Privilege Escalation in the Bash Shell

Privilege escalation is a critical aspect of pentesting in Unix and Linux environments. This chapter explores the techniques and methodologies for identifying and exploiting vulnerabilities that allow an attacker to elevate their privileges within a system. We will focus on utilizing the Bash shell, a powerful tool present in most Unix-based systems, to execute various privilege escalation strategies.

Throughout this chapter, we will examine common privilege escalation vectors, develop Bash scripts for system enumeration, and analyze the exploitation of misconfigurations in services and scheduled tasks. Special attention will be given to understanding and leveraging Set User ID (SUID) and Set Group ID (SGID) binaries, which often provide opportunities for privilege escalation. By mastering these techniques, pentesters can effectively assess and improve the security posture of Unix and Linux systems.

We cover only the most common privilege...