Root access allows a user or process to read, change and execute almost anything permitted by the operating system. It can alter protected files, manage accounts, control services and change security settings.
Obtaining root access from a restricted starting point is a form of privilege escalation. In a cybersecurity evaluation, reaching root on a hardened test system indicates that multiple defensive boundaries may have been overcome.
ELI5
Root access is like having the master key and control panel for a computer. Ordinary users receive only the keys they need, while root can open and change nearly everything.
For example, a normal account may be unable to replace a system program, but a process with root access can usually modify that protected program.
Why is unauthorized root access dangerous?
It can let an attacker disable defenses, steal protected data, install persistent software and take broad control of the machine.
Is root access always malicious?
No. Administrators legitimately use it for system management, and researchers may obtain it in explicitly authorized security tests.
