Pilgrimage is an easy machine which starts with identifying the ImageMagick tool that the target web application uses to shrink images. The tool is vulnerable to Arbitrary File Reads which enable us to fetch the credentials from a database file. These credentials were used to SSH and gain a user shell. The privilege escalation consists of exploiting Binwalk that runs inside a cron script.
Topology is an easy machine which starts by exploiting LaTeX injection to read files on the server that contain password hashes. After cracking the password hash, it was possible to login via SSH and obtain the user flag. The privilege escalation consisted of enumerating for processes that are run by root. One of the processes being run by root executed “.plt” files in a particular folder to which the user had write permissions. Finally, it was a simple matter of looking up the documentation on running OS commands for that particular extension and use it to gain a shell as root.
Machine Name: Jupiter IP: 10.10.11.216 Difficulty: Medium
Summary
Jupiter is a medium machine that starts with discovering a subdomain that retrieves data from the database using queries sent through the request, making it vulnerable to SQLi. The SQL injection is leveraged to gain a shell as user Postgres. A configuration script writable by Postgres, and run by Juno is used to gain a shell as Juno. Juno is a part of “science” group which uses Jupyter Notebook. The Jupyter service is run by Jovian. The logs of Jupyter can be read by Juno, which are used obtain tokens to login to the Jupyter Hub. The notebook is used to execute commands and gain a shell as Jovian. To escalate privileges as root, a binary which can be run using sudo, uses a configuration file which can be written by Jovian. This misconfiguration is leveraged to gain a shell as root.
Machine Name: Format IP: 10.10.11.213 Difficulty: Medium
Summary
Format is a medium machine that starts with discovering two ports that run Gitea and a Microblog respectively. First, an LFI is discovered on the Microblog after reviewing the source code. Further analysing the source code, one could bypass the mechanism to become Pro user and upload image files. One of the parameters that causes LFI creates a new if it doesn’t already exist. This allowed writing a PHP shell through which a shell was obtained as www-data. A redis server running on a socket was discovered and used to obtain credentials for the user “cooper”. Privilege escalation involved exploiting a python format string vulnerability for a script that could be run using sudo.
MonitorsTwo is an easy machine that starts with exploiting the Cacti monitoring software to gain a shell. The shell obtained is a container host where we find hashes of user in a database file. After cracking the hashes, we obtain the user shell through SSH. Privilege escalation consists of leveraging insufficient permissions on the Docker overlay2 filesystem which allows host users to run privileged binaries on the container. To create a setuid bash binary on the docker container, capsh’s capabilities were misused to gain privileges as root. Finally, the binary was executed on the host machine to obtain a root shell.
Machine Name: OnlyForYou IP: 10.10.11.210 Difficulty: Medium
Summary
OnlyForYou is a medium machine that starts with discovering a subdomain that is vulnerable to LFI. The LFI is used to read the source code of the application. Improper sanitization of user data in the a part of code that executes shell commands was leveraged to gain a shell as www-data. From this shell, two active ports were found, one of which hosted a login page that used default credentials. The dashboard revealed that the application uses Neo4j database. This information was used to test for Cipher injection. The cipher injection was successful and was used to gain password hashes from the database. The cracked hashes were used to login as user John. Privilege escalation involved abusing the “pip3 download” command that could be run as root by the user.
Inject is an easy machine which starts with exploiting an LFI to gain information on the application being built on Spring Framework. Through the LFI, we discover one of the configuration files which reveals that the framework version is vulnerable to RCE. The RCE in Spring Cloud is exploited to gain a shell as user Frank. However, only user Phil can read the user flag. The credentials of Phil were found in another configuration file which was used to switch user to Phil. Privilege Escalation consisted of checking for cronjobs and looking for vulnerabilities in the jobs running as root. Ansible was being run on all the “.yml” files, which was exploited to gain access as root.
Machine Name: Investigation IP: 10.10.10.197 Difficulty: Medium
Summary
Investigation is a medium machine that has a web server vulnerable to command injection vulnerability. With enough enumeration, it is easy to exploit command injection. However, it only leads to a shell as www-data. Getting a user shell requires some log file analysis and common sense. Privilege escalation deals with binary analysis and code review.
Machine Name: Red Panda IP: 10.10.11.170 Difficulty: Easy
Summary
Red Panda is an easy machine (not really) that exploits SSTI in Java Spring Boot to get an RCE. To escalate privileges to root, enumeration of directories, permissions, identities, groups, processes, and files need to be chained together to exploit a file that runs as a cronjob as root. The main attack involves performing an XXE attack to gain access to the private key of root.
Machine Name: Paper IP: 10.10.11.143 Difficulty: Easy
Summary
Paper is a relatively easy box and teaches enumeration and a bit of reading API documentations. It forces the attacker to keep looking for sensitive information that can be utilized to run commands and eventually get a shell. To get a user shell, we find credentials on the system through a chat bot. They can be used for logging in through SSH. Another way was to find a command hidden from the ones listed by the bot by reading the API documentation or finding a scripts directory to run commands as user and get a shell. Escalating privileges as root was simple as it was vulnerable to a popular vulnerability with a simple PoC.
