Summary Postman is an easy-rated Linux machine on HackTheBox. The box exposes an unauthenticated Redis instance that allows writing an SSH public key to the redis user's .ssh directory, granting initial shell access. From there, an encrypted RSA private key belonging to user Matt is recovered, cracked offline with John the Ripper, and reused (due to password reuse) to su into Matt for the user flag. Enumeration of Matt's owned files reveals a hint pointing to the previously unchecked Webmin serv