Hack the Box

Support is an Easy difficulty Windows machine that features an SMB share that allows anonymous authentication. After connecting to the share, an executable file is discovered that is used to query the machines LDAP server for available users. Through reverse engineering, network analysis or emulation, the password that the binary uses to bind the LDAP server is identified and can be used to make further LDAP queries. A user called support is identified in the users list, and the info field is found to contain his password, thus allowing for a WinRM connection to the machine. Once on the machine, domain information can be gathered through SharpHound, and BloodHound reveals that the Shared Support Accounts group that the support user is a member of, has GenericAll privileges on the Domain Controller. A Resource Based Constrained Delegation attack is performed, and a shell as NT Authority System is received.

RedPanda is an easy Linux machine that features a website with a search engine made using the Java Spring Boot framework. This search engine is vulnerable to Server-Side Template Injection and can be exploited to gain a shell on the box as user woodenk. Enumerating the processes running on the system reveals a Java program that is being run as a cron job as user root. Upon reviewing the source code of this program, we can determine that it is vulnerable to XXE. Elevation of privileges is achieved by exploiting the XXE vulnerability in the cron job to obtain the SSH private key for the root user. We can then log in as user root over SSH and obtain the root flag.