Linux privesc: SUID binaries (run as file owner), sudo misconfigurations (sudo -l to list allowed commands), writable cron jobs (write to script run as root), PATH hijacking, kernel exploits.
LinPEAS automates Linux privilege escalation enumeration. GTFObins documents how to exploit SUID/sudo binaries for escalation. Misconfigured sudo is the most common Linux privesc path in CTFs and real environments. Check /etc/crontab and /etc/passwd for weak permissions.