What's privilege escalation?

It's a specific buffer overflow attack technique that uses rainbow tables.

It's when an attacker gains elevated access to computer systems by exploiting defects in entities such as applications and operating systems.

It's when an attacker commands a botnet to brute force attack a password.

It's when an attacker gains access to computer systems by social engineering themselves into a promotion of job title/position.

Explanation

Privilege escalation is when an attacker gains elevated access to computer resources that are protected from an application or user by exploiting defects in entities such as applications and operating systems. Not all privilege escalation involve exploiting defects, however.