What is privilege escalation?

Before we get into any technical details about privilege escalation, let's first get a basic understanding of privileges. The literal dictionary meaning of the word privilege is a special right, advantage, or immunity granted or available only to a particular person or group. When it comes to the computing world, privileges are something that are managed by the operating system. There might be ten users on a single system, but not all may have the same level of privileges. As per security best practices, the principle of least privilege is often followed. That means each user is assigned only those bare-minimum privileges that are absolutely essential to perform their tasks. This principle helps eliminate the possibility of the abuse of unnecessary, excessive privileges.

In the context of security assessments, privilege escalation becomes an important factor. Let's assume you have managed to successfully exploit a vulnerability in a remote system and got SSH...