pkexec - 122-3 main

polkit is an application-level toolkit for defining and handling the policy
that allows unprivileged processes to speak to privileged processes.
It was previously named PolicyKit.
.
pkexec is a setuid program to allow certain users to run commands as
root or as a different user, similar to sudo. Unlike sudo, it carries
out authentication and authorization by sending a request to polkit,
so it uses desktop environments' familiar prompting mechanisms for
authentication and uses polkit policies for authorization decisions.
.
By default, members of the 'sudo' Unix group can use pkexec to run any
command after authenticating. The authorization rules can be changed by
the local system administrator.
.
If this functionality is not required, removing the pkexec package will
reduce security risk by removing a setuid program.