Properly - Su Must Be Suid To Work

: The primary purpose of su is to allow users to assume the identity of another user, usually to gain elevated privileges. If su were not SUID, users would not be able to switch to a different user account (such as root) because they wouldn't have the necessary permissions to do so.

The su (substitute user) command allows a user to switch to another user account (typically root) without logging out. For su to work as intended, it have the SUID (Set User ID) bit set. This article explains why this permission is critical and what happens if it’s missing. su must be suid to work properly

In the architecture of Unix-like operating systems, few concepts are as fundamental—or as frequently misunderstood—as the divide between the regular user and the superuser (root). The command su (substitute user) is the gatekeeper between these two worlds. It allows a user to switch to another user account, most commonly the root account. : The primary purpose of su is to

Notice the permissions. Only root can read and write to this file (members of the shadow group may also read it depending on the distro). For su to work as intended, it have