Reference: https://docs.rapid7.com/insightvm/elevating-permissions/
Spawning a shell using sudo and an escape string is a valid Linux post-exploitation method that can exploit a misconfigured sudoers file and allow a standard user to execute commands as root. ASIC password cracking is used to break hashed passwords, not to elevate privileges. Reading the /etc/passwd file may reveal usernames, but not passwords or privileges. Unquoted service path exploits are applicable to Windows systems, not Linux.
Using the UNION operator is a SQL injection technique, not a Linux post-exploitation method. Verified References:
https://www.comptia.org/blog/what-is-post-exploitationhttps://partners.comptia.org/docs/default-source/resource