Previse - Hack The Box
Previse is a easy machine that showcases Execution After Redirect (EAR) which allows users to retrieve the contents and make requests to accounts.php whilst unauthenticated which leads to abusing PHP ‘exec()’ function since user inputs are not sanitized allowing remote code execution against the target, after gaining a www-data shell privilege escalation starts with the retrieval and cracking of a custom MD5Crypt hash which consists of a unicode salt and once cracked allows users to gain SSH access to the target then abusing a sudo executable script which does not include absolute paths of the functions it utilises which allows users to perform PATH hijacking on the target to compromise the machine.
Pilgrimage is an easy-difficulty Linux machine featuring a web application with an exposed ‘Git’ repository. Analysing the underlying filesystem and source code reveals the use of a vulnerable version of ‘ImageMagick’, which can be used to read arbitrary files on the target by embedding a malicious ‘tEXT’ chunk into a PNG image. The vulnerability is leveraged to obtain a ‘SQLite’ database file containing a plaintext password that can be used to SSH into the machine. Enumeration of the running processes reveals a ‘Bash’ script executed by ‘root’ that calls a vulnerable version of the ‘Binwalk’ binary. By creating another malicious PNG, ‘CVE-2022-4510’ is leveraged to obtain Remote Code Execution (RCE) as ‘root’.
‘PermX’ is an Easy Difficulty Linux machine featuring a learning management system vulnerable to unrestricted file uploads via CVE-2023-4220. This vulnerability is leveraged to gain a foothold on the machine. Enumerating the machine reveals credentials that lead to SSH access. A ‘sudo’ misconfiguration is then exploited to gain a ‘root’ shell.
Nunchucks is a easy machine that explores a NodeJS-based Server Side Template Injection (SSTI) leading to an AppArmor bug which disregards the binary AppArmor profile while executing scripts that include the shebang of the profiled application.
This UHC qualifier box was a neat take on some common NodeJS vulnerabilities. First there’s a NoSQL authentication bypass. Then I’ll use XXE in some post upload ability to leak files, including the site source. With that, I’ll spot a deserialization vulnerability which I can abuse to get RCE. I’ll get the user’s password from Mongo via the shell or through the NoSQL injection, and use that to escalate to root. In Beyond Root, a look at characters that broke the deserialization payload, and scripting the NoSQL injection.
Nibbles is a fairly simple machine, however with the inclusion of a login blacklist, it is a fair bit more challenging to find valid credentials. Luckily, a username can be enumerated and guessing the correct password does not take long for most.
Networked is an Easy difficulty Linux box vulnerable to file upload bypass, leading to code execution. Due to improper sanitization, a crontab running as the user can be exploited to achieve command execution. The user has privileges to execute a network configuration script, which can be leveraged to execute commands as root.
Netmon is an easy difficulty Windows box with simple enumeration and exploitation. PRTG is running, and an FTP server with anonymous access allows reading of PRTG Network Monitor configuration files. The version of PRTG is vulnerable to RCE which can be exploited to gain a SYSTEM shell.
Mirai demonstrates one of the fastest-growing attack vectors in modern times; improperly configured IoT devices. This attack vector is constantly on the rise as more and more IoT devices are being created and deployed around the globe, and is actively being exploited by a wide variety of botnets. Internal IoT devices are also being used for long-term persistence by malicious actors.
Love is an easy windows machine where it features a voting system application that suffers from an authenticated remote code execution vulnerability. Our port scan reveals a service running on port 5000 where browsing the page we discover that we are not allowed to access the resource. Furthermore a file scanner application is running on the same server which is though effected by a SSRF vulnerability where it's exploitation gives access to an internal password manager. We can then gather credentials for the voting system and by executing the remote code execution attack as phoebe user we get the initial foothold on system. Basic windows enumeration reveals that the machine suffers from an elevated misconfiguration. Bypassing the applocker restriction we manage to install a malicious msi file that finally results in a reverse shell as the system account.