Friendzone is an easy box with some light enumeration of open SMB shares and sub-domains. I used an LFI vulnerability combined with a writable SMB share to get RCE and a reverse shell. A cron job running as root executes a python script every few minutes and the OS module imported by the script is writable so I can modify it and add code to get a shell as root.
Hackback took me a long time to do. There are so many steps required just to get a shell. For extra difficulty, AppLocker is enabled and an outbound firewall policy is configured to block reverse shells. This box has a bit of everything: fuzzing, php, asp (for pivoting with reGeorg), command injection in a Powershell script, some light reversing. For the privesc, I used the diaghub vulnerability and modified an existing exploit to get a bind shell through netcat.
I think Netmon had the quickest first blood on HTB yet. The user flag could be grabbed by just using anonymous FTP and retrieving it from the user directory. I guessed the PRTG admin password after finding an old backup file and changing the year in the password from 2018 to 2019. Once inside PRTG, I got RCE as SYSTEM by creating a sensor and using Nishang’s reverse shell oneliner.
To solve Querier, we find an Excel spreadsheet that contains a VBA macro then use Responder to capture NTLM hashes from the server by forcing it to connect back to our machine with xp_dirtree. After cracking the hash, we gain RCE on the server by using the standard xp_cmdshell command. The Administator credentials are found in a Group Policy Preference file.
Flujab was without a doubt one of the toughest HTB box. It’s got a ton of vhosts that force you to enumerate a lot of things and make sure you don’t get distracted by the quantity of decoys and trolls left around. The key on this box is to stay ‘in scope’ as the box author hinted at before the box was released, so that means enumerating two specific domains without getting distracted by all the other stuff on the box.
Help showed that a small programming mistake in a web application can introduce a critical security vulnerability. In this case, the PHP application errors out when uploading invalid extensions such as PHP files but it doesn’t delete the file. Combined with a predictable filename generated based on MD5 of original file + epoch, we can get RCE.
Sizzle was an amazing box that requires using some Windows and Active Directory exploitation techniques such as Kerberoasting to get encrypted hashes from Service Principal Names accounts. The privesc involves adding a computer to domain then using DCsync to obtain the NTLM hashes from the domain controller and then log on as Administrator to the server using the Pass-The-Hash technique.
Chaos starts with some enumeration to find a hidden wordpress site that contains a set of credentials for a webmail site. There’s some simple crypto we have to do to decrypt an attachment and find a hidden link on the site. We then exploit the PDF creation website which uses LaTeX and gain RCE. After getting a reverse shell, we do some digging into the user’s folders and find the webmin root credentials stored in the Firefox user profile.
Conceal uses IPSec to secure connectivity to the server and nothing is exposed by default except SNMP and IPSec. After finding the preshared key by enumerating with SNMP, we connect to the server, upload an ASP payload to gain RCE then privesc to SYSTEM using RottenPotato. Not a bad box overall, but the initial part of figuring out the IPSec configuration parameters took me a while to figure out/guess.
Lightweight was a fun box that uses Linux capabilities set on tcpdump so we can capture packets on the loopback interface and find credentials in an LDAP session. We then find more credentials in the source code of the web application and finally priv esc to root by abusing a copy of the openssl program that all has Linux caps set on it.