck challenge, a quick but fun challenge with websockets and a bit of crypto.

AI - Hack The Box

Exploiting the simple SQL injection vulnerability on the AI box was harder than expected because of the text-to-speech conversion required. I had to use a few tricks to inject the single quote in the query and the other parameters needed for the injection.

Player - Hack The Box

Player was a tough one. Getting the initial shell on Player took me quite some time. Every time I got new credentials I thought I would be able to log in but there was always another step after. The trickiest part of the box for me was finding the .php~ extension to read the source code of the page. I had the hint from the chat application but I couldn’t connect the dots.

Bitlab - Hack The Box

I solved this gitlab box the unintended way by exploiting the git pull command running as root and using git post-merge hooks to execute code as root. I was able to get a root shell using this method but I still had to get an initial shell by finding the gitlab credentials in some obfuscated javascript and modifying PHP code in the repo to get RCE.

Craft - Hack The Box

Craft was a fun Silicon Valley themed box where we have to exploit a vulnerable REST API eval function call to get RCE. After getting a shell on the app container, we escalate to a user shell on the host OS by finding credentials and SSH private keys. To gain root access, we have to generate an OTP token with the vault software installed on the machine.

Smasher2 - Hack The Box

Just its predecessor, Smasher2 is a very difficult box with reverse engineering and binary exploitation. Unfortunately, the initial step required some insane brute-forcing which took part of the fun out of this one for me. I solved the authentication bypass part using an unintended method: The code compares the password against the username instead of the password in the configuration file so by guessing the username I also had the password and could log in. I had to do some WAF evasion to get my payload uploaded and land a shell. Then the final part of the box is exploiting a kernel driver mmap handler to change the credential structure in memory of my current user to get root access.

Wall - Hack The Box

Wall is running a vulnerable version of the Centreon application that allows authenticated users to gain RCE. The tricky part of this box was finding the path to the application since it’s not something that normally shows up in the wordlists I use with gobuster. The intended way was to bypass the HTTP basic auth by using a POST then the redirection contained a link to the centreon page but instead I did some recon on the box creator’s website and saw that he had written an exploit for Centreon and guessed the path accordingly. The priv esc was the same used on Flujab: a vulnerability in screen that allows the attacker to write to any file on the system.