Windows Privesc Privilege Escalation via Unquoted Service Paths on Windows
How unquoted Windows service paths with spaces let low-privileged users plant a binary and escalate to SYSTEM, plus blue-team defenses.
oscp
Windows Privesc 
Linux Privesc PATH Hijacking: Privilege Escalation via Writable PATH Directories and Relative Binaries
How attackers abuse relative paths and writable PATH directories to plant malicious binaries and escalate privileges on Linux.
Linux Privesc Linux Enumeration Cheat Sheet for Privilege Escalation
A practical Linux post-exploitation enumeration cheat sheet covering id, uname -a, sudo -l, SUID hunting, and process inspection.
RE & Pwn Stack-Based Buffer Overflows: From Crash to Shell
A practical walkthrough of classic stack-based buffer overflows: EIP control, offset discovery, bad chars, and shell.